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Flashcards in Head and Neck Tumors Deck (35):
1

An otherwise healthy 59-year-old woman is scheduled to undergo resection of recurrent squamous cell cancer of the right temporal area 5 years after initial resection, superficial parotidectomy, limited upper cervical lymphadenectomy, skin grafting, and adjuvant radiation therapy. The anticipated defect will be 6 × 8 cm, involving the skin and subcutaneous tissues. The superficial temporal vessels cannot be identified. Which of the following is the most appropriate method of wound closure?
A) Lateral arm flap
B) Parascapular flap
C) Radial forearm free flap
D) Scalp rotation flap
E) Split-thickness skin grafting

C) Radial forearm free flap

The most appropriate method for wound closure is a radial forearm free flap, as it matches the thin skin and subcutaneous tissue of the temporal area and has a long pedicle that can reach recipient vessels in the neck. With a patient history of radiation therapy and superficial parotidectomy, the superficial temporal vessels are unlikely to be suitable recipient vessels. With a patient history of upper neck dissection, it is possible that suitable recipient vessels will only be found inferiorly, and thus, it is best to use a flap with a long, reliable pedicle. A split-thickness skin graft will likely fail in a radiated wound bed. A scalp rotation flap will likely include tissue in the radiation field, bring hair-bearing tissue into a non–hair-bearing area, and require a split-thickness skin graft for closure of the donor site. It could be considered in a patient who is not a candidate for free tissue transfer. The lateral arm flap and parascapular flap are slightly thicker than the radial forearm flap, but the principal reason to avoid these flaps in this patient is that their pedicle lengths are relatively short and may not reach the recipient vessels in the neck.

2

A 45-year-old woman is evaluated for a 2.5-cm, biopsy-proven squamous cell carcinoma of the left floor of the mouth. Imaging studies show cortical mandibular invasion, but no enlarged cervical lymph nodes or distant metastatic disease. A tracheostomy is performed. Immediate reconstruction is planned. Which of the following is the most appropriate surgical treatment for this cancer?
A) Wide local excision alone
B) Wide local excision and marginal mandibulectomy
C) Wide local excision and neck dissection
D) Wide local excision, marginal mandibulectomy, and neck dissection
E) Wide local excision, segmental mandibulectomy, and neck dissection

E) Wide local excision, segmental mandibulectomy, and neck dissection

Oral cavity cancers are staged based on the following criteria set forth by the American Joint Committee on Cancer:

Primary tumor staging for oral cavity cancers (T)
TX Primary tumor cannot be assessed
T0 No evidence of primary tumor
Tis Carcinoma in situ
T1 Tumor = 2 cm in greatest dimension
T2 Tumor >2 cm but not more than 4 cm in greatest dimension
T3 Tumor >4 cm in greatest dimension
T4a Moderately advanced, local disease
Lip – Tumor invades through cortical bone, inferior alveolar nerve, floor of mouth, or skin of face
Oral cavity – Tumor invades adjacent structures (e.g., through cortical bone, into deep extrinsic muscle of the tongue, maxillary sinus, or skin of face)
T4b Very advanced, local disease
Tumor invades masticator space, pterygoid plates, or skull base and/or encases internal carotid artery
The cancer described is a stage T4aN0M0 cancer of the floor of mouth. The T-stage is 4a based on cortical mandibular invasion demonstrated by radiographic imaging. Concern for mandibular invasion should be raised whenever a tumor abuts or is fixed to the mandible.

Mandibulectomy is indicated. Cortical invasion of the mandible is an indication for segmental mandibulectomy, in which the full thickness of the involved mandible and grossly disease-free margin are removed by osteotomies. Marginal mandibulectomy involves removal of the alveolar ridge and varying amounts of the inner or lingual table of the mandible depending on the location of the tumor. Marginal mandibulectomy is performed when cancers abut the mandible or invade the periosteum, but do not grossly invade the cortex of the bone.

Although clinically and radiographically the neck does not have nodal metastases (stage N0), surgical treatment is usually performed due to the risk for occult nodal metastases (20% or more in some studies). Such dissection also facilitates reconstruction by exposing potential recipient blood vessels for microvascular free tissue transfer.

3

In patients with ameloblastoma, which of the following cell populations gives rise to this tumor?
A) Cementoblast tissue
B) Enamel
C) Gingiva
D) Nerve root
E) Odontogenic epithelium

E) Odontogenic epithelium

Ameloblastomas are benign odontogenic tumors derived from odontogenic epithelium. They are typically slow growing, and present in the fourth or fifth decade of life as a mandibular mass in most individuals (80%).

Odontogenic cementoblast tissue is not appropriate because this tissue gives rise to an extremely rare benign odontogenic tumor, the cementoma.

Gingiva is the mucosal covering of the alveolar bone.

Enamel is the dense compound of teeth.

4

Which of the following factors is most likely to increase the risk for osteoradionecrosis secondary to radiation therapy?
A) Dental caries
B) Edentulous mandible
C) Oral thrush
D) Osseointegrated implants
E) Radiation dose of 3500 cGy

A) Dental caries

Osteoradionecrosis (ORN) of the mandible is uncommon but can occur in up to 10% of patients after undergoing radiation therapy for oral cancers. The risk increases once radiation doses exceed 6500 cGy. Most reports of ORN have dental caries and extraction sites as precipitating factors. Periodontal disease can also lead to ORN. After undergoing radiation therapy, patients can develop oral candidiasis and xerostomia, and they may also have edentulous mandibles with dental implants after reconstruction. However, these do not increase the risk for ORN. Surgical resection and hyperbaric oxygen therapy are the mainstays of treatment.

5

A 68-year-old man with a history of laryngeal cancer treated with chemoradiation 2 years ago has a recurrence. He is scheduled for total laryngopharyngectomy with circumferential resection of the pharynx extending from the floor of the mouth to 2 cm above the manubrium. Which of the following is the most appropriate single-stage reconstruction?
A) Construction of a spit fistula
B) Coverage with an anterolateral thigh flap
C) Coverage with a deltopectoral flap
D) Coverage with a pectoralis flap
E) Use of gastric pull-up

B) Coverage with an anterolateral thigh flap

The circumferential defect described in this patient requires coverage with a tubularized flap that can span the length of the defect and reestablish continuity of the alimentary track. Gastric pull-up is not a good option in this case because of its high morbidity and poor perfusion in the most proximal region of the gastric flap. Coverage with the pectoralis flap or deltopectoral flap is not an appropriate option because these flaps cannot be tubularized in a single-stage reconstruction. The spit fistula would not restore alimentary tract continuity, and it should only be used if no other reconstructive options are available or if the patient is medically unstable. The anterolateral thigh flap is the best option in this case because it can be tubularized to span the defect. In most cases, the resulting reconstruction is highly effective with restoration of swallowing function in the majority of patients.

6

An otherwise healthy 35-year-old woman is evaluated for a 3-cm left parotid mass. Physical examination shows weakness of facial muscles on the side of the tumor. CT scan shows several enlarged cervical lymph nodes. Parotidectomy is performed, and pathologic examination shows a mixed population of poorly differentiated epithelial cells and intermediate cells with occasional secretory cells and neural invasion. Which of the following is the most likely diagnosis?
A) Hemangioma
B) Mucoepidermoid carcinoma
C) Pleomorphic adenoma
D) Squamous cell carcinoma
E) Warthin tumor

B) Mucoepidermoid carcinoma

Salivary gland tumors are relatively rare and make up about 3 to 4% of all head and neck neoplasms. Approximately 80% of salivary gland tumors originate in the parotid gland. Approximately 80% of parotid gland tumors are benign. Facial paralysis may be associated with malignant tumors and is a sign of neural invasion. Malignant tumors may also metastasize to the regional lymph nodes and to distant sites.

