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Flashcards in Hand Tumors Deck (51):
1

A 34-year-old woman comes for evaluation because of a 4-month history of pain in the fingers of the right hand. The pain is most severe in the ring finger and is exacerbated by exposure to cold temperatures. Physical examination shows a blue discoloration under the nail of the ring finger. Which of the following is the most likely diagnosis?

A) Cutaneous melanoma
B) Epidermal inclusion cyst
C) Giant cell tumor
D) Glomus tumor
E) Mucous cyst

The correct response is Option D.

Glomus tumors are benign neurovascular tumors. The glomus apparatus is believed to function as a thermoregulatory control mechanism. Glomus tumors generally are found in the hand, most commonly in the digit, and often in the fingertip. They are characterized by severe pain, especially with exposure to cold temperatures. Cold sensitivity can be evoked by placing the digit in an ice bath. Glomus tumors are well visualized on MRI using T-1 and T-2 weighted images. Ultrasonography may also be useful in identifying glomus tumors. Treatment for glomus tumors is complete surgical excision. Up to 25% of these tumors may have multiple lesions.

Malignant melanomas may be seen in the subungual area. These tumors usually are identified by a pigmented streak under the fingernail. These tumors are generally painless and often go unrecognized. A pigmented lesion under the nail should be biopsied if it does not resolve by 4 weeks.

Giant cell tumors are benign soft-tissue tumors. They are the second most common tumor in the hand. These tumors generally occur on the volar surface of the fingers and hand. They present as a firm, nodular, nontender mass.

Epidermal inclusion cysts are benign masses of the hand thought to be the result of implantation of the epithelial cells into the underlying soft tissue. They produce a painless mass. Treatment of these cysts is by marginal excision.

A mucous cyst is a term used to describe a ganglion cyst of the distal interphalangeal (DIP) joint. This is a misnomer because the cysts are not filled with a mucous material, but synovial fluid. The cyst may produce nail deformities. Pain may be associated with these cysts, and is caused by the underlying arthritis of the DIP joint.

 

2

A 30-year-old woman comes to the office for consultation regarding a 2-year history of a slow-growing mass on the volar aspect of the left ring finger. The growth is adjacent to the distal interphalangeal (DIP) joint. Physical examination shows the mass is firm and cannot be transilluminated. The overlying skin is intact. Which of the following is the most likely diagnosis?

A) Desmoid tumor
B) Ganglion cyst
C) Giant cell tumor
D) Pyogenic granuloma
E) Vascular tumor

The correct response is Option C.

The mass described in this scenario is a giant cell tumor of the tendon sheath. These growths are common in adults younger than 50 years of age. These masses are slow-growing, firm, lobulated, and painless. Giant cell tumors are the second most common tumor of the hand, after ganglion cysts. Unlike ganglion cysts, giant cell tumors cannot be transilluminated. Moreover, they usually occur on the volar aspect of the hand, and bone invasion is not commonly seen. These characteristics are not true of vascular tumors, desmoids, or pyogenic granulomas.

3

A 48-year-old right-hand–dominant man comes to the office for evaluation of a tender mass of the distal volar forearm. Tinel sign is positive at the site of the mass. MRI shows that the mass involves the median nerve. Biopsy of the mass confirms a malignant peripheral nerve sheath tumor. On the basis of these findings, this diagnosis is most likely associated with which of the following conditions?

A) Amyotrophic lateral sclerosis
B) Charcot-Marie-Tooth disease
C) Multiple sclerosis
D) Neurofibromatosis 1
E) Parkinson disease

The correct response is Option D.

The correct response is that neurofibromatosis 1 (NF1) is associated with malignant peripheral nerve sheath tumors (PNSTs).

The majority of “nerve tumors” are PNSTs. Schwannomas and neurofibromas are the most common.

Malignant soft-tissue tumors of the hand are very rare and constitute only 1 to 2% of hand tumors. Malignant PNSTs have a very low annual incidence of 0.001% in the general population, and between 2 and 5% in patients with NF1. The plexiform subtype of neurofibromas poses a substantial risk of malignant degeneration.

Amyotrophic lateral sclerosis, multiple sclerosis, Charcot-Marie-Tooth disease, and Parkinson disease are not commonly associated with malignant PNSTs.

 

4

A 25-year-old man is evaluated because of a deep 6-cm, palpable mass to the mid-volar forearm. MRI is performed, but the diagnosis remains inconclusive. An initial diagnostic biopsy is planned. Which of the following is most appropriate during this procedure?

A) Avoidance of cautery
B) Leaving the biopsy site open with compressive dressings
C) Performance of an excisional biopsy
D) Placement of a skin crease transverse incision
E) Use of a tourniquet without Esmarch bandage

The correct response is Option E.

An open biopsy is done for forearm tumors that cannot be diagnosed as benign on clinical or radiographic grounds. For a large lesion, an incisional biopsy is performed to minimize the risk of surrounding surgical field tumor contamination. Wide undermining must be avoided.

The biopsy is done with a bloodless field and a tourniquet, but elevate the arm only for exsanguination without an Esmarch bandage. Obtain meticulous hemostasis before wound closure. Sutures are placed close to the wound edges to avoid additional tumor skin contamination.

While a transverse incision may provide a better cosmetic result, it may complicate limb-sparing surgery if pathology determines malignancy.

 

5

A 7-year-old girl is brought for evaluation because of a 2-month history of an asymptomatic 1-cm mass over the volar radial aspect of the wrist. The parents note no history of trauma. On physical examination, the mass is not adherent to the skin but affixed to the deeper tissues. She has full range of motion of the wrist without signs of carpal instability. X-ray studies of the wrist show no abnormalities. MRI is consistent with a ganglion. There is no evidence of carpal ligamentous injury. Which of the following is the most appropriate next step in management?

A) Observation
B) Sclerotherapy
C) Closed rupture
D) Wrist arthroscopy
E) Surgical excision

The correct response is Option A.

The next step in management is a period of observation. Although there is no general consensus regarding the best treatment for pediatric ganglions, most prefer observation and splinting for asymptomatic wrist ganglions. In the literature, the majority of pediatric wrist ganglions will spontaneously rupture and resolve without intervention. The diagnosis of volar wrist ganglion has been made by history, physical examination, and MRI, making needle biopsy unnecessary. This mass is asymptomatic and there is no sign of carpal ligamentous injury on the x-ray study or MRI, therefore there is no surgical indication for excision or wrist arthroscopy.

Closed rupture is a trauma and antiquated therapy for ganglions. Sclerotherapy does not treat wrist ganglia.

 

6

A 48-year-old woman comes for evaluation because of a 6-month history of an increasing mass on the right ring finger. She reports that a similar mass was removed from this location 2 years ago. Medical records show that the mass was solid and of a variegated tan-brown color. The pathology report identified foamy histiocytes and hemosiderin deposits. Physical examination today shows a firm, well-demarcated mass on the dorsal-ulnar aspect of the ring finger proximal phalanx. Skin is not adherent to the mass. A photograph is shown. This patient is at increased risk for which of the following?

A) Compromise of blood flow to the finger
B) Invasion of the underlying bone
C) Local recurrence or extension
D) Metastasis to the liver
E) Spread to the regional lymph nodes

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The correct response is Option C.

This is a giant cell tumor of the tendon sheath.

Ganglion cysts are the most common tumor of the hand, but are cystic in character. Giant cell tumor of the tendon sheath (also called localized nodular synovitis, fibrous xanthoma, and pigmented villonodular tenosynovitis) is the second most common tumor, but it is the most common solid tumor affecting the hand. The hemosiderin deposits give the tumor its variable tan-brown appearance.

This tumor is noted to recur locally, particularly if incompletely excised. Giant cell tumors are not known to metastasize either distantly or to regional lymphatics. Whereas giant cell tumor of bone involves the bone itself, giant cell tumor of tendon sheath does not. This tumor is not known to invade or compromise the digital vessels and thus would not compromise blood flow to the digit.

 

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7

A 55-year-old woman comes to the office because of a 2-year history of a painless mass within the thenar eminence. Physical examination shows a soft, mobile, nontender mass that does not transilluminate. Which of the following is the most likely diagnosis?

A) Epidermal cyst
B) Ganglion
C) Giant cell tumor
D) Glomus tumor
E) Lipoma

The correct response is Option E.

Lipomas are one of the most common tumors of the body with 10 to 20% occurring in the hand and wrist. Lipomas are most frequently located in the thenar eminence followed by dorsal or volar sides of the digits. The female-to-male ratio is 2:1 and age range is third to sixth decade.

Epidermal cysts have a 2:1 male-to-female ratio with a peak incidence at age 39. They are located in the distal phalanges, usually palmar index and long.

Ganglions account for 50 to 70% of all benign hand tumors with a female-to-male ratio of 3:1. They usually occur in the second to fourth decade with locations being dorsal carpal, volar carpal, volar retinacular, and mucous cyst of the distal interphalangeal joints. Some superficial ganglions will transilluminate.

Benign giant cell tumors of the tendon sheaths have no sex difference, occurring between the fourth and sixth decade and are located in the digits, mostly volar index and long.

Glomus tumors account for only 1 to 5% of hand tumors. There is a 2:1 female-to-male ratio, usually occurring between ages 30 to 50, and the tumors are subungual 50% of the time.

8

A 48-year-old man is evaluated for reconstruction after resection of a tumor of the distal radius. Physical examination shows a 10-cm defect of the metaphysis and shaft. Which of the following is the most appropriate source of bone for reconstruction?

A) Contralateral fibula
B) Contralateral radius
C) Humeral shaft
D) Medial femoral condyle
E) Osteodistraction of the ipsilateral radius

The correct response is Option A.

The preferred source of bone for such a long piece of bone reconstruction is the fibula microsurgical vascularized transfer. Another viable option, which was not listed, could be the iliac crest.