Mucoepidermoid carcinoma is the most common malignancy of the parotid gland and the second most common malignancy of the submandibular and minor salivary glands. Mucoepidermoid carcinomas contain two major elements: mucus-secreting cells, and epithelial cells of the epidermoid variety. Low-grade tumors are associated with a predominance of mucus-secreting cells lining cysts and intervening nests of well-differentiated epidermoid cells. High-grade tumors show few or no mucus-secreting cells and the epidermoid cells are poorly differentiated. Intermediate-grade tumors are defined by less cyst formation than low-grade tumors with nests of epidermoid and less differentiated intermediate cells. The biologic behavior of mucoepidermoid carcinomas correlates with their histologic grade. On the basis of the nerve invasion, the appropriate treatment for this patient includes radical parotidectomy with facial nerve sacrifice. A neck dissection should also be performed for high-grade lesions or those with suspicious adenopathy. Postoperative radiation therapy is usually recommended for higher-grade mucoepidermoid cancers.

Pleomorphic adenoma, also known as benign mixed tumor, is the most common benign tumor of the parotid gland. This tumor is histologically characterized by epithelial and connective tissue elements, with stellate and spindle cells interspersed with a myxoid background. Warthin tumor (papillary cystadenoma lymphomatosum) is the next most common tumor of the parotid gland and is also benign. Warthin tumors predominantly occur in males and are bilateral in 10% of patients. Histologically, they are characterized by papillary cysts and mucoid fluid as well as nodules of lymphoid tissue. Hemangiomas are the most common salivary gland tumors found in children, and usually involve the parotid gland. Like other hemangiomas, they are benign and characterized by a rapid growth phase around the age of 1 to 6 months, followed by gradual involution over 1 to 12 years. Histologically, the tumors are composed of capillaries lined by proliferative endothelial cells. Squamous cell carcinoma is a malignant tumor that rarely involves the parotid gland, in comparison with the skin and aerodigestive tract. When squamous cell cancers occur in the parotid gland, they are usually of metastatic origin, although primary squamous cancers of the salivary glands do occur. They are histologically identical to squamous cell cancers arising from other sites with epithelial cells that form sheets or compact masses that invade adjacent connective tissue. Round nodules of keratinized squamous cells, known as “keratinous pearls,” are the hallmark of well-differentiated squamous cell carcinoma.

7

A 47-year-old man is referred for examination of a composite defect of the mandible that extends from the right mandibular angle to the left mandibular angle. Which of the following flaps is most appropriate for reconstruction in this patient?
A) Fibula
B) Pectoralis
C) Radial forearm
D) Rectus
E) Scapula

A) Fibula

The fibula flap is the most appropriate option in this case because a long section of bone requiring multiple osteotomies is needed. The fibula flap can provide 18 to 20 cm of bone and has both an endosteal and periosteal blood supply enabling shaping of the bone with multiple osteotomies. In addition, a skin paddle can be harvested with the flap to reconstruct the floor of mouth defect. The scapula and radial forearm flaps also provide bone and soft tissues; however, these flaps will not provide a long enough bone segment and cannot be reliably osteotomized in multiple locations. The rectus and pectoralis flaps are soft-tissue flaps, and their use in this case would result in marked deformity because the anterior arch has been resected.

8

A 55-year-old man is referred because of a 1-year history of ear and throat pain. Physical examination shows a 1-cm exophytic tumor of the anterior tonsillar pillar within the oropharynx. Biopsy of the tumor shows squamous cell carcinoma. Which of the following cervical lymphatic levels is most likely to be first involved in this patient?
A) I
B) II
C) III
D) IV
E) V

B) II

The anterior tonsillar pillar (palatoglossal arch) and tonsil are the most common site for primary neoplasms of the oropharynx. A 1-cm tumor (T1) at this location has a 71% incidence of cervical lymph node metastases. Oropharyngeal tumors arising at the base of the tongue have a similar incidence of lymphatic metastases, whereas oropharyngeal wall and soft palate T1 tumors only metastasize in 8 to 25% of cases. The most direct path of lymphatic drainage from the oropharynx is to level II (jugulodigastric) lymph nodes, which can be examined clinically. From level II the progression is sequential to levels III, IV, and V. It is rare to encounter a “skipped” level. The other less frequent lymphatic drainage pathways detectable only on imaging studies are to retropharyngeal and parapharyngeal nodes. Midline tumors can drain to bilateral lymphatic systems.

9

A 70-year-old man is evaluated following tumor resection. Physical examination shows a 4 × 4-cm defect of the right maxilla that includes all of the teeth posterior to the right canine (two premolars and three molars) but spares the right orbital floor. He did not undergo radiation therapy. He wishes to restore mastication, speech, and swallowing by the simplest means that will still be efficacious. Which of the following is the most appropriate method of reconstruction?
A) Fibula osteocutaneous free flap with osseointegrated implants
B) Osseointegrated implant–retained prosthesis
C) Prosthetic obturator
D) Rectus abdominis musculocutaneous free flap with a conventionally retained dental prosthesis
E) Temporalis muscle pedicled flap

C) Prosthetic obturator

Palatal obturators can adequately restore missing maxillary dentition as well as prevent oronasal leakage of air, liquids, and foods. They have the advantage of being removable, which permits visualization of the maxillary cavity for tumor surveillance. Prosthetic retention can be difficult or impossible in sizable defects, particularly when there are few teeth to stabilize the prosthesis. In this patient who has sufficient remaining maxillary teeth and the majority of the alveolar arch, the prosthesis is expected to have good stability, and would be the appropriate choice in a patient who wishes to avoid further invasive procedures.

The temporalis muscle flap can be transposed into the oral cavity and can be used for closing defects of the palate. However, this flap alone would not provide replacement of the missing dentition and is still more invasive than a palatal obturator. Additionally, the temporalis muscle flap results in marked temporal hollowing at the donor site. The rectus abdominis musculocutaneous free flap can close the palatal defect and restore shape to the cheek in patients with a unilateral maxillectomy. In combination with a dental prosthesis, the rectus abdominis musculocutaneous free flap can restore the patient’s appearance and function. However, the rectus abdominis musculocutaneous free flap is also an invasive procedure, and it can sometimes be challenging to inset the flap such that there is enough room in the mouth for a prosthesis. In a patient who has had a maxillectomy, there is generally inadequate remaining bone stock to place osseointegrated implants for prosthetic retention. The patient’s existing dentition should be adequate to support a prosthesis. The fibula osteocutaneous free flap and other osteocutaneous flaps can be used to close the palatal defect to prevent nasal regurgitation. The fibula osteocutaneous free flap can also accept osseointegrated implants for dental restoration due to the good quality of bone stock associated with this flap. However, fibula free flap and osseointegrated implant reconstruction is a very long and extensive procedure and can require more than one surgery to fully restore this patient, particularly if osseointegrated implants are not placed during the same procedure as the free flap reconstruction.

10

A 60-year-old man is evaluated for a 6-cm ameloblastoma of the right maxilla. Reconstruction using an osteocutaneous iliac crest free flap is planned. Which of the following arteries supplies arterial blood to this flap?
A) Deep circumflex iliac
B) Deep inferior epigastric
C) Descending genicular
D) Lateral circumflex femoral
E) Peroneal

A) Deep circumflex iliac

The deep circumflex iliac artery is the major blood supply to the iliac crest free flap. It gives rise to periosteal branches and nutrient endosteal branches that supply the iliac crest bone posterior to the anterior superior iliac spine. It also gives rise to an ascending branch that supplies the internal oblique muscle and several musculocutaneous perforators that supply the overlying skin, allowing a myo-osseous or osteocutaneous free flap to be harvested, respectively. Use of the iliac crest osteocutaneous free flap has been described by several authors for maxillary as well as mandibular reconstruction, and the bone itself provides ample stock for accommodating osseointegrated implants for dental restoration.

The peroneal artery is the blood supply to the fibula free flap. Use of this flap is contraindicated when the peroneal artery contributes markedly to the blood supply of the distal lower extremity. The descending genicular artery is a branch of the superficial femoral artery and is the blood supply to the medial femoral condyle osseous free flap. Alternately, the medial superior genicular artery, another branch of the superficial femoral artery, can be used to supply this flap, but the pedicle is shorter. The descending branch of the lateral circumflex femoral artery is the blood supply to the anterolateral thigh free flap, which is a cutaneous perforator flap. The deep inferior epigastric artery is the blood supply to the rectus abdominis musculocutaneous free flap or the deep inferior epigastric perforator flap.

11

Which of the following types of head and neck tumors are most often associated with Epstein-Barr virus infection?
A) Larynx
B) Maxillary sinus
C) Nasopharynx
D) Tongue
E) Tonsil

C) Nasopharynx

Nasopharyngeal cancers are most often associated with Epstein-Barr virus (EBV) infections and arise from the mucous epithelium of the nasopharynx and are relatively rare in the United States. However, these tumors are endemic in Africa and East Asia, accounting for as many as 18% of head and neck cancers in China. Nasopharyngeal tumors are classified as either squamous cell cancers, keratinizing undifferentiated carcinoma, or non-keratinizing undifferentiated carcinoma. EBV infection is most strongly associated with the non-keratinizing undifferentiated subtype and is thought to increase malignant transformation. Nasopharyngeal cancers are most commonly treated with chemotherapy and radiation, with surgery reserved for recurrent or unusual cancers. Reconstruction of skull base defects is most commonly performed using microsurgical transfer of soft-tissue flaps. Alcohol and tobacco are the most common risk factors for head and neck cancers in general, and laryngeal cancers in particular, with cigarette smoking increasing the lifetime risk 5- to 25-fold. Other risk factors for head and neck cancers in general include cigar smoking, environmental exposures, dietary factors (red meat, betel nuts), and human papillomavirus (HPV) infection. HPV infections are most commonly associated with oropharyngeal cancers (tongue, tonsil). Significant risk factors for maxillary sinus cancers include cigarette smoking and environmental factors such as exposure to wood dust.

12

A 16-year-old boy comes to the office because of a progressive 6-month history of unilateral nasal obstruction and frequent epistaxis. Anterior rhinoscopy shows a soft, smooth, purplish lobulated mass filling the left nasal cavity. An attempted office biopsy results in profuse bleeding. Which of the following is the most likely diagnosis?
A) Dermoid cyst
B) Encephalocele
C) Hemangioma
D) Inverted papilloma
E) Nasopharyngeal angiofibroma

E) Nasopharyngeal angiofibroma

Nasopharyngeal angiofibromas, also known as juvenile nasopharyngeal angiofibromas, are benign but locally invasive vascular tumors that occur almost exclusively in adolescent males. Onset is most common in the second decade of life, and rarely occurs after age 25 years. Symptoms include unilateral or bilateral nasal obstruction, frequent epistaxis or blood-tinged nasal discharge, and conductive hearing loss from Eustachian-tube obstruction. In advanced stages, the angiofibroma can deform the nose, face, and orbits, as well as erode into the cranial cavity and put pressure on the optic chiasm, resulting in diplopia. Treatment is usually surgical with radiation and reserved for extensive cases such as those with intracranial extension. Preoperative embolization as well as hormone therapy with estrogens, may limit blood loss. Nasopharyngeal angiofibromas are highly vascular, and office biopsies should be avoided.

Inverted papilloma is a benign, locally aggressive neoplasm that arises in the nasal cavity and is associated with squamous cell carcinoma in approximately 5% of patients. The age of onset is usually between 40 and 60 years. Surgery is the primary treatment of inverted papilloma. Encephaloceles are neural tube defects that result in sac-like protrusions of the meninges (meningocele) or brain and meninges (meningoencephalocele) in various locations along the cranium, including intranasally. They tend to be bluish, soft, compressible masses that transilluminate. Biopsy may result in a cerebrospinal fluid leak. Hemangiomas are benign vascular lesions that are present at birth and characterized by a rapid growth phase around the age of 1 to 6 months followed by gradual involution over 1 to 12 years. A hemangioma would not be expected to first occur in adolescence. Dermoid cysts are derived from ectodermal and mesodermal tissue and may contain skin, hair follicles, sebaceous glands, and sweat glands. Dermoids are usually firm and noncompressible and most frequently occur as a slow-growing cystic mass over the dorsum of the nose, but may also be entirely intranasal. Dermoid cysts may also have a dural component and should not be biopsied until intracranial communication can be ruled out by x-ray studies. Encephaloceles, hemangiomas, and dermoid cysts are congenital nasal masses that occur in infancy rather than adolescence.

13

A 58-year-old man undergoes total laryngopharyngectomy for recurrent squamous cell carcinoma. The pedicle to the most appropriate flap for reconstruction of the resulting total circumferential pharyngectomy defect extending from the base of the tongue to the cervical esophagus is located between which of the following muscles?
A) Flexor carpi radialis and palmaris longus
B) Teres minor, teres major, and long head of the triceps
C) Teres minor, teres major, long head of the triceps, and humerus
D) Vastus lateralis and rectus femoris
E) Vastus medialis and rectus femoris

D) Vastus lateralis and rectus femoris

The best option for reconstruction in this patient requiring circumferential pharyngeal reconstruction is the anterolateral thigh flap. This fasciocutaneous flap is supplied by perforators from the descending branch of the lateral femoral circumflex vessels, which are a branch of the profunda femoris vessels. The descending branch runs between the vastus lateralis and rectus femoris muscles, not the vastus medialis and rectus femoris.

The radial forearm flap is based on the septum between the flexor carpi radialis and brachioradialis muscles in the arm. Although it can be used to reconstruct partial, noncircumferential pharyngectomy defects, it is not ideal for a long, circumferential defect in a previously radiated neck.

The pedicle runs between the flexor carpi radialis and brachioradialis, not the palmaris longus.

The circumflex scapular artery emerges from the triangular space in the back, which is defined by the teres minor, teres major, and the long head of the triceps. It is the pedicle to the parascapular and scapular flaps.

Option C defines the quadrangular space that transmits the axillary nerve and posterior humeral circumflex artery.

14

A 39-year-old woman undergoes a total parotidectomy with facial nerve preservation for mucoepidermoid carcinoma of the parotid gland. The final pathology report indicates microscopic disease at the deep margin, and follow-up imaging shows no gross residual disease. No detectable nodal or other metastases are noted. Which of the following is the most appropriate next step in management?
A) Chemotherapy
B) Immunotherapy
C) Neck dissection
D) Radiation therapy
E) Reexcision of the deep margin

D) Radiation therapy

The patient described likely has a stage III tumor (T3 N0 M0). Standard management algorithms developed by the National Comprehensive Cancer Network recommend adjuvant radiation treatment when the persistence of positive margins relates to microscopic disease and not gross disease. If there is gross disease, either by physical examination or follow-up imaging, and it is resectable, then surgical resection of the residual disease should be done initially, followed by adjuvant radiation.