Other sources listed would not yield as much bone stock, nor would they offer sufficient bicortical bone to yield a stable reconstruction with rigid fixation, such as:

Contralateral radius (presumably with the radial vascular supply)

Humeral shaft (presumably with the posterior radial collateral vessels)

Medial femoral condyle (based on descending genicular vessels)

Thus, they would not be the preferred source, although they could all be transferred microsurgically.

Osteodistraction would not be the first line of treatment for this defect because of the length of bone transport necessary.

 

9

A 3-year-old boy is brought to the office because of a 9 × 8 × 6-cm mass of the left side of the chest. His parents report that the mass has been present for 8 months and has grown rapidly for the past 3 months. MRI confirms that the mass is calcified, lobulated, originates from the fourth and fifth ribs, and encroaches into the chest cavity to lie adjacent to the left ventricle. Other smaller lesions are identified in the scapulae, clavicles, and ribs. CT scan is shown. Examination of the specimen obtained on biopsy of the largest legion shows osteochondroma. Which of the following is the most appropriate management at this time?

A ) Radiation therapy with adjuvant chemotherapy
B ) Radical resection with adjuvant chemotherapy
C ) Wide local excision, reconstruction, and adjuvant radiation therapy
D ) Wide local excision with reconstruction
E ) No intervention at this time

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The correct response is Option D.

The lesion in the patient described is a giant calcified osteochondroma; more specifically, it is within the setting of multiple hereditary exostoses, given the multiple smaller lesions in other areas. The resected specimen is seen in the picture shown after wide local excision. 

An osteochondroma is a cartilage-covered bony growth, or exostosis, that arises from a surface of a bone – in the scenario described, the fourth and fifth ribs. It is the most common bone tumor in children, may be solitary or multiple, and may arise spontaneously or as a result of previous trauma. An osteochondroma can arise in any bone that develops from endochondral ossification. Multiple osteochondromas may be hereditary with an autosomal dominant pattern (Bessel-Hagen syndrome or hereditary multiple exostoses), as in the scenario described. Malignant transformation of an osteochondroma occurs in 1 to 25% of patients, with the risk being greater in hereditary multiple exostoses.

Numerous complications are associated with osteochondromas, including mechanical effects and deformity, fracture, vascular compromise, neurologic sequelae, and overlying bursa formation. Treatment of solitary lesions should be individualized – patients with small asymptomatic or minimally symptomatic lesions, typical imaging findings, and no functional or mechanical impairment or progressive deformity should be observed regularly for the possibility of spontaneous regression or malignant transformation. Larger, or giant, symptomatic osteochondromas should be treated by wide bony resection and reconstruction of the defect.

There is no role for neoadjuvant or adjuvant chemotherapy or radiation therapy for this lesion.

 

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10

A 26-year-old man comes to the office after jamming the index finger of his nondominant left hand while playing baseball 2 days ago. He says he has been in pain since the incident occurred. Physical examination shows a shortened, radially deviated left index finger. X-ray study shows a well-defined radiolucent lesion in the diaphysis of the proximal phalanx with a displaced apex-volar fracture. Which of the following is the most appropriate initial treatment?

A ) Amputation of the finger at the metacarpophalangeal (MCP) joint
B ) Closed reduction and percutaneous pin fixation only
C ) Curettage of the mass, bone grafting, and percutaneous pin fixation
D ) Serial x-ray studies every 3 months
E ) Wide resection of the mass and bone grafting

The correct response is Option B.

Enchondromas are benign, cartilaginous lesions that are the most common primary bone tumors arising from the bones in the hand. Approximately 35% of all enchondromas arise in the hand, and enchondromas account for as many as 90% of bone tumors seen in the hand. The proximal phalanx is the most common site of involvement, followed by the metacarpal and middle phalanx. Enchondromas may be diagnosed as an incidental finding on x-ray study. Pathologic fractures may occur. Initial treatment is to stabilize the fractures.

Amputation of the finger is not indicated with this benign lesion. Subsequent operative treatment involves curettage of the lesion with bone grafting and fixation. Small enchondromas found incidentally in x-ray study can be followed with serial x-ray. Wide resection is not indicated given the clinical course of the lesion.

 

11

A 36-year-old man comes to the office because of a 2-cm painless mass over the dorsum of the metacarpal of the index finger of the dominant right hand. A ganglion is suspected. The mass is excised with primary closure. Pathologic examination shows a high-grade epithelioid sarcoma with a single positive margin. After staging, which of the following is the most appropriate management?

A ) Aggressive curettage of the positive margin followed by high-dose adjuvant radiation therapy with no further treatment
B ) Amputation at the wrist
C ) High-dose adjuvant radiation therapy with close follow-up of the wound bed
D ) Wide local excision

The correct response is Option D.

The most common subtypes of soft-tissue sarcoma found in the hand include epithelioid sarcoma, synovial sarcoma, and malignant fibrous histiocytoma. It is not uncommon for them to be misdiagnosed initially and treated as benign tumors of the hand.

The mainstay of treatment of extremity sarcomas is wide local excision. Although preoperative and postoperative radiation therapy is often used as an adjunct to wide local excision, adjuvant radiation therapy is not an acceptable replacement for margin-free resection. Curettage is also inadequate to obtain appropriate resection margins and would, in fact, put the patient at risk for seeding of the donor wound bed with malignant cells.

Local control and survival have been shown to be comparable in patients treated with either primary amputation or limb salvage when presenting with sarcomas of the hand. Therefore, primary amputation at the wrist is virtually never indicated.

 

12

A 65-year-old man is referred for treatment of biopsy-proven subungual verrucous carcinomas of the index and long fingers of the dominant right hand. Physical examination shows deformed, raised nail beds. X-ray study shows no bony involvement of the distal phalanx with tumor. Which of the following is the most appropriate management?

A) Amputation through the distal interphalangeal joint
B) Amputation through the proximal interphalangeal joint
C) Mohs micrographic excision with graft coverage
D) Ray amputation
E) Topical application of 5-fluorouracil

The correct response is Option C.

Verrucous-type squamous cell carcinoma of the fingernails commonly affects the index, long, and ring fingers. Significant studies have shown that the etiology is related to strains of human papillomavirus (HPV).

The presence of HPV in these tumors suggests the possibility of genital-digital spread as a mechanism of tumor genesis. HPV-associated digital squamous cell carcinoma is more likely to recur following surgical treatment than previously reported. This rate of recurrence greatly exceeds that for cutaneous squamous cell carcinomas in general and may be caused by residual postsurgical HPV. Mohs micrographic excision appears to improve tumor-free excision rates compared with standard excision and may preserve more uninvolved tissue. The rate of metastasis in verrucous squamous cell carcinoma, however, appears to be low.

Because there is no evidence of bony involvement, amputation is likely premature. Amputation would be a reasonable alternative in recurrent disease or if positive margins were to continue during Mohs micrographic resection. Topical treatment with 5-fluorouracil (5-FU, Efudex) is not an adequate treatment for this lesion.

 

13

An otherwise healthy 40-year-old woman comes to the office because of an 8-month history of pain and discomfort in the ring finger of the nondominant left hand. She describes the pain as sharp and localized to the volar aspect of the distal finger. It occurs at various times during the day, including at her desk at work, and sometimes awakens her from sleep. It resolves within a few minutes regardless of position or maneuver. Physical examination shows point tenderness of the pulp of the digit. Motor and sensory examinations and an x-ray study suggest no abnormalities. Which of the following is the most appropriate next step to establish a diagnosis?

A) Allen test
B) Ice bath immersion
C) Nerve conduction studies
D) Tinel test

The correct response is Option B.

The patient described shows classic symptoms of a glomus tumor of the ring finger. Provocative tests such as cold stimulation or spraying the lesion with ethyl chloride will provoke symptoms. If this type of examination were to be negative, other tests would be recommended. However, a cold provocation test is a logical next step in the scenario described.

Glomus tumors, painful benign lesions that arise from the arteriovenous thermoregulatory glomus body, occur in the fingertip 65% of the time. Classically, they are solitary lesions from within the nail bed (50%). They also occur commonly within the soft tissues of the fingertip and present with no visible or palpable mass or discoloration, as in the scenario described. The pain tends to worsen progressively.

Nerve conduction studies are useful when the practitioner suspects either peripheral nerve compression or other peripheral nerve injury. The vignette specifically states that position is not a factor in pain relief, which would be a sign that the pain could be related to nerve compression. Also, the vignette states that motor and sensory exams of the hand are normal. Nothing above is significantly suggestive of nerve compression, and therefore nerve conduction studies is not the best answer.

The digital Allen test is appropriate when finger pain is thought to be caused by ischemia from embolic disease, thrombotic disease, vasospasm, or trauma. Nothing in the scenario described suggests these conditions.

Tinel and Phalen tests are effective provocative tests for compression neuropathies, particularly carpal tunnel. These tests are appropriate to perform in any hand examination, especially when compression neuropathy is suspected. However, this is not the best choice in the scenario described because the vignette does not suggest compression neuropathy. Negative Tinel and Phalen tests could be useful to establish a diagnosis, but only as a negative.

 

14

A 67-year-old man comes to the office because of a mass over his left palm that has grown rapidly during the past month. He reports that the mass has bled several times, although he does not recall trauma. Physical examination shows a 5 × 8-mm, lobulated, reddish purple mass. A photograph is shown. Which of the following is the most likely diagnosis?

A) Hemangioma
B) Malignant melanoma
C) Merkel cell carcinoma
D) Pyogenic granuloma
E) Squamous cell carcinoma

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The correct response is Option D.

Pyogenic granulomas are benign vascular tumors of unknown etiology. These lesions grow rapidly and can easily bleed with little or no trauma. Because of these characteristics, they are often confused with a malignancy. Although trauma is sometimes associated with these lesions, over three quarters of cases have no history of trauma or any other predisposing factor. They have also been associated with pregnancy. Their differential diagnosis includes malignancies such as basal or squamous cell carcinoma or malignant melanoma, as well as other vascular-type anomalies.

Treatment of pyogenic granulomas often consists of a shave removal and cauterization. For recurrent or large lesions, surgical excision is recommended.