Chemotherapy for major salivary gland tumors is appropriate as a first-line therapy concomitant with radiation only in cases of squamous cell carcinoma. In patients with mucoepidermoid, adenoid cystic, and adenocarcinomas, the role of chemotherapy is mainly palliative and reserved for advanced situations of recurrent or distant systemic disease. The absence of standard chemotherapy protocols for these situations attests to the degree of response that can be expected.

Immunotherapy has no significant role in the treatment of major salivary gland malignancies.

Neck dissection is indicated for malignant salivary gland tumors with clinically positive nodes detected either on physical examination or with preoperative imaging workup. This applies to parotid tumors of either the superficial or the deep lobe. Typical imaging to identify nodal disease would include CT scan or MRI or both.

Neck dissections performed electively are rarely indicated, and only in very high-risk situations that are based on factors other than clinical and histologic features of the primary tumor. Radiation treatment is an effective treatment for negative necks with high risk of nodal disease, and is preferred over elective neck dissections.

Surgical resection of persistent disease is indicated when a previously treated parotid mass was incompletely resected, and the remaining tumor is gross and resectable, rather than just microscopic. If not resectable, then the patient should have definitive radiation treatment.

15

A 45-year-old woman comes to the office because of a painful 4-cm left parotid mass. Physical examination shows weakness of the left facial muscles. CT scan of the chest shows multiple lung nodules consistent with metastases. Parotidectomy is performed, and pathologic examination of the gland shows a cribriform (“Swiss cheese”) pattern of cells with perineural invasion. Which of the following is the most likely diagnosis?
A) Adenoid cystic carcinoma
B) Lymphangiosarcoma
C) Mucoepidermoid carcinoma
D) Pleomorphic adenoma
E) Warthin tumor

A) Adenoid cystic carcinoma

Salivary gland tumors are relatively rare and make up about 3 to 4% of all head and neck neoplasms. The majority of salivary gland tumors (approximately 80%) originate in the parotid gland. Approximately 80% of parotid gland tumors are benign. Malignant tumors are associated with facial paralysis and pain, although they may also be asymptomatic. Malignant tumors may also metastasize to the regional lymph nodes and to distant sites.

Pleomorphic adenoma, also known as benign mixed tumor, is the most common benign tumor of the parotid gland. This tumor is histologically characterized by epithelial and connective tissue elements, with stellate and spindle cells interspersed with a mixoid background.

Warthin tumor (papillary cystadenoma lymphomatosum) is the next most common tumor of the parotid gland and is also benign. Warthin tumors predominantly occur in males and are bilateral in 10% of patients. Histologically, they are characterized by papillary cysts and mucoid fluid as well as nodules of lymphoid tissue.

Mucoepidermoid carcinoma is the most common malignancy of the parotid gland and the second most common malignancy of the submandibular and minor salivary glands. Mucoepidermoid carcinomas contain two major elements: mucus-producing cells, and epithelial cells of the epidermoid variety. Low-grade tumors are associated with a predominance of mucus-secreting cells lining cysts and intervening nests of well-differentiated epidermoid cells. High-grade tumors show few or no mucus-producing cells and the epidermoid cells are poorly differentiated. Intermediate-grade tumors are defined by less cyst formation than low-grade tumors with nests of epidermoid and less differentiated intermediate cells. The biologic behavior of mucoepidermoid carcinomas correlates with their histologic grade.
Adenoid cystic carcinoma is the second most common tumor of the salivary glands and the most common malignant tumor of the submandibular, sublingual, and minor salivary glands. It is slightly more common in female patients and typically affects patients between the ages of 30 and 70 years with a peak incidence of 40 to 59 years. There are three histologic subtypes: cribriform, tubular, and solid. The cribriform pattern has a classic “Swiss cheese” appearance with cells arranged in nests separated by round or oval spaces. The tubular pattern has a glandular architecture, while the solid (or basaloid) pattern has sheets of cells with little or no luminal spaces. Adenoid cystic carcinoma usually exhibits a protracted course characterized by indolent growth and a propensity for perineural invasion, reported to occur in 20 to 80% of patients. Distant metastases, most frequently to the lung, are not uncommon.

Lymphangiosarcoma is a rare vascular tumor, which may be associated with prolonged lymphedema. These tumors are more commonly found in the extremities and under light microscopy appear as vascular channels with anaplastic endothelial cells.

16

A 40-year-old woman comes to the office because of a 5-year history of firm, painless swelling of the upper jaw that has increased progressively in size. CT scan is performed (soap bubble/honeycomb appearance odontogenic tumor) and the lesion is shown. Resection is performed. Pathologic examination shows odontogenic epithelial islands bordered by palisading columnar cells. No invasion into the surrounding tissues is noted. Which of the following is the most likely diagnosis?
A) Ameloblastoma
B) Fibrous dysplasia
C) Nasopharyngeal angiofibroma
D) Osteosarcoma
E) Squamous cell carcinoma

A) Ameloblastoma

Ameloblastomas are benign, locally invasive, odontogenic tumors accounting for 1% of tumors of the jaw and 10% of odontogenic tumors. Approximately 80% occur in the mandible and 20% occur in the maxilla. The peak incidence is in the third and fourth decades but may also arise in children and adolescents. Ameloblastomas may be radiographically found to be unilocular or, more commonly, multilocular with a “soap bubble” or “honeycomb” appearance. Treatment may be with enucleation and curettage or more radical resection. In rare cases, metastatic ameloblastoma and ameloblastic carcinomas have been reported.

Fibrous dysplasia is a benign hamartomatous lesion that has a diffuse, “ground-glass” appearance on x-ray studies. It is usually treated conservatively with shaving and re-contouring of the bone. Squamous cell carcinoma is usually associated with a painful mucosal lesion. Radiographically, bony invasion may be noted in locally advanced cases. Osteosarcomas are aggressive malignancies of mesenchymal origin that exhibit osteoblastic differentiation. They are the most common primary bony cancer. Their radiographic appearance is variable and may include nonspecific destruction of the bone similar to a carcinoma, mottled ossification, similar to fibrous dysplasia, but without well-defined borders, or lamellar ossification (sheets of neo-osteogenesis). Nasopharyngeal angiofibromas are benign but locally invasive vascular tumors that occur almost exclusively in male adolescents. Their symptoms include nasal obstruction but can eventually cause facial asymmetry and eye displacement, as they grow from the region of the sphenopalatine foramen first into the nasopharynx and choanae then into the paranasal sinuses, pterygopalatine and infratemporal fossae, orbit, and even the intracranial cavity. Radiographically, they are nonencapsulated, lobular soft-tissue masses that demonstrate intense uptake of intravenous contrast due to their highly vascular nature. Extensive bony destruction is usually not a feature, but bone may be remodeled or resorbed.

17

A 23-year-old man comes to the office because of a 1-year history of painless swelling, asymmetry, and loss of interdental relationships on the right side of the jaw. Physical examination shows crowding of the right-sided first and second molars and premolar dentition. The third molar has not erupted; in its place there is a palpable firm enlargement of the mandible. Panoramic x-ray study (Panorex) shows a 3-cm radiolucent unilocular cyst. Percutaneous biopsy of the cyst shows nonkeratinizing stratified squamous epithelium. Which of the following is the most likely diagnosis in this patient?
A) Dentigerous cyst
B) Gingival cyst
C) Gorlin cyst
D) Primordial cyst
E) Radicular cyst

A) Dentigerous cyst

The most appropriate answer is dentigerous cyst. This type of cyst develops in the context of an unerupted tooth, which can be seen below the cyst. The cyst is lined with benign nonkeratinizing epithelium and is caused by degeneration of the enamel reticulum of the unerupted tooth. It is the second most common type of jaw cyst. Two thirds occur in the mandible.