Hemangiomas are benign, vascular tumors that occur in children, usually in the limbs or trunk. Despite their vascular origin, hemangiomas do not metastasize or undergo malignant transformation. With age, growth of hemangiomas will slow and in many cases regress by age 5 to 7 years.

Malignant melanomas represent one of the most aggressive forms of skin cancers. Generally, these are pigmented, although an amelanotic or melanotic variance may occur.

Merkel cell carcinomas are a rare, aggressive skin cancer usually appearing as a flesh-colored or bluish red nodule on the face, head, or neck. These appear mostly in elderly patients. Merkel cell carcinoma is of a neuroendocrine origin in the skin.

Squamous cell carcinomas are the second most frequent type of skin cancer. This type of lesion can be present on the hand, especially in patients with a history of radiation exposure. They generally present as a broad, flat lesion with the appearance of a scab. The most common areas for these are sun-exposed areas, such as the face and the back of the hand.

 

15

A 44-year-old woman comes to the office because of a 2-year history of a painless mass in the volar aspect of the forearm that has been enlarging gradually. She has no history of skin lesions or neurologic symptoms. Physical examination shows a 1.5-cm mass that is mobile in a transverse direction. Light tapping over the mass results in tingling of the index and long fingers. MRI shows a well-circumscribed area of enlargement within the median nerve that is hyperintense on T2 imaging. Which of the following is the most appropriate management?

A) En bloc resection with nerve grafting
B) Excision with nerve preservation
C) Incisional biopsy
D) Percutaneous needle biopsy
E) Segmental resection with primary nerve repair

The correct response is Option B.

The most appropriate course of treatment is excision with microsurgical nerve preservation.

Neurilemoma (schwannoma) is the most common benign nerve tumor of the upper extremity. These tumors result from a proliferation of Schwann cells. Lesions often present on the flexor surface of the hand and forearm and are generally painless; however, they may sometimes be accompanied by paresthesia. In some cases, there may be neurologic deficits. Neurilemomas are typically mobile in a transverse direction but not longitudinally. On MRI, they appear isointense with muscle on T1-weighted images but are hyperintense to subcutaneous fat on T2 imaging.

These lesions typically shell out easily from the surrounding nerve. Careful dissection with microsurgical technique is advocated to preserve nerve function. In most cases, the tumors can be removed with a small risk of neurologic deficits. Recurrence is uncommon, and there are rare instances of malignant transformation.

Neurilemomas are to be distinguished from neurofibromas, which are benign nerve tumors arising within nerve fascicles that are difficult to excise. These may be seen in the setting of neurofibromatosis. In cases where the tumor is intimately intertwined with nerve fascicles, segmental resection of involved fascicles may be necessary, followed by nerve reconstruction. There is a greater chance of neurologic dysfunction after excision of neurofibromas.

En bloc resection with nerve grafting is also not necessary for the well-circumscribed neurilemoma. In the excision of neurofibromas that are intimately associated with the nerve, if functioning fascicles need to be sacrificed, nerve grafting can be used to bridge the gap. Incisional biopsy is usually not recommended, as the lesion can instead be completely excised in a single session. Biopsy of the lesion can result in scarring, making a subsequent attempt at resection more difficult. In tumors with a high suggestion of malignancy based on imaging studies or clinical behavior (ie, severe pain and progressive neurologic deficits), biopsy may be used to obtain a tissue diagnosis.

Percutaneous needle biopsy is generally not recommended because results typically will not affect the treatment plan, and it can result in scarring of the nerve and increase the chance of damage during resection. Needle biopsy may also result in neurologic defect or pain. Segmental resection with nerve repair is generally not necessary for neurilemomas because these lesions will typically shell out easily from the surrounding nerve. In the case of neurofibromas where fascicles are intimately intertwined with the tumor, resection of involved nerve fascicles may be necessary.

 

16

52-year-old woman comes to the office because of a 9-month history of the nail deformity shown. Physical examination shows thinned skin overlying an eponychial mass. The finger is nontender to palpation. She is dissatisfied primarily by the appearance of the nail. Which of the following is the most appropriate initial step in management?

A) Excision of the mass under the eponychial fold
B) MRI of the finger
C) Nail bed reconstruction with a split toenail bed graft
D) Nail germinal matrix ablation
E) Oral administration of fluconazole for 12 weeks

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The correct response is Option A.

The most appropriate treatment of the nail groove shown is excision of the mucous cyst (ganglion) that underlies the eponychial fold and is deforming the germinal matrix. After excision of the cyst, all grooving should improve, if not resolve completely.

MRI plays a role in the identification of glomus tumors of the finger. These tumors may arise deep to the sterile nail matrix. MRI of the lesion shown might define the ganglion cyst, but is not necessary for diagnosis and would add a substantial cost to the treatment.

Nail bed reconstruction with a split sterile matrix graft can be used to address nonadherent nail plates that occur secondary to loss of the sterile matrix. The photographs shown do not demonstrate any broad, white areas of the nail plate suggestive of detachment.

Ablation of the nail germinal matrix may be necessary when split or thin nails arise following trauma to the germinal matrix. In these settings, removal of the germinal matrix with permanent loss of the nail can provide a permanent solution to the nail deformity.

Oral fluconazole is useful for treatment of onychomycosis. Nails affected by fungal infection typically present with loss of luster, discoloration, and crumbling reflective of the nail’s brittleness. None of these findings are present in the scenario described.

17

A 63-year-old woman who underwent a Mohs resection of a squamous cell carcinoma of the hand is scheduled to undergo reconstruction of a defect on her long finger. She underwent ultraviolet light treatment for eczema 54 years ago. A photograph of the defect is shown. Which of the following is the most appropriate course of action?

A) Construction of a second metacarpal artery flap
B) Full-thickness skin grafting
C) Occlusive dressing
D) Split-thickness skin grafting

Q image thumb

The correct response is Option B.

Skin cancers are the most common cancers in the world. In the United States, half of all cancers are skin cancers. Most skin cancers are thought to be related to solar exposure. Squamous cell cancers of the hand are often related to environmental agents (eg radiation or therapeutic light treatment).

If viable peritenon is available, full-thickness skin grafting is the best reconstruction option for the patient described. Healing by secondary intention in this patient would lead to a flexion contracture of the finger. In a 60-year-old patient with viable soft tissue over the tendon, a local or regional flap would not be required. Both options add another surgical procedure and have a high risk of complication and stiffness. For palmar defects, a split-thickness skin graft does not provide acceptable, durable coverage.

 

18

A 24-year-old woman comes to the emergency department after jamming her left thumb while playing basketball. An incidental finding on x-ray study of the hand is shown. Which of the following is the most likely diagnosis? 

A ) Enchondromatosis 

B ) Metachondromatosis

C ) Osteochondroma 

D ) Solitary enchondroma 

E ) Synovial chondromatosis

Q image thumb

The correct response is Option D. 

The lesion shown in the x-ray study is consistent with an enchondroma based on its classic pattern of calcifications with rings and arcs, intramedullary position, and proximal phalanx location. They may expand enough to cause endosteal scalloping of the cortex. Solitary enchondromas are the most common benign bony tumors. They have a predilection for the small bones of the hands and feet. Of these, approximately 50% are in the proximal phalanx, followed 

in frequency by the metacarpal and middle phalanx. Enchondromas account for 12 to 14% of benign bone neoplasms and 3 to 10% of osseous neoplasms in general. They occur equally in men and women. 

Solitary enchondromas are most frequently discovered in patients aged 20 to 40 years and often as incidental findings on x-ray studies, while enchondromatosis (Ollier disease) is more commonly discovered from birth to age 10 years. Metachondromatosis is a rare inherited disease associated with multiple enchondromas and osteochondromas. Osteochondroma is a cartilage-capped bony exostosis adjacent to the external surface of the bone and therefore not consistent with the x-ray study shown. Synovial chondromatosis is a rare condition where the synovial lining of a joint develops cartilage loose bodies. This does not occur within the bone. 

 

19

An 18-month-old boy is brought to the office because of a 3-month history of rapidly enlarging lesions on the long and ring fingers (shown). Examination of a specimen obtained on incisional biopsy of the lesion on the ring finger shows histology with interlacing fibroblasts and characteristic intracytoplasmic eosinophilic inclusion bodies. Which of the following is the most appropriate next step? 

A ) Administration of acyclovir 

B ) Distal finger amputations 

C ) MRI 

D ) Observation for spontaneous involution 

E ) Wide excision of both lesions with full-thickness skin grafting 

 

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The correct response is Option E. 

This is the classic appearance of infantile digital fibromatosis. Age at presentation can range from 5 months to 6 years. Lesions are rapidly growing, broad-based masses on the dorsal or lateral aspects of fingers. They have classic intracytoplasmic inclusion bodies in cellular tumors. They may be multiple with characteristic €œkissing € lesions. 

Recommended treatment is complete wide excision and reconstruction, often with full-thickness skin grafting or coverage with a local flap. Inadequate resection leads to recurrence. 

Acyclovir would be appropriate for herpetic whitlow, but not for this condition. It is inappropriate for children younger than 2 years. Safety and efficacy in children younger than 2 years have not been established. 

Distal finger amputation is overly aggressive and unnecessary for this condition. 

Despite the possibility of spontaneous regression in some cases, these tumors may cause finger deformities if observed and must be distinguished from fibrosarcoma. MRI is not helpful in distinguishing any better the extent of the tumor. 

 

20

A 45-year-old man comes to the office because of a 6-month history of a painless mass on the right distal forearm. Physical examination shows a well-circumscribed 6-cm mass. MRI of the chest, axilla, and forearm shows no other lesions. Examination of a specimen obtained on incisional biopsy shows epithelioid sarcoma. Which of the following is the most appropriate initial management?

A ) Chemotherapy

B ) Excisional biopsy

C ) Forearm amputation 

D ) Radiation therapy

E ) Wide local excision 

 

The correct response is Option D. 