Gingival cysts appear most commonly on alveolar ridges of infants but can also rarely appear in adults. Their origin relates to rests of dental lamina, and, unlike dentigerous cysts, these contain keratin. Clinically, they are soft and fluctuant, and range in size between 1 and 15 mm.

Primordial cysts and odontogenic keratocysts are equivalent. They develop from rests of dental lamina and basal cell hamartomas. Therefore, unlike dentigerous cysts, these are lined with a keratinizing stratified squamous epithelium that is sometimes dysplastic. Their size range is 1 to 9 cm, and pain is a common symptom. Gorlin syndrome includes the association of multiple odontogenic keratocysts with multiple basal cell carcinomas, nasal deformity, skeletal abnormalities, calcification of the falx cerebri, and palmar or plantar pits.

Calcifying odontogenic (Gorlin) cysts are distinct from those above because they may be part cystic and part neoplastic. The histology shows features similar to the calcifying epithelioma of Malherbe (epithelium undergoing keratinization and calcification), and ameloblastic proliferations. Radiographically, they contain various amounts of radiopaque (calcified) material and are usually located anterior to the first molars ranging in size from 1 to 8 cm.
Radicular cysts are the most common type of jaw cysts and develop at the apex of a nonviable erupted tooth, from epithelial rests of Malassez in the periodontal ligament. As these cysts are inflammatory in nature rather than developmental, they are usually preceded by a periapical granuloma. Histology shows a fibrous shell lined with nonkeratinizing stratified squamous epithelium infiltrated with chronic inflammatory cells. Due to their painless quality, they most commonly occur as an incidental finding of routine x-ray studies of the maxilla. These cysts are radiolucent, and differ from dentigerous cysts because they are located at the apex of an erupted tooth rather than at the crown of an unerupted tooth.

18

A 37-year-old man is waiting for a facial deceased-donor vascularized composite allotransplant. Which of the following components of a total face transplant is most antigenic?
A) Bone marrow
B) Muscle
C) Nerve
D) Skin
E) Tendon

D) Skin

Vascularized composite allotransplantation refers to the transplantation of an allograft consisting of heterogeneous cadaveric tissues. It provides a means of restoring structural, functional, and aesthetic form in severely injured patients. The potential for improvements in quality of life must be offset by the need for lifelong immunosuppression in adults with non-life-threatening injuries. The benefits and difficulties of immunosuppressive drugs have been established in solid organ transplantation. Regimens derived from renal transplantation have been successfully applied to composite tissue allografts.

Overall, more than 60 hand/forearm/arm transplantations and 16 face transplantations have been performed in the past 12 years. The overall functional and aesthetic outcome is satisfactory, but side effects and complications related to immunosuppression are challenges hindering progress in this field. The high levels of immunosuppression, skin rejection, nerve regeneration, donor legislation, and the acceptance level need to be addressed to promote growth of this promising new field in transplantation and reconstructive surgery.

Because composite tissue allograft transplantations are not life-saving procedures, much consideration is devoted to the issue of minimizing or withdrawing immunosuppression. When compared with solid organ transplants, composite tissue allografts are histologically heterogeneous, composed of different tissue types (e.g., skin, muscle, bone, bone marrow, lymph nodes, nerve, and tendon) and express different immunogenicity of transplanted elements. The hierarchy of antigenicity of composite tissue allografts was introduced in an experimental model of limb transplantation and showed that skin is the most antigenic tissue, and together with muscle, subcutaneous tissue, and bone (including bone marrow), may generate high immunologic response. The vascularized muscle component of limb allografts may induce a cell-mediated response greater than the skin; however, muscle as a single component is less antigenic than skin. Bone represents lower immunogenicity, and cartilage, tendon, and vessels are the least antigenic.

19

A 32-year-old man comes to the office because of a pleomorphic adenoma in the right parotid. A mass is palpated over the angle of the mandible. Examination of the oral cavity and neck shows no abnormalities. Which of the following is the most appropriate surgical treatment?
A) Enucleation
B) Radical parotidectomy
C) Superficial parotidectomy
D) Total parotidectomy
E) Total parotidectomy and neck dissection

C) Superficial parotidectomy

The salivary gland neoplasms are uncommon and generally benign. Most benign tumors can be easily cured by wide local excision. Pleomorphic adenoma is the most common salivary gland tumor, with a propensity for local recurrence. Simple enucleation is discouraged. Removal is usually done by a superficial parotidectomy. The superficial lobe is anatomically defined by the traversing facial nerve. The nerve is preserved, as pleomorphic adenoma is a benign tumor that does not infiltrate the nerve. The parotid gland is also the most frequently affected major salivary gland, and the palatal salivary tissue is the most commonly affected minor salivary gland.

Pleomorphic adenomas are the most common neoplasm of salivary glands, comprising 45 to 75% of all tumors in most series. These tumors typically affect patients in their 20s to 50s and there is a female predilection. Warthin’s tumor is the second most common tumor of the salivary glands and constitutes approximately 14 to 21% of salivary gland neoplasms. The tumor is almost exclusively found in the parotid gland, typically affects males in their 50s to 60s, and often may be bilateral.

20

An obese 65-year-old man who undergoes resection of an oral tongue nodule has a 5 × 9-cm defect of the hemitongue and floor of the mouth. Which of the following is the most appropriate method of reconstruction?
A) Full-thickness skin grafting
B) Primary closure
C) Radial forearm fasciocutaneous flap
D) Rectus abdominis musculocutaneous flap
E) Submental artery island flap

C) Radial forearm fasciocutaneous flap

The radial forearm fasciocutaneous free flap is the most appropriate reconstructive choice among those listed. It is generally a thin, pliable flap with a long pedicle and vessels of adequate caliber for straightforward microvascular anastomosis. The physical characteristics of this flap are well-suited to preserving the mobility of the remaining hemitongue, resulting in reasonable speech and swallowing function following surgery in most cases.

The primary goals of reconstruction following hemiglossectomy include watertight wound closure such that oral secretions do not communicate with the neck contents and result in a fistula, and restoration of speech and swallowing function by preserving the mobility of the remaining native tongue. Primary closure would result in severe tongue tethering and impaired speech and swallowing. Although likely to contract less than a split-thickness skin graft, a full-thickness skin graft may also restrict mobility of the tongue and is unlikely to achieve a watertight wound closure. The submental artery island flap is based on a branch of the facial artery that can be used to close defects up to approximately 7 × 18 cm, depending on neck skin laxity. This flap is generally unreliable following neck dissection in which the facial artery and its branches may be ligated. The rectus abdominis musculocutaneous free flap is a highly reliable free flap but is often too bulky to permit optimal mobility of the remaining tongue, especially in patients with truncal obesity.

21

A 13-year-old girl is brought to the office because of a mass of the tongue that has been growing for 10 years. The patient says she has recently noted ulcers from the mass, and bleeding occasionally occurs. Examination of a specimen obtained on biopsy shows a microcystic lymphatic malformation with microthromboses and chronic inflammation. Photographs are shown. Which of the following is the most appropriate management?
A) Embolization
B) Radiation therapy
C) Resection
D) Sclerotherapy
E) Observation only

C) Resection

Resection is the most appropriate management for the symptomatic lesion described in the photographs. Oropharyngeal tumors must always be biopsied to assess malignancy potential. If the tumor is then deemed to be benign, appropriate management is determined based on symptoms. This patient presented with a biopsy result and a sizable lesion that is still growing. Typically, an imaging study such as MRI is performed of the head and neck to assess the extent of the disease. For this type of isolated lesion that is ulcerating and interfering with eating, resection is the most appropriate treatment. Observation is not the best option, as the patient is symptomatic. Embolization is not indicated, as this is not a vascular structure. Sclerotherapy yields poor results with a microcystic lesion and would likely result in painful necrosis of the involved tissue. Radiation therapy is not a described treatment for benign lymphatic lesions.