Preoperative radiation should be administered for epithelioid sarcomas, as it will help decrease tumor size and local recurrence rates. Chemotherapy is appropriate for tumors that are high grade, greater than 10 cm in diameter, involve the lymph node, or are metastatic. As chemotherapy plays an important role in epithelioid sarcomas, it is usually given postoperatively. Excisional biopsy is reserved for low-grade tumors. Epithelioid sarcomas are usually high grade, so excisional biopsy would not be appropriate. Forearm amputation should be considered if negative margins cannot be achieved. Wide excision with negative margins is a mainstay of surgical treatment.

21

A 45-year-old man comes to the office because he has had a two-week history of persistent pain in the small finger after bumping it against a table. Radiographs are shown. Which of the following percentages best describes the likelihood of tumor recurrence after curettage and bone grafting in this patient?

A ) 10 B ) 25 C ) 50 D ) 75 E ) 90

Q image thumb

The correct response is Option A.

The lesion represents an enchondroma, which is the most commonly found primary bone tumor in the hand. This benign tumor is thought to develop from fragments of cartilage near the central physis. The tumor is most common in the proximal phalanx, followed by the metacarpals and middle phalanx. Patients often present with finger pain following minor trauma that has resulted in the development of a pathologic fracture. Radiographically, enchondromas appear as well-defined areas of central lucency in the metaphyseal or diaphyseal portion of the bone. As the enchondroma grows, it frequently results in thinning and scalloping of the bone €™s cortex. Stippling and punctate calcifications may be seen within the areas of lucency.

The treatment for patients presenting with a pathologic fracture within an area involved with an enchondroma usually begins with a period of immobilization to allow for fracture healing; this may then be followed by surgery, most commonly open biopsy, curettage, and bone grafting. Recurrence following curettage is infrequent but occurs in 2% to 15% of patients. Because of this, patients should have periodic radiographic screening after surgery at six months, one year, and two years after initial surgery.

22

A 45-year-old woman is evaluated for a two-year history of a slowly enlarging soft-tissue tumor of the right volar palm at the level of the distal palmar crease and the fourth metacarpophalangeal joint. Findings on MRI are highly suggestive of a soft-tissue malignancy. Which of the following is the most appropriate management?

A ) Excisional biopsy through a Brunner incision

B ) Incisional biopsy through a longitudinal incision

C ) Needle aspiration and touch preparation of specimen

D ) Preoperative chemotherapy followed by wide local excision

E ) Wide local excision followed by radiation therapy
 

The correct response is Option B.

The biopsy is the most important aspect of the evaluation of any hand tumor. The biopsy must be planned properly so that it does not make adequate wide local resection more difficult or impossible. The biopsy incision must be incorporated within the definitive resection; therefore, transverse or Brunner incisions would spread the tumor away from the primary, which could increase the incidence of local recurrence or prevent limb-preserving surgery.

In the scenario described, the scar should be parallel to the metacarpal, allowing it to be easily removed within the resection margins. One study suggested that ultimate survival may be compromised when the biopsy is performed at an institution other than the one providing definitive treatment.

MRI is the imaging technique of choice for evaluating soft-tissue neoplasm. In one study of 134 palpable masses in the hand, MRI demonstrated the cause of the masses in 94% of the cases. Despite the helpful information shown by MRI, soft-tissue biopsy is still mandatory to determine a definitive treatment plan.

Needle aspiration and touch preparation is not appropriate for soft-tissue malignancy of the hand. More substantial tissue is needed to evaluate potential sarcomas. Favorable results have been reported using core needle biopsy.

Wide local excision followed by radiation therapy and preoperative chemotherapy followed by wide local excision are not appropriate because definitive tissue biopsy is needed before radical surgery and chemotherapy are undertaken.

23

A 57-year-old man has a painless mass on the right wrist that has been enlarging gradually over the past two years. Physical examination shows a 4-cm mass at the wrist level deep to the flexor carpi ulnaris. The mass is smooth and firm, is nonadherent to surrounding structures, and is not bony. Tinel sign is present at the site of the mass, but no ulnar nerve sensory or motor deficits are noted. Plain-film radiographs show no abnormalities. MRI shows a homogeneous mass within the ulnar nerve. Which of the following is the most likely diagnosis?

(A) Aneurysm of the ulnar artery

(B) Enchondroma

(C) Epidermal inclusion cyst

(D) Giant cell tumor of the tendon sheath

(E) Schwannoma

The correct response is Option E.

The most likely pathology of this mass is a schwannoma of the ulnar nerve. These benign nerve tumors are typically painless proximal to the wrist. Schwannomas of the digits tend to be painful. A Tinel sign can often be demonstrated. Nerve function typically is not disturbed. Because of the size and location, MRI is effective in characterizing and localizing the mass. With magnification, marginal excision of schwannomas is easily performed because they are almost self-extruding from the nerve. Compared with neurofibromas, schwannomas are noninfiltrative. The recurrence rate is approximately 4%. The risk of nerve deficit is higher for excision after recurrence.

An aneurysm of the ulnar artery presents as a pulsatile mass. Vasospastic or thromboembolic findings may be present. The ulnar nerve may be compressed by the aneurysm. Surgery will preclude thromboembolic events. If the digital brachial index is <0.7, arterial reconstruction is required.

An epidermal inclusion cyst results from implantation of epithelial cells into the underlying soft tissue or bone after an injury. Involvement of the thumb or index finger is most common. The cyst can abscess and require drainage. Otherwise, the cyst can be marginally excised from surrounding soft tissue or curettaged from bone. Interestingly, imaging of bony involvement can demonstrate cortical erosion or bone destruction that is more typical for malignancy.

A giant cell tumor of the tendon sheath is a rubbery mass that is more common along the flexor surfaces of the digits. The slowly enlarging tumor can compress or splay adjacent digital nerves and arteries. Recurrence is minimized with a complete marginal excision and bipolar cauterization of the tumor bed. The recurrence rate is reported to be 5% to 50%.

24

A 37-year-old woman has had intermittent pain in the tip of the long finger of the dominant right hand during the past three years. She says the pain is excruciating and occurs randomly. She has extreme sensitivity to cold in the finger. Physical examination shows extreme tenderness of the central matrix of the long finger. Loupe magnification of the nail complex and finger pad shows no abnormalities. Which of the following is the most likely diagnosis?

(A) Buerger disease

(B) Epidermal inclusion cyst

(C) Glomus tumor

(D) Hemangiopericytoma

(E) Kaposi sarcoma

The correct response is Option C.

Glomus tumors occur most frequently in the fingertip. In the digit, most glomus tumors occur subungually. The digital pulp is a less common location. Symptoms of glomus tumors typically include pain, sensitivity to cold, and tenderness on palpation. On close evaluation, a blue €‘purple mass can sometimes be observed. The Love sign is extreme pain on direct, focal pressure. The Hildreth sign is ablation of pain with proximal tourniquet inflation. MRI can localize the glomus tumor.

The surgical approach is either direct transungual or lateral subperiosteal. Complete excision results in rapid resolution of symptoms. Recurrence varies from 6.6% to 33%. Incidence of nail deformity with the transungual approach is 3.3% to 10%.

Buerger disease or thromboangiitis obliterans (TAO) is an inflammatory, occlusive, and nonatherosclerotic vascular disease. The angiitis most commonly affects the small and medium €‘sized arteries, veins, and nerves. Tobacco use and development and progression of TAO are clearly linked. The precise etiology of TAO is unknown. The arteriographic findings include normal proximal arteries, absent atherosclerosis or emboli, and focal and multifocal distal segmental occlusions of small and medium €‘sized vessels, interspersed with normal €‘appearing segments. Irregular stenosis with corkscrew appearance is the classic arteriographic finding. Cessation of tobacco use is the critical first step in successful treatment.

An epidermal inclusion cyst develops after an injury traps epithelial cells in the underlying soft tissue or bone. These cysts slowly enlarge and typically are not painful. However, an epidermal inclusion cyst can abscess and require drainage.

Hemangiopericytoma is a rare tumor that can involve soft tissue or bone. Approximately 30% to 50% of cases develop in the limbs. It derives from vascular Zimmermann pericytes. These differ from glomus tumor and hemangioma. Biopsy is critical to diagnosis, and treatment involves functional wide local excision. The tumor can recur locally, and malignant forms can metastasize, primarily to the lung and skeleton.

There are several clinical types of Kaposi sarcoma (KS). Classic KS runs an indolent course over 10 to 15 years. Most cases are seen in elderly men of Italian or Eastern European Jewish ancestry. However, HIV-associated KS has a fulminant, disseminated, and most often fatal course. Other clinical forms of KS occur in recipients of renal allotransplantation, patients undergoing immunosuppressive therapy, prepubescent children, or young black African men. Recently, a gamma herpes virus €”human herpes virus type 8 (HHV-8) €”was identified in KS tissue from patients with classic, African, transplantation-related, and AIDS-associated KS.

 

25

A 57-year-old man has a painless mass on the right wrist that has been enlarging gradually over the past two years. Physical examination shows a 4-cm mass at the wrist level deep to the flexor carpi ulnaris. The mass is smooth and firm, is nonadherent to surrounding structures, and is not bony. Tinel sign is present at the site of the mass, but no ulnar nerve sensory or motor deficits are noted. Plain-film radiographs show no abnormalities. MRI shows a homogeneous mass within the ulnar nerve. Which of the following is the most likely diagnosis?

(A) Aneurysm of the ulnar artery

(B) Enchondroma

(C) Epidermal inclusion cyst

(D) Giant cell tumor of the tendon sheath

(E) Schwannoma

 

The correct response is Option E.

The most likely pathology of this mass is a schwannoma of the ulnar nerve. These benign nerve tumors are typically painless proximal to the wrist. Schwannomas of the digits tend to be painful. A Tinel sign can often be demonstrated. Nerve function typically is not disturbed. Because of the size and location, MRI is effective in characterizing and localizing the mass. With magnification, marginal excision of schwannomas is easily performed because they are almost self-extruding from the nerve. Compared with neurofibromas, schwannomas are noninfiltrative. The recurrence rate is approximately 4%. The risk of nerve deficit is higher for excision after recurrence.

An aneurysm of the ulnar artery presents as a pulsatile mass. Vasospastic or thromboembolic findings may be present. The ulnar nerve may be compressed by the aneurysm. Surgery will preclude thromboembolic events. If the digital brachial index is <0.7, arterial reconstruction is required.

An epidermal inclusion cyst results from implantation of epithelial cells into the underlying soft tissue or bone after an injury. Involvement of the thumb or index finger is most common. The cyst can abscess and require drainage. Otherwise, the cyst can be marginally excised from surrounding soft tissue or curettaged from bone. Interestingly, imaging of bony involvement can demonstrate cortical erosion or bone destruction that is more typical for malignancy.

A giant cell tumor of the tendon sheath is a rubbery mass that is more common along the flexor surfaces of the digits. The slowly enlarging tumor can compress or splay adjacent digital nerves and arteries. Recurrence is minimized with a complete marginal excision and bipolar cauterization of the tumor bed. The recurrence rate is reported to be 5% to 50%.

 

26

A 37-year-old woman has had intermittent pain in the tip of the long finger of the dominant right hand during the past three years. She says the pain is excruciating and occurs randomly. She has extreme sensitivity to cold in the finger. Physical examination shows extreme tenderness of the central matrix of the long finger. Loupe magnification of the nail complex and finger pad shows no abnormalities. Which of the following is the most likely diagnosis?

(A) Buerger disease

(B) Epidermal inclusion cyst

(C) Glomus tumor

(D) Hemangiopericytoma

(E) Kaposi sarcoma

The correct response is Option C.

Glomus tumors occur most frequently in the fingertip. In the digit, most glomus tumors occur subungually. The digital pulp is a less common location. Symptoms of glomus tumors typically include pain, sensitivity to cold, and tenderness on palpation. On close evaluation, a blue €‘purple mass can sometimes be observed. The Love sign is extreme pain on direct, focal pressure. The Hildreth sign is ablation of pain with proximal tourniquet inflation. MRI can localize the glomus tumor.

The surgical approach is either direct transungual or lateral subperiosteal. Complete excision results in rapid resolution of symptoms. Recurrence varies from 6.6% to 33%. Incidence of nail deformity with the transungual approach is 3.3% to 10%.

Buerger disease or thromboangiitis obliterans (TAO) is an inflammatory, occlusive, and nonatherosclerotic vascular disease. The angiitis most commonly affects the small and medium €‘sized arteries, veins, and nerves. Tobacco use and development and progression of TAO are clearly linked. The precise etiology of TAO is unknown. The arteriographic findings include normal proximal arteries, absent atherosclerosis or emboli, and focal and multifocal distal segmental occlusions of small and medium €‘sized vessels, interspersed with normal €‘appearing segments. Irregular stenosis with corkscrew appearance is the classic arteriographic finding. Cessation of tobacco use is the critical first step in successful treatment.

An epidermal inclusion cyst develops after an injury traps epithelial cells in the underlying soft tissue or bone. These cysts slowly enlarge and typically are not painful. However, an epidermal inclusion cyst can abscess and require drainage.

Hemangiopericytoma is a rare tumor that can involve soft tissue or bone. Approximately 30% to 50% of cases develop in the limbs. It derives from vascular Zimmermann pericytes. These differ from glomus tumor and hemangioma. Biopsy is critical to diagnosis, and treatment involves functional wide local excision. The tumor can recur locally, and malignant forms can metastasize, primarily to the lung and skeleton.

There are several clinical types of Kaposi sarcoma (KS). Classic KS runs an indolent course over 10 to 15 years. Most cases are seen in elderly men of Italian or Eastern European Jewish ancestry. However, HIV-associated KS has a fulminant, disseminated, and most often fatal course. Other clinical forms of KS occur in recipients of renal allotransplantation, patients undergoing immunosuppressive therapy, prepubescent children, or young black African men. Recently, a gamma herpes virus €”human herpes virus type 8 (HHV-8) €”was identified in KS tissue from patients with classic, African, transplantation-related, and AIDS-associated KS.

 

27

A 26-year-old woman comes to the office for consultation regarding a painful mass in the right palm that has been enlarging over the past three years. She has had paresthesia of the hand and weakness of the thumb during this time. Gadolinium-enhanced MRI (shown) shows a high-flow arteriovenous malformation involving the thenar muscles, supplied mostly by the radial artery, and extending to the first and second metacarpals. Which of the following is the most appropriate initial management?
(A) Pulsed-dye laser therapy
(B) Ligation of the radial artery
(C) Embolization of the radial artery 
(D) Selective intralesional embolization 
(E) Surgical resection 
 

Q image thumb

The correct response is Option D.

This patient must be counseled that any surgical intervention could devascularize her hand or digits, due to postoperative vasospasm of the abnormal digital arteries. Ligation of the radial artery may result in transiently decreased flow to the arteriovenous malformation (AVM), but this lesion will almost certainly develop collaterals from the ulnar system and remain symptomatic. Surgical resection alone, even with the use of a tourniquet, may be technically very difficult with significant risk of injury to digital vessels or nerves. Selective embolization of the lesion, which is performed by an interventional radiologist, creates a window of opportunity for staged surgical resection, due to decreased flow to the AVM. Selective preoperative embolization may, in fact, be performed several times prior to surgical resection, for a complex or large AVM. Pulsed-dye laser therapy would not be helpful for deep, high-flow vascular malformations.

Preoperative photographs are shown below.

A image thumb
28

A 30-year-old man is brought to the operating room for removal of a grade 2 fibrosarcoma on the right hand. He is otherwise healthy and currently takes no medications. Physical examination shows a 4 x 5-cm lesion on the dorsal aspect of the hand. Which of the following interventions is the most appropriate preparation for dissection of the lesion?
(A) Elevation of the arm for one minute and application of tourniquet pressure to 250 mmHg
(B) Exsanguination with an elastic bandage and application of tourniquet pressure to 200 mmHg
(C) Exsanguination with an elastic bandage and application of tourniquet pressure to 250 mmHg 
(D) Compression of the brachial artery, elevation of the arm for one minute, and application of tourniquet pressure to 250 mmHg 
(E) Compression of the radial and ulnar arteries, elevation of the arm for one minute, and application of tourniquet pressure to 250 mmHg 
 

The correct response is Option D.

Exsanguination of the arm in patients with neoplastic tumors is not recommended due to the possibility of dissemination of tumor cells to other sites. The arm may be partially exsanguinated through elevation and compression of the brachial artery above the elbow for one minute. The tourniquet may then be inflated so dissection can proceed in a relatively bloodless field. Elevation of the arm alone has been found to be the least effective mechanism of exsanguination.

Tourniquet pressures have been shown to be adequate for dissection when they are approximately 50 to 75 mmHg greater than systolic pressure. Unnecessarily high tourniquet pressures may result in nerve injury and post-tourniquet paralysis. As a general rule in adults, most procedures can be performed with tourniquet pressures of 250 mmHg. In obese patients or in patients with significant hypertension or atherosclerotic disease, this may need to be increased to 300 mmHg. In this young patient, a pressure of 250 mmHg would suffice for surgery.

29

A 20-year-old woman who is a competitive gymnast comes to the office for evaluation of a soft, subcutaneous mass on the volar-radial aspect of the right wrist (shown). She says the mass fluctuated in size until one month ago; since then, the mass has remained persistently prominent and associated with achy, intermittent discomfort in the wrist. Which of the following interventions is most likely to result in the lowest risk of recurrence of the mass?
(A) Rupture
(B) Injection
(C) Aspiration
(D) Incision
(E) Excision
 

Q image thumb

The correct response is Option E.

This patient has a ganglion, the most common soft-tissue tumor of the hand, which is prevalent in women between the second and fourth decades of life. Volar wrist ganglia usually arise from either the radiocarpal joint or the capsule of the scaphotrapezial joint and are the second most common ganglion of the hand, representing approximately 20%; dorsal wrist ganglia account for 60% to 70% of hand and wrist ganglia and most often originate at the scapholunate ligament. Treatments are categorized as nonoperative and operative. The lowest recurrence rates are associated with complete surgical excision of the ganglion.

Nonoperative treatments include needle decompression or aspiration, rupture by digital pressure or other blunt external force (striking the mass with a large book, for example), and injection with corticosteroids, sclerosing agents, local anesthetics, or combinations of these solutions. These techniques may reduce the mass and alleviate symptoms with limited success for varying periods of time but are associated with higher rates of recurrence than surgical excision.
 

30

A 70-year-old woman comes to the office for evaluation of a painless mass on the left ring finger involving the perionychium (shown) that has been enlarging rapidly over the past three weeks. She says that minor trauma causes the mass to bleed. Physical examination shows a fleshy, reddish, superficially purulent rash. Which of the following is the most likely diagnosis?
(A) Basal cell carcinoma
(B) Hemangioma 
(C) Keratoacanthoma
(D) Pyogenic granuloma
(E) Squamous cell carcinoma
 

Q image thumb

The correct answer is Option D.

Pyogenic granuloma is a reactive vascular tumor that rapidly grows in response to minor trauma. These tumors are somewhat friable and bleed easily. Treatment is usually excision with cauterization of the base. As with any tumor, pathology should be obtained to rule out less common tumors. Management options include chemical cauterization, curettage and cauterization, and formal excision.

Squamous cell carcinoma is not likely in view of the fact that the tumor arose within a three-week time period. Basal cell carcinoma is also unlikely because these are generally more erosive-appearing lesions that require a longer time interval than three weeks to develop to the size shown. Keratoacanthoma is also unlikely because these are keratotic-appearing lesions that usually have a central pore. Although these rapidly proliferate, they are not generally as friable or have the characteristic of easy bleeding. Keratoacanthomas are also sessile appearing. Hemangioma is also incorrect because a hemangioma developing in an elderly patient is unusual. Hemangioma should be included in the differential diagnosis of a rapidly proliferating vascular lesion in the neonatal period.