Carbon dioxide laser treatment has been described for these types of lesions, but it often requires multiple treatments and leaves a raw surface for healing following each treatment.

22

A 65-year-old man is evaluated because of hypernasal speech and nasal regurgitation 12 months after he underwent resection of a soft palate tumor. Examination shows patent nasal passages and no soft palate. Which of the following is the most appropriate treatment?
A) Injection of corticosteroids to the inferior turbinates
B) Placement of an obturator prosthesis
C) Skin grafting
D) Tracheotomy
E) Observation only

B) Placement of an obturator prosthesis

The patient describes velopharyngeal insufficiency post-soft palate resection.

Prosthetic obturation is the traditional means of reconstructing palatal defects. After 12 months, observation has already been performed without resolution of symptoms. Skin grafting of soft palatal defects is of little use because it does not adequately reestablish the bulk necessary for through-and-through palatal defects, therefore leading to contracture and palatal dysfunction. Tracheotomy would exacerbate speech and swallowing difficulties and therefore is not appropriate. Injecting the inferior turbinates with corticosteroids would not functionally correct the velopharyngeal insufficiency and is therefore not appropriate.

23

A 65-year-old woman is scheduled to undergo reconstruction of a total laryngopharyngectomy defect. Use of which of the following is most likely to promote intelligible postoperative tracheoesophageal speech?
A) Anterolateral thigh flap
B) Gastric pull-up
C) Jejunal flap
D) Pedicled muscle flap
E) Pedicled muscle flap

A) Anterolateral thigh flap

When dealing with a near or total circumferential defect of the laryngopharyngeal unit, function must be considered as well as incidence of strictures and fistulas. Many of these patients receive a tracheoesophageal puncture prosthesis (TEP) for speech and many are quite intelligible after rigorous therapy. Speech with fasciocutaneous flaps, such as the anterolateral thigh flap and the radial forearm, is consistently better than with jejunal free flaps. In one study, a direct comparison between these flaps was performed, and 78% of patients used tracheoesophageal speech for conversation when reconstructed with an anterolateral thigh free flap compared with only 25% following a jejunal free flap. The distensibility and mucous production in reconstructions using a jejunal free flap appears to be responsible for the low-pitched, “wet” speech. There is some evidence that intensive speech rehabilitative programs can produce excellent results with jejunal flaps. A pedicled muscle flap is typically used to cover laryngeal or laryngopharyngeal closures, especially in radiation salvage cases. A silastic stent is usually used as salivary diversion while the reconstruction is healing. During its occupancy, no TEP speech can be generated. A gastric pull-up is usually used when a large portion of the cervical esophagus is involved with tumor, and thus a laryngopharyngoesophagectomy is performed so that the anastomosis of the swallowing system is cephalad to the thorax.

24

A 75-year-old man comes to the office because of a squamous cell carcinoma of the lower lip. A wide local excision, removing two thirds of the lower lip extending inferiorly to the chin crease but sparing both oral commissures and bilateral selective neck dissections, is performed. Which of the following is the most appropriate method of reconstruction?
A) Estlander flap
B) Facial artery musculomucosal flap
C) Karapandzic flap
D) Primary closure
E) Radial forearm fasciocutaneous free flap

C) Karapandzic flap

The Karapandzic technique involves performing circumoral incisions, mobilizing the orbicularis oris muscle, and preserving the nerves as well as the vascular supply to the lips from the superior and inferior labial arteries. The advantage of Karapandzic flaps is that they maintain a continuous circle of functioning orbicularis muscle, which helps to restore oral competence. Microstomia can occur, but is usually less of a problem in older patients who have greater tissue laxity.

The optimal method for lip reconstruction depends on the size of the defect, the location of the defect, and the laxity of the remaining tissues. Primary closure can lead to excellent cosmetic and functional results but is restricted to wounds less than one third to one half of the lip width. The Estlander flap is a full-thickness lip transposition flap that borrows tissue from the opposite lip and can be used to reconstruct defects up to two thirds of the lip width. However, the Estlander flap is specifically designed to restore defects of the oral commissure. The Abbé flap is also a transposition flap that “steals” tissue from the opposite lip and is used for central defects, but must remain pedicled by a bridge of lip for several weeks, severely restricting mouth opening during that time. The radial forearm fasciocutaneous free flap is used for total lower lip defects, particularly in situations where sufficient cheek tissue cannot be recruited to close the defect (which is known as the Webster-Bernard technique). Suspension of the folded radial forearm flap over a palmaris longus tendon graft secured to the maxillary bone helps prevent flap ptosis that can result in loss of oral competence, a major problem that can occur with this technique. The facial artery musculomucosal (FAMM) flap is a pedicled flap consisting of buccal mucosa and a portion of the buccinator muscle that can be useful for reconstructing the vermillion lip, but not the cutaneous portion of the lip. Also, because the FAMM flap is based on the facial artery, it may not be reliable following a neck dissection in which the facial artery has been ligated.

25

A 62-year-old woman comes to the office because of skin necrosis and scabbing following a minor injury 6 weeks ago. A photograph is shown. History includes glioblastoma that was treated with craniotomy and radiation therapy 20 years ago. Debridement is performed, exposing the calvaria and dura. Which of the following is the most appropriate treatment for this patient?
A) Bone burring with skin grafting
B) Coverage with acellular dermis matrix
C) Coverage with a free flap
D) Coverage with scalp rotation flaps
E) Negative pressure wound therapy

C) Coverage with a free flap

The patient described has severe radionecrosis of the skin and the underlying bone from the previous radiation therapy. The skin is thinned, and spontaneous necrosis with scabbing can be seen in the photograph and will require extensive debridement including necrotic skin and underlying bone. As a result, closure with scalp rotation flaps will be inadequate because of the extensive skin damage, size of the defect, and exposed underlying dura. Similarly, bone burring will not be possible even if the underlying calvaria was preserved due to the history of radiation. Negative pressure wound therapy is not an option due to exposure of the underlying dura and brain matter. Similarly, acellular dermis will not be effective due to the damaged underlying tissues and chronic contamination. Radical debridement and coverage with a free flap (e.g., latissimus flap) will offer the best option for reconstruction in this patient because this procedure will deliver healthy vascularized tissues to cover the exposed cranial structures.

26

A 65-year-old woman is evaluated immediately after she underwent subtotal maxillectomy for an adenoid cystic carcinoma. The resulting defect includes the right hemi-palate, maxillary sinus, orbital floor, and nasal lining. A photograph is shown. Which of the following is the most appropriate option for reconstruction?
A) Facial artery musculomucosal flap
B) Obturator
C) Omentum flap
D) Rectus flap
E) Temporalis flap

D) Rectus flap

This is an extensive subtotal maxillectomy (Type IIIA Cordeiro classification) that requires reconstruction of a number of anatomical structures including the hard palate, the orbital floor, and the nasal lining. In addition, vascularized tissues are required to separate the maxillary sinus content from the orbit. In this case, the rectus flap is the best option because it can provide skin to re-line the maxillary sinus and repair the palatal defect. In addition, the rectus flap has sufficient bulk to obliterate the maxillary sinus and provide vascularized tissue to support the orbital floor reconstruction that is required. The omentum flap usually has enough bulk to obliterate the sinus but will not enable reconstruction of the palatal defect. The obturator will reconstruct the palate but will not provide vascularized tissue to line the orbital floor reconstruction and separate this region from the maxillary sinus. The temporalis flap can be used to cover the orbital floor reconstruction but does not reconstruct the palatal defect. The facial artery musculomucosal flap is a flap based on the facial artery and would not be useful in this reconstruction.

27

A 64-year-old man with peripheral vascular disease is evaluated because of an oral squamous cell carcinoma that is invading the mandible. On examination, pedal pulses are not palpable. Surgical resection and postoperative radiation therapy are planned. The resulting defect is expected to extend from the left mandibular parasymphysis to the right mandibular mid body. A flap supplied by which of the following arteries is most appropriate for reconstruction?
A) Anterior tibial
B) Circumflex scapular
C) Superficial circumflex iliac
D) Supraclavicular
E) Thoracoacromial

B) Circumflex scapular

The circumflex scapular artery is the blood supply to the scapular bone or osteocutaneous free flap. The pedicle can be extended by including the subscapular artery and vein proximally. This flap can be designed as a chimeric flap to include the latissimus dorsi and serratus anterior muscles based on the thoracodorsal artery, another branch of the subscapular system, to reconstruct complex defects that involve multiple tissue types. The scapular flap can also be based on the angular branch of the thoracodorsal artery. One disadvantage of the scapular flap is that it is on the back, usually precluding simultaneous oncologic resection and flap harvest to save operative time.

Composite bony reconstruction is indicated for the expected mandibular defect. Soft-tissue reconstruction alone for anterior mandibular defects is associated with significant cosmetic deformity as well as impaired masticatory, speech, and even swallowing function. The fibula osteocutaneous free flap, based on the peroneal artery, not the anterior tibial artery, is favored by many surgeons based on its generous bone length and good quality bone stock. However, the flap is contraindicated when blood supply to the distal lower extremity is compromised, such as in advanced peripheral vascular disease (also known as peripheral arterial disease, or PAD). The thoracoacromial artery is the blood supply for the pectoralis major muscle or myocutaneous pedicled flap, which is a soft-tissue flap that would not satisfactorily restore this patient’s appearance and function. An osteomyocutaneous variant of the pectoralis major flap that incorporates the fifth rib has been described, but would not be a first-line option due to limited reach of the flap and the tendency to tether the reconstructed jaw to the neck as scar contracture occurs. The superficial circumflex iliac artery is the blood supply to the groin free flap, which is a soft-tissue flap without a bony component and, therefore, not appropriate for reconstructing the anticipated defect. The supraclavicular artery is the blood supply to the supraclavicular artery island pedicled flap, which is a soft-tissue flap that would be also inadequate to reconstruct this large bony defect.

28

A 37-year-old man sustains a deep laceration of the cheek from a broken bottle resulting in injuries to the facial (VII) nerve and the parotid duct. The nerve is repaired, and the parotid duct is repaired just distal to the masseter muscle over a stent. Treatment with ampicillin-sulbactam is started. Two days later, there is marked swelling and fluctuance in the cheek but no erythema or fever. Which of the following is the most appropriate next step in management?
A) Aspiration and application of compression dressings
B) External incision and placement of a passive drain
C) Intraoral incision and placement of a passive drain
D) Reexploration and revision of the parotid duct repair
E) Reoperation for ligation of the parotid duct proximal to the site of injury

A) Aspiration and application of compression dressings

The patient described has a sialocele, either from a leak at the site of the parotid duct repair or from direct injury to the gland. An abscess is less likely, given the prophylactic antibiotic treatment, no erythema, and no fever. Most occurrences of sialocele after parotid duct injury or repair will resolve with compression with or without repeated aspiration. Anticholinergic medications may help by decreasing salivary flow.

External drainage of a sialocele may result in a fistula and should be avoided. Spontaneous external fistulas after parotid duct repair may be treated with intraoral drainage and compression.

If the sialocele persists, excision of the cyst or pseudocyst may be required, with intraoral drainage over a stent, but this would not be appropriate initial management.

Attempts to revise the parotid duct repair would not likely be fruitful because of postoperative inflammation and unnecessary if an adequate stent were in place and compression were applied.

Ligation is indicated for initial management of proximal injuries to the parotid duct. Significant swelling of the parotid gland will generally occur after this procedure but typically resolves rapidly with atrophy of the gland.

29

Which of the following is characteristic of a Merkel cell tumor of the head and neck?
A ) Arise from minor salivary glands
B ) Higher mortality than malignant melanoma
C ) Rarely metastasize
D ) Treated with radiation therapy alone
E ) Typically involve intraoral structures

B ) Higher mortality than malignant melanoma

Merkel cell tumors are rare neuroendocrine tumors that are highly aggressive. Even despite wide surgical resections, up to one third of patients with Merkel cell tumors have local recurrences. The 5-year mortality rate of Merkel cell tumors is approximately 33%. This is more than double the mortality rate of malignant melanoma (15%). Merkel cell tumors are best treated with wide local excision and sentinel lymph node biopsy. Adjuvant radiation therapy is also used; however, radiation alone is not considered to be the best treatment. Finally, Merkel cell tumors usually arise in sun-damaged skin of the head and neck, not intraoral structures.

30

A 30-year-old woman with cerebral palsy has excessive salivation at rest (unstimulated) that is not controlled with administration of glycopyrrolate (Robinul). Removal of which of the following salivary glands is most likely to reduce salivary flow in this patient?
A ) Minor
B ) Parotid
C ) Sublingual
D ) Submandibular

D ) Submandibular

The parotid and submandibular glands are the main contributors to salivary flow. Minor salivary glands are present in the oral cavity and pharynx. They are minor contributors, creating less than 10% of the saliva. The secretory unit of the salivary glands is constructed of acinar cells, myoepithelial cells, intercalated duct, striated duct, and excretory duct. The acini are responsible for secreting serous and mucous constituents of saliva. The parotid gland is purely a serous-secreting gland, whereas the submandibular is predominately serous, with 10% of the acinar cells producing mucous secretions. In the unstimulated state, the submandibular gland produces most of the saliva, whereas the parotid gland is responsible for most of the saliva produced in the stimulated state. Total salivary flow can reach 1.5 L daily in healthy individuals.

Xerostomia is a common complication resulting from radiation therapy for head and neck cancer. Xerostomia is defined as dry mouth (reduced or absent saliva flow) caused by damage to the salivary glands. Xerostomia has late effects on oral health, specifically dry mouth, sore throat, altered taste, dental decay, changes in voice quality, and impaired chewing and swallowing function. Xerostomia may also contribute to the development of mandibular osteoradionecrosis after radiation.

Salivary flow reduces to 50 to 70% of baseline after 10 to 16 Gy radiation and is undetectable after 40 to 42 Gy radiation. Xerostomia has been reported to occur in 60 to 90% of survivors of head and neck cancers treated with radiation therapy.

Management of xerostomia is focused on prevention and treatment. Although there are multiple options and advances that have been made in the management of this condition, there are no specific regimens that will prevent or completely treat xerostomia. Prevention of xerostomia includes cytoprotection using amifostine or pilocarpine. Radiation therapy techniques that spare the salivary gland may be more effective than cytoprotective agents. Such techniques include the use of intensity-modulated radiation therapy to spare the parotid gland and submandibular gland. Surgical submandibular gland transfer has also been described. Treatment of radiation-induced xerostomia includes salivary substitutes, salivary stimulants, acupuncture, and gene therapy.