31

A 63-year-old man who has been hospitalized for the past week after undergoing coronary artery bypass grafting has a pulsatile mass in the volar aspect of the right wrist. The nurse reports that an arterial catheter was recently removed from the radial artery. Which of the following is the most appropriate management of the mass?


(A) MRI of the wrist
(B) Application of a pressure dressing until the mass resolves
(C) Anticoagulation
(D) Replacement of the radial artery catheter
(E) Exploration and vascular repair
 

The correct response is Option E.

False or pseudoaneurysms result from an arterial wall penetration. The extravasated hematoma organizes and then recanalizes. The lumen of the false aneurysm will have endothelial lining. False aneurysms result from penetrating injuries and fractures, such as stab wounds, arterial catheterization fractures, or gunshot wounds. The treatment of a pseudoaneurysm is dependent on whether the radial artery is critical to hand perfusion. If the ulnar artery alone is adequate, the aneurysm can be ligated and excised. If the radial artery is critical to distal perfusion, the radial artery can be either directly repaired or reconstructed with a vein graft. Usually, the arterial defect is too large for primary repair of the artery. If the site becomes infected, the risk for arterial hemorrhage is significant.

True aneurysms occur after an injury that allows the vessel to gradually dilate. The true aneurysm is more uniform in shape and has an endothelial lining. True aneurysms result from repeated trauma (i.e., hypothenar hammer syndrome) or vessel diseases that weaken the wall. 

MRI would provide detailed imaging of the lesion; Doppler ultrasonography would provide similar information more quickly. In an adult, compressive dressing can control bleeding but is not successful long term in resolving the pseudoaneurysm. One case in a child has been reported using ultrasound-directed compression. Anticoagulation would complicate bleeding from the pseudoaneurysm. Replacement of an arterial catheter could aggravate bleeding, compromise distal flow, or increase infection risk.
 

32

A 30-year-old man has pain in the right wrist after falling on his outstretched right hand. Radiographs of the wrist show normal findings; a radiograph of the hand is shown above. Which of the following is the most likely diagnosis?

(A) Chondromyxoid fibroma
(B) Enchondroma
(C) Giant cell tumor
(D) Osteoid osteoma
(E) Osteosarcoma

Q image thumb

The correct response is Option B.

The most likely diagnosis is enchondroma, a benign cartilaginous tumor that is the most common primary tumor of bone in the hand. Enchondromas typically develop during the second or third decade of life. Although they are often asymptomatic and discovered incidentally on imaging studies, as in this patient, pathologic fractures occurring in the 
area of the tumor may lead to diagnosis. Pain in the absence of fracture is suggestive of malignant degeneration.
In patients with enchondromas, radiographs show a scalloped, lytic lesion within the medullary canal of the affected bone, occasionally with scattered calcification. Periosteal reaction is rare. Microscopic examination shows benign clusters of hyaline cartilage surrounded by lamellar bone with varying calcification.

Enchondromas that develop on the surface of the bone or within the cortex are known as periosteal or juxtacortical chondromas. Conditions associated with enchondroma include Ollier disease, or multiple enchondromatosis, and Maffucci syndrome, in which patients have multiple enchondromas associated with subcutaneous hemangiomas. 
Appropriate management is curettage of the lesion. Bone grafting or use of a bone substitute may be required.

Chondromyxoid fibromas are benign cartilaginous tumors that rarely occur in the upper extremity. Radiographs show a radiolucent lesion with small sclerotic rims that separate the tumor from lamellar bone.

Giant cell tumors of bone are not common in the hand, wrist, or distal forearm. Only 2% to 5% of all giant cell tumors of bone occur in the hand; in contrast, the radius is the third most commonly affected site, with 16% of all giant cell tumors of bone occurring in this region. Management is controversial, as limited resection is associated with high recurrence rates locally, and more aggressive resection is likely to result in significant limitation of function.

Osteoid osteomas are symptomatic lesions. Affected patients have pain, especially at night, that is relieved with administration of nonsteroidal anti-inflammatory agents. Radiographs show a target-like lesion, illustrating the central nidus of the tumor within the bone.

Osteosarcomas are also rare in the hand. These malignant tumors exhibit varying degrees of bone erosion and periosteal reaction.

33

A 67-year-old man has a mass overlying the metacarpal of the right index finger that has enlarged rapidly over the past six weeks. He underwent kidney transplantation for polycystic renal disease five years ago. Which of the following is the most appropriate management?

(A) Observation for spontaneous involution
(B) Electrodesiccation and curettage
(C) Interlesional injection of 5-fluorouracil
(D) Excisional biopsy and primary wound closure
(E) Excision and sentinel node biopsy

The correct response is Option D.

This 67-year-old man has a keratoacanthoma, a cutaneous lesion that appears similar to squamous cell carcinoma. Although keratoacanthomas had been thought previously to be benign, recent studies have suggested that this lesion 
is actually a variant of squamous cell carcinoma. Keratoacanthoma first appears as a red papule on sun-damaged skin and expands rapidly over several weeks. Although most keratoacanthomas regress even without treatment, some can be aggressive and metastasize. Because these lesions have shown an affinity for immunosuppressed patients, an association has been suggested.

Excisional biopsy is most appropriate because the architecture of the lesion is important for accurate diagnosis. In this patient who has a keratoacanthoma affecting the right index finger, the wound can be closed primarily.

Observation for spontaneous involution is obviously inadequate and even dangerous in an immunocompromised patient with a keratoacanthoma because of the risk for aggressive tumor growth and metastasis.

Electrodesiccation and curettage and interlesional injection of 5-fluorouracil are not appropriate therapy in immunocompromised patients.

Sentinel node biopsy is excessive because the risk for lymphatic spread is low.

34

A 60-year-old man has a 2.2 * 1.5-cm squamous cell carcinoma of the right lower lip with paresthesia in the distribution of the right mental nerve. A 1-cm lymph node can be palpated in the ipsilateral neck. There are no distant metastases. According to TNM classification, which of the following is the correct clinical classification of this patient's tumor?

(A) T2 N0 M0
(B) T2 N1 M0
(C) T3 N0 M0
(D) T4 N1 M0
(E) T4 N1 M1

The correct response is Option D.

The staging of squamous cell carcinomas of the lip involves three descriptors: T, N, and M. The T descriptor is based on the diameter or surface area of the tumor. The N descriptor describes nodal status. The M descriptor indicates distance of metastasis beyond the neck. This staging criteria allows physicians to predict patient outcomes and to choose appropriate therapy based on comparisons with patients in large studies.

In this patient who has a 2.2 * 1.5-cm squamous cell carcinoma of the right lower lip with involvement of one lymph node only, the tumor is correctly classified as T4 N1 M0. Although the tumor can be classified as T2 based on size alone, any tumor that involves infiltration of skeletal muscle, nerve, cartilage, or bone (ie, extradermal structures) is classified as T4. Metastasis to one regional lymph node is N1, and absence of distant metastases is M0. Any T4 lesion is classified as Stage IV; a tumor with lesser T classification combined with an N1 would be designated as Stage III.

A TNM classification table is shown below.

35

Chronic exposure to which of the following substances is associated with the development of squamous cell carcinoma of the nasal sinus cavity?

(A) Alcohol
(B) Asbestos
(C) Benzene
(D) Nickel
(E) Tobacco

The correct response is Option D.

Chronic exposure to nickel has been shown to be associated with the development of squamous cell carcinoma of the nasal sinuses. This is the most common malignancy of the sinonasal tract, affecting the maxillary sinus most frequently, followed by the nasal sinus cavity, ethmoid sinus, and sphenoid sinus. In one study, workers at a nickel refinery in Norway developed squamous cell carcinoma at 250 times the expected rate, with a latent period varying from 18 to 36 years.

Exposure to alcohol and tobacco has been associated with squamous cell carcinoma of the upper aerodigestive tract, not the sinonasal tract. Exposure to asbestos has been shown to increase the risk for development of pleural mesothelioma, and benzene exposure is associated with the development of hemopoietic malignancies.

 

36

A 38-year-old woman has onset of gustatory sweating and flushing of the left cheek one year after undergoing superficial parotidectomy on the left for removal of a parotid tumor. The most likely cause of her current symptoms is dysfunction of which of the following nerves?

(A) Auriculotemporal
(B) Chorda tympani
(C) Facial
(D) Infraalveolar
(E) Lingual

The correct response is Option A.

This 38-year-old woman with gustatory sweating has findings consistent with Frey syndrome, a condition that occurs in more than 50% of patients who have undergone parotidectomy. Frey syndrome is thought to be caused by the development of anastomoses between postganglionic parasympathetic fibers from the otic ganglion, which are carried by the auriculotemporal nerve, and postganglionic sympathetic fibers in the sweat glands that lie within the vascular plexus of the skin. The fibers of both systems are cholinergic and mediated by acetylcholine.

The Minor starch-iodine test can be used to establish a diagnosis of Frey syndrome in symptomatic patients. In this test, 10% povidone-iodine is applied to the cheek, allowed to dry, and covered with cornstarch. Following the administration of a lemon drop stimulus, a region of blue discoloration will elicit the location of the gustatory sweating. Intracutaneous botulinum toxin, which relieves the hyperhidrosis and flushing associated with Frey syndrome by blocking neurotransmission of acetylcholine, can be administered to confirm the diagnosis. Although one series of botulinum toxin injections may result in relief of symptoms for as long as one year, repeat injections are frequently required.

Appropriate operative management is direct excision of involved skin and interposition of any one of a number of autologous tissues, including sternocleidomastoid muscle, fascia lata, lyophilized human dura, a SMAS flap, or a dermal graft between the skin and the parotid gland. Human preserved dermal allograft has been used recently with some success for interposition grafting.

The chorda tympani mediates taste sensation to the anterior two-thirds of the tongue via the facial (VII) nerve, which innervates the muscles of facial expression. The infraalveolar nerve provides sensation to the teeth, while the lingual nerve provides sensation to the tongue.

 

37

What is the approximate incidence of metachronous carcinoma in patients with squamous cell carcinoma of the head and neck who continue to smoke cigarettes?

(A) 5%
(B) 10%
(C) 20%
(D) 40%
(E) 60%

 

The correct response is Option D.

In patients who have been previously diagnosed with squamous cell carcinoma but who continue to smoke, the incidence of metachronous carcinoma is 30% to 40%. In contrast, patients diagnosed with squamous cell carcinoma who stop smoking have only a 6% risk for development of metachronous carcinoma. The prevalence of metachronous carcinoma in all patients who have squamous cell carcinomas affecting a second site, regardless of smoking history and/or continued exposure to tobacco, is reported as 14.2%. The incidence of synchronous carcinomas has been reported as 5% to 7%. Further studies of tumor biology will continue to delineate the effects of carcinogens such as tobacco on the mucosal surfaces of the upper aerodigestive tract.

 

38

In a 58-year-old man undergoing total parotidectomy, which of the following is the most appropriate technique to safely identify the facial nerve trunk?

(A) Identifying the temporal branches of the nerve and performing a retrograde dissection
(B) Using the midpoint between the fascial covering of the parotid gland and the earlobe as a landmark
(C) Using the plane between the superficial and deep lobes of the parotid gland as a landmark
(D) Using the tympanomastoid suture as a landmark
(E) Using a nerve stimulator

 

The correct response is Option D.

The safest and most convenient way to identify the facial nerve trunk during a parotidectomy procedure involves the use of the tympanomastoid suture as a landmark. This structure is defined as the suture line located between the posterior bony auditory canal and the mastoid portion of the temporal bone. The facial nerve can be found at a point 6 mm to 8 mm below the inferior end of the tympanomastoid suture line. If the region of the suture line is carefully dissected (ie, with a fine hemostat) in the direction of the facial nerve, the soft tissues can then be separated to reveal the glistening, white facial nerve.
Identification and dissection of the temporal branches of the facial nerve is a difficult, dangerous procedure; tagging of the distal branches is instead more reliable. With this technique, the surgeon identifies the marginal mandibular nerve as it crosses the facial vein and then performs a retrograde dissection to the nerve trunk.

Because the earlobe is not a fixed point, it cannot be used as a landmark. A tragal pointer, which is defined as the cartilaginous portion of the external auditory canal at its bony junction with the skull, is used instead. The facial nerve can be found within 5 mm from this point as it exits the stylomastoid foramen.

The plane between the superficial and deep lobes of the parotid gland is obscure; a proximal approach is safer and more effective.

Nerve stimulators are used as aids and are not the primary means for identifying the nerve trunk.

 

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A 46-year-old man undergoes excision of a 1-cm cyst on the right cheek that is thought to be an epidermal inclusion cyst. Histologic examination of a biopsy specimen shows pleomorphic adenoma. Which of the following is the most appropriate management?

(A) Observation
(B) Reexcision of the lesion
(C) Superficial parotidectomy
(D) Superficial parotidectomy and selective lymph node dissection
(E) Total parotidectomy

The correct response is Option C.

Pleomorphic adenoma is most appropriately managed with superficial parotidectomy. A pleomorphic adenoma is an isolated, firm, round tumor surrounded by a delicate capsule. It is the most common benign tumor of the salivary glands and is rarely associated with malignant transformation. Approximately 90% of pleomorphic adenomas affecting the parotid gland lie superficial to the facial nerve.

Because pleomorphic adenomas are characterized by microscopic extension of tumor through the capsule, and thus associated with a multifocal pattern of recurrence, superficial parotidectomy with preservation of the facial nerve is indicated. 

Observation and/or simple reexcision are inadequate management and are likely to result in recurrence. Lymph node dissection is an unnecessary, excessive procedure in a patient with a benign tumor. Total parotidectomy is also excessive and can lead to serious morbidity resulting from injury or sacrifice of the facial nerve.

 

40

A 42-year-old woman develops gustatory sweating in the parotid region six months after undergoing parotidectomy for removal of a benign mixed tumor. The most likely cause of this complication is abnormal regeneration of which of the following nerves?

(A) Auriculotemporal
(B) Chorda tympani
(C) Facial
(D) Great auricular
(E) Lingual

 

The correct response is Option A.

Gustatory sweating that develops following parotidectomy is known as Frey's syndrome or auriculotemporal syndrome and results from abnormal regeneration of auriculotemporal nerve fibers to sweat glands within the skin. Placement of thin surgical flaps over the parotid gland has been shown to exacerbate this condition; interposition of a submuscular aponeurotic system (SMAS) flap between the parotid bed and overlying skin may lead to improvement. The diagnosis can be confirmed by placing a single-ply facial tissue on the skin overlying the parotid gland; damp patches will be seen in areas affected by gustatory sweating. The Minor starch-iodine test, which involves placement of a 1 ( 1-cm test tape (containing iodine and starch) on the affected area, can be used to determine the total number of damp patches and thus confirm the distribution of the diaphoresis.

Although skin excision alone can successfully treat Frey's syndrome, tympanic neurectomy may be required. Systemic administration of anticholinergic agents results in abatement of symptoms but is associated with adverse effects and thus not recommended by many physicians. Topical glycopyrrolate (Robinul) or diphemanil methyl sulfate (Prantal) can be applied to the affected area to control gustatory sweating. When the diaphoresis has subsided, topical 20% aluminum chloride in alcohol (Drysol) should be applied once daily.

 

41

A 38-year-old woman has a 2.5-cm squamous cell carcinoma of the tongue. On examination, she has one mobile 2-cm homolateral palpable lymph node; there are no distant metastases. Which of the following is the most appropriate classification of this patient's tumor?

(A) T1 N0 M1
(B) T1 N1 M0
(C) T2 N1 M0
(D) T2 N2 M0
(E) T3 N2 M1

The correct response is Option C.

In this patient who has a 2.5-cm squamous cell carcinoma of the tongue with involvement of one lymph node only, the tumor is correctly classified as T2 N1 M0. The staging of squamous cell carcinomas of the lip involves three descriptors: T, N, and M. The T descriptor is based on the diameter or surface area of the tumor. The N descriptor describes nodal status. The M descriptor indicates distance of metastasis beyond the neck. This staging criteria allows physicians to predict patient outcomes and choose appropriate therapy based on comparisons with patients in large studies.

A TNM classification table is shown on page below

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A 62-year-old man is being evaluated for mandibular reconstruction after undergoing segmental mandibulectomy and resection of the anterior floor of the mouth for management of squamous cell carcinoma. On examination, the mandibular defect extends from the ipsilateral canine to the contralateral bicuspid; the tongue and remaining dentition have been preserved.

Which of the following is the most appropriate method for reconstruction of this patient's defect?

(A) Fibula osteocutaneous free flap
(B) Pectoralis major/rib osteomyocutaneous transposition flap
(C) Pectoralis major myocutaneous flap and reconstruction plate
(D) Radial forearm osteocutaneous free flap and iliac crest bone graft
(E) Radial forearm fasciocutaneous free flap and reconstruction plate

 

The correct response is Option A.

Reconstruction of the anterior mandible is best accomplished with the fibula osteocutaneous free flap. This flap provides excellent bone quality and a segmental blood supply, which allows for multiple osteotomies. This is crucial because successful reconstruction of the anterior mandible will require a minimum of two osteotomies in order to restore the contour of the mandibular arch.

Pectoralis major flaps with attached rib have been shown to be inadequate for mandibular reconstruction because of the poor quality of bone and difficulties with orientation. In addition, reconstruction plates are especially susceptible to fracture and exposure when used in the anterior mandible. Although the radial forearm flap provides excellent soft tissue for replacement of intraoral lining, only a limited amount of bone can be harvested, and osteotomies are poorly tolerated. Bone grafts are useful for reconstruction of defects less than 3 cm in patients who will not be undergoing radiation therapy.

 

43

Which of the following is the most common site of squamous cell carcinoma affecting the paranasal regions?

(A) Anterior ethmoidal sinus
(B) Frontal sinus
(C) Maxillary sinus
(D) Posterior ethmoidal sinus
(E) Sphenoid sinus

The correct response is Option C.

Although squamous cell carcinoma rarely affects the paranasal regions, 80% of tumors that do appear in this region arise within the maxillary sinus. The ethmoid, frontal, and sphenoid sinuses are affected less frequently.

Approximately 3% of malignancies involving the upper aerodigestive tract are found within the nasal and paranasal regions. Furthermore, approximately 70% of malignant tumors seen in this region are squamous cell carcinomas; this frequency is thought to be related to exposure to nickel and other chemicals.

The nasal floor is typically not associated with the development of malignancy but can be affected as a result of direct tumor extension, as many tumors are asymptomatic and thus remain undiagnosed while enlarging and advancing locally.

 

44

A 45-year-old man with a 50 pack/year history of smoking has a 4.5-cm lesion in the midline of the lower lip. Histologic examination of a biopsy specimen of the lesion shows findings consistent with squamous cell carcinoma. Intraoperative examination shows extension of the tumor to the mandible without erosion or invasion of the mandible. There are no palpable lymph nodes or evidence of sensory or motor nerve involvement.

Which of the following is the most appropriate management?

(A) Surgical excision alone
(B) Surgical excision with neck dissection
(C) Surgical excision with neck dissection and marginal mandibulectomy
(D) Surgical excision with neck dissection and segmental mandibulectomy
(E) Surgical excision with neck dissection and adjuvant chemotherapy and radiation therapy

 

The correct response is Option C.

This patient who has a squamous cell carcinoma of the lip should undergo surgical excision of the lesion with bilateral supraomohyoid neck dissection and marginal mandibulectomy. A 4.5-cm tumor of the lower lip with extension into the mandible but without palpable nodes in the neck is classified as T3 N0 M0. One study of patients with squamous cell carcinoma reported neck metastases in 63% of patients with T3 lesions; therefore, selective neck dissection is warranted. Marginal mandibulectomy is also appropriate in this patient who has tumor extension, but not invasion, into the mandible.

Segmental mandibulectomy is not required because the tumor has not invaded the mandible. Adjuvant chemotherapy is not recommended for patients with squamous cell carcinoma of the lip. Radiation therapy alone may be an option in patients with N0 tumors who are at increased risk for metastases or in patients who are poor surgical candidates, but radiation therapy is not used in combination with chemotherapy.

 

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A 70-year-old woman has a firm, pink 1.2-cm nodule located anterior to the tragus. Histologic examination of an incisional biopsy specimen of the lesion shows Merkel cell carcinoma. Which of the following is the most appropriate management?

(A) Excision with 1-cm margins and ipsilateral neck dissection
(B) Excision with 1-cm margins, superficial parotidectomy, and ipsilateral neck dissection
(C) Excision with 3-cm margins
(D) Excision with 3-cm margins and ipsilateral neck dissection
(E) Excision with 3-cm margins, superficial parotidectomy, and ipsilateral neck dissection

 

The correct response is Option E.

The most appropriate management of this patient's Merkel cell carcinoma is excision with 3-cm margins followed by superficial parotidectomy and ipsilateral neck dissection. Merkel cell carcinoma is a rare cutaneous malignancy believed to arise from neuroendocrine cells within the skin. It typically occurs on the head, neck, and other sun-exposed areas in patients 50 to 70 years of age. Lymphatic and distant metastasis are common, and prognosis is poor; mortality rates as high as 67% have been reported. Excision of the tumor with margins of 2 to 5 cm is generally recommended; prophylactic neck dissection is advocated because approximately 50% of affected patients have positive regional nodes at the time of initial diagnosis. Because the parotid gland is a primary drainage basin for preauricular lesions, superficial parotidectomy should also be performed. Although radiation therapy can be performed adjuvantly, it is inadequate when used with excision alone.

 

46

A 70-year-old man who has smoked cigarettes for the past 37 years has a 2.5-cm indurated mass of the lateral floor of the mouth that is adherent to the body of the mandible. A 2-cm lymph node can be palpated in the ipsilateral submandibular region; there are no distant metastases. Histologic examination of a biopsy specimen of the lesion shows squamous cell carcinoma. 

According to TNM classification, which of the following is the correct clinical classification of this tumor?

(A) T2 N1 M0
(B) T3 N1 M0
(C) T3 N2 M0
(D) T4 N1 M0
(E) T4 N2 M0

 

The correct response is Option D.

In this patient who has a 2.5-cm squamous cell carcinoma of the lateral floor of the mouth that is adherent to the adjacent mandible, as well as a 2-cm palpable lymph node but no evidence of distant metastases, the tumor is correctly classified as T4 N1 M0. The staging of squamous cell carcinomas of the oral cavity involves three descriptors: T, N, and M. The T descriptor is based on the diameter or surface area of the primary tumor. The N descriptor describes nodal status. The M descriptor indicates distance of metastasis beyond the neck. This staging criteria allows physicians to predict patient outcomes and choose appropriate therapy based on comparisons with patients in large studies.

A TNM classification table for squamous cell carcinoma of the oral cavity is shown below.

 

47

A 31-year-old man has pain and loosening of mandibular teeth associated with a rapidly expanding mass in that region. Histologic examination of a biopsy specimen shows osteogenic sarcoma. Which of the following is the most appropriate management?

(A) External beam radiation therapy
(B) Interstitial brachytherapy
(C) Chemotherapy
(D) Radical excision
(E) Radical excision followed by chemotherapy and radiation therapy

 

The correct response is Option E.

Radical excision remains the recommended primary treatment method for patients with osteogenic sarcoma, which is an aggressive, rapidly expanding mass often seen in the maxilla or mandible. However, adjuvant chemotherapy and radiation therapy have also been recommended as of late; clinical randomized trials of patients with osteogenic sarcoma have shown improved disease-free survival rates following chemotherapy and radiation therapy in patients with tumors affecting either the head and neck or the extremities. In addition, combination therapy is recommended because these tumors recur frequently.

The mean age of onset of osteogenic sarcoma is age 31 years; symptoms at initial presentation include jaw pain and loosening of teeth. Risk factors include fibrous dysplasia and retinoblastoma, as well as previous exposure to ionizing radiation or colloidal thorium dioxide (Thorotrast).

In patients who undergo surgical resection alone, five-year survival rates range from 23% to 35%.

 

48

Which of the following is the most common site of minor salivary gland malignancies?

(A) Buccal mucosa
(B) Floor of the mouth
(C) Lip
(D) Palate
(E) Tongue

 

The correct response is Option D.

Approximately 9% of all salivary gland tumors originate within the minor salivary glands; the palate is the most common site of origin, with 50% of all minor gland tumors occurring here. In contrast, only 15% of all minor salivary gland tumors originate in the lip, 12% in the buccal mucosa, and 5% in both the tongue and floor of the mouth.

Most minor salivary gland malignancies are classified histologically as adenoid cystic carcinomas, but other types can also be seen. The tumors affecting these glands are often smooth submucosal masses that are rarely associated with pain and numbness. Rapid tumor growth, pain, and ulceration are indicators of malignancy. Appropriate management of minor salivary gland tumors includes surgical resection with adequate margins, including any involved mucosa, muscle, or bone. Radiation therapy is recommended postoperatively for management of tumors with high-grade histologic features, positive surgical margins, perineural spread, deep invasion into muscle or bone, or lymph node metastasis.

 

49

A 64-year-old man develops a chylous fistula 10 days after undergoing left total parotidectomy and radical neck dissection for management of a parotid gland malignancy with metastasis to the ipsilateral neck. In addition to initiation of a medium-chain triglyceride diet, which of the following is the most appropriate management?

(A) Repair of the thoracic duct
(B) Closed suction drainage of the neck
(C) Radiation therapy of the neck and parotid bed
(D) Mediastinal exploration with ligation of the thoracic duct
(E) Surgical exploration of the neck with interposition of a pectoralis major myocutaneous flap

 

The correct response is Option B.

In this patient who has a chylous fistula, the most appropriate management is initiation of a medium-chain triglyceride diet and closed suction drainage of the neck. Chylous fistulas develop as a result of injury to the thoracic duct as it enters the jugular vein at the inferior region of the left neck; this finding is seen in as many as 4% of patients who have undergone radical neck dissection on the left. A medium-chain triglyceride diet will curb the flow of chyle into the region, while closed suction drainage will remove the existing chyle, allowing for closure of the fistula. Mediastinal exploration with ligation of the thoracic duct may be considered in patients who have refractory fistulas.

Repair of the thoracic duct is generally not performed initially. Radiation therapy should only be considered after closure of the fistula. Although interposition of a pectoralis major myocutaneous flap may help to seal the fistula, it should not be considered as a first-line treatment.

 

50

A 68-year-old woman has had a slowly enlarging nodule on the right upper eyelid for the past eight months. Physical examination shows a dark purple 8-mm nodule on the eyelid; ipsilateral parotid and cervical nodes can be palpated. Histologic examination of a biopsy specimen of the lesion shows uniform sheets of small oval cells within the deep epidermis and subcutaneous fat that have indistinct margins. 

These findings are most consistent with

(A) basal cell carcinoma
(B) malignant melanoma
(C) Merkel cell carcinoma
(D) microcystic adnexal carcinoma
(E) squamous cell carcinoma

The correct response is Option C.

This patient has findings consistent with Merkel cell carcinoma, an extremely aggressive tumor most commonly encountered in the head and neck region of elderly women. These nodules are pink to deep purple in color and rarely ulcerate. Light microscopy will show dense sheets of oval cells with indistinct borders that invade the deep dermis, subcutaneous fat, and muscle while sparing the papillary dermis and epidermis. Some surgeons advocate the use of electron microscopy and immunohistochemistry because these lesions can be mistaken for metastatic oat cell carcinoma or poorly differentiated lymphoma. A biopsy specimen of the lesion will most likely stain positive for neuron-specific enolase.

Because 33% of affected patients will experience a local recurrence within one year of initial treatment and approximately 50% will ultimately develop nodal metastases, wide local excision with a margin of 2.5 cm to 3 cm is indicated. En bloc resection of involved nodes and postoperative radiation therapy are also recommended; chemotherapy and prophylactic nodal dissection are controversial treatment options. Long-term survival rates are poor; only 55% of patients diagnosed with Merkel cell carcinoma will survive for three years. Factors that are associated with a poor prognosis include male gender, early age at initial onset, and location of the tumor on the head, neck, or trunk.

Basal cell carcinomas are common slow growing tumors of the head and neck that can be pigmented or ulcerated. Because these tumors rarely metastasize, local excision with 5 mm margins is recommended. 

Malignant melanoma is a highly aggressive tumor of brown pigmentation that often develops within an existing nevus. Exposure to ultraviolet radiation has been associated. Melanomas of the hands and feet are associated with a significantly worse prognosis than those of the arm and leg. Excision with wide margins is advocated for treatment of malignant melanoma.

Microcystic adnexal carcinomas are rare, flesh colored nodules involving the upper lip, nose, and periorbital regions in middle aged patients. Perineural invasion is almost always seen with this locally aggressive and often recurrent tumor. Ulceration and nodal metastases are rare. Appropriate management of microcystic adnexal carcinoma is Mohs' micrographic resection, including complete histologic examination of the tumor margins. Radiation therapy is ineffective.

Squamous cell carcinomas arise from the malpighian layer and have a strong association with actinic radiation. Cutaneous squamous cell carcinomas have a rough, ulcerated appearance and most frequently affect the head and neck region. The overall rate of metastasis is extremely low. Direct excision or radiation therapy are equally advocated as initial treatment. Recurrent lesions are treated with Mohs' micrographic resection.

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