31

A 32-year-old man comes to the office because he has had painless swelling of the right side of the jaw for the past 4 months. Examination shows a 6-cm mass over the mandibular angle. Panoramic x-ray study (Panorex) of the mouth is shown. Examination of the specimens obtained on biopsy of the lesion shows palisading odontogenic cells. Which of the following is the most appropriate management?
A ) Curettage and cancellous bone graft
B ) Curettage only
C ) Induction chemotherapy followed by irradiation
D ) Segmental resection and immediate reconstruction with a vascularized bone graft
E ) Segmental resection and nonvascularized bone graft

D ) Segmental resection and immediate reconstruction with a vascularized bone graft

This patient has an ameloblastoma, which is a rare cystic tumor involving the mandible. Characteristic findings include a multilocular radiolucent lesion with a ?soap bubble? appearance, usually in association with an impacted molar. X-ray studies show unilocular or multilocular cystic masses associated with thinning of the surrounding bone. Examination of a biopsy specimen shows palisading odontogenic cells.

Appropriate treatment consists of segmental mandibular resection, including a margin of normal bone and any adjacent teeth, and immediate reconstruction. Immediate reconstruction will rapidly restore facial function and improve facial aesthetics. Curettage is inadequate and is associated with a recurrence rate of 50 to 100%.

Ameloblastomas are generally benign. Malignant forms of ameloblastoma may occasionally be treated with adjuvant radiation therapy in addition to surgical resection.

32

An 18-year-old woman is referred for evaluation because of bulging of the right upper eyelid that has progressed slowly for the past 6 years. Physical examination shows soft enlargement of the right upper eyelid with ptosis; skin color shows no abnormalities and vision is preserved. CT scan shows no intraorbital, intracranial, or bony involvement. Examination of a specimen obtained on biopsy shows spindle cells and mast cells in a collagenous myxoid stroma. Which of the following is the most likely diagnosis?
A ) Cobb syndrome
B ) Fibrous dysplasia
C ) Klippel-Trénaunay syndrome
D ) Neurofibroma
E ) Sturge-Weber syndrome

D ) Neurofibroma

These orbitofacial tumors may be part of a syndrome of neurofibromatosis 1 (NF1), which is an autosomal dominant disorder. When the full syndrome is present, skeletal dysplasia such as absence of the greater wing of the sphenoid (5 to 7%) and macrocephaly may be present. However, solitary neurofibromas unassociated with other features are not uncommon. There are three subtypes of neurofibromas: localized, plexiform, and diffuse. About 30% of plexiform neurofibromas outside of the central nervous system are associated with NF1, and the remainder are isolated. The tumors of NF2 are nearly all confined to the central nervous system and are similar to schwannomas. The scenario describes a case of plexiform neurofibroma. The majority of plexiform neurofibromas are present at birth, and half are found in the head and neck region. These tumors tend to grow in the prepubescent ages as a result of hormonal stimuli. Pathology is distinctive, and there is a 13% rate of malignant transformation. Surgical debulking and reconstruction remains the best treatment option.

Cobb syndrome consists of a capillary malformation in the midline scalp region overlying an encephalocele, or in the skin posterior to an area of dysraphism in the cervical or lumbosacral spine. It does not involve the face or orbit.

Fibrous dysplasia is an overgrowth syndrome of bones only, due to abnormal proliferation of bone-forming mesenchyme. It does not involve soft-tissue hypertrophy, nor is it associated with vascular malformations. Albright syndrome is a specific variety of polyostotic fibrous dysplasia and includes endocrine abnormalities and café-au-lait spots.

Klippel-Trénaunay syndrome is a capillary-lymphatic-venous malformation typically involving hypertrophy of the extremities and sometimes the thorax of one side of the body, and does not involve the head and neck. The skin surface shows deep red staining with hemolymphatic vesicles. A pathognomonic feature of this condition is the presence of the embryonal lateral vein of Servelle in the lower extremity. Parkes-Weber syndrome is similar to Klippel-Trénaunay syndrome in that it may be confined to an upper or lower extremity. Overgrowth of the extremity is characteristic along with microscopic arteriovenous fistulas, and unlike Klippel-Trénaunay, lymphatic anomalies are rare. It does not involve the head or neck.

Sturge-Weber syndrome is characterized by capillary malformations in the distribution of the ophthalmic or the maxillary division of the trigeminal nerve, and may be unilateral or bilateral. Frequently, there is also gradual enlargement and hypertrophy of the cheek, lip, maxilla, and occasionally the mandible. MRI may show additional vascular anomalies of the leptomeninges and choroid plexus.

33

Which of the following best approximates the 3-year survival rate of osseointegrated dental prostheses used in reconstruction with a nonirradiated free fibula flap?
A ) 5%
B ) 25%
C ) 50%
D ) 75%
E ) 95%

E ) 95%

Osseointegrated prostheses are currently used to anchor dental crowns, auricular and facial prosthetics, and hearing aids (bone-anchored hearing aids, or BAHAs). This technology has improved since it was first introduced, and long-term survival rates are generally good. Several studies have confirmed short to intermediate survival rates of around 95% for dental prostheses in nonirradiated free fibula flap reconstruction. The results are significantly worse in irradiated tissues.

34

A 75-year-old man is scheduled to undergo a 5-cm composite resection including selective neck dissection and adjuvant radiation therapy because of a floor-of-mouth squamous cell carcinoma that is invading the anterior mandible. History includes hypertension. He had smoked a pack of cigarettes daily for 50 years and quit 8 years ago. He has no other cardiac risk factors and walks a mile daily. Which of the following is the most appropriate reconstruction to maximize this patient?s postoperative function?
A ) Iliac crest bone grafting
B ) Reconstruction with a 2.0-mm titanium plate and coverage with a pectoralis major musculocutaneous pedicled flap
C ) Reconstruction with a fibula osteocutaneous free flap
D ) Reconstruction with a radial forearm fasciocutaneous free flap
E ) Reconstruction with a supraclavicular island pedicled flap

C ) Reconstruction with a fibula osteocutaneous free flap

Failure to reconstruct the anterior mandibular bone results in the so-called ?Andy Gump? defect and is associated with disfigurement, as well as impaired speech, swallowing, and mastication. Of the choices listed, the fibula osteocutaneous free flap is the most reliable reconstruction of the anterior mandible, particularly when radiation therapy is administered. The fibula provides a large amount of good-quality bone stock than can tolerate osteotomies, which are needed to restore the shape of the anterior mandible. A skin paddle based on perforating vessels from the peroneal artery can be included to simultaneously reconstruct the floor-of-mouth mucosal defect. Age alone is not a contraindication to reconstruction with a microvascular free flap, provided the patient is in otherwise good medical condition and has patent blood circulation to his distal lower extremity.

A nonvascularized iliac crest bone graft can be used to reconstruct small mandibular defects (under 5 cm in length), but will most likely not tolerate radiation, so it would not be a good option in this case.

Mandibular reconstruction with a titanium plate, alone or covered with a soft-tissue flap, such as the pectoralis major myocutaneous pedicled flap, is associated with a very high rate of complications, including infection, exposure, and plate fracture, particularly in the setting of an anterior location and radiation therapy.

The radial forearm fasciocutaneous free flap can be used to close the floor-of-mouth mucosal defect, but will not restore the bony mandible.

The supraclavicular island pedicled flap is based on the supraclavicular artery, a branch of the transverse cervical artery, and can be used to close oral soft-tissue defects, but, like the radial forearm fasciocutaneous free flap, will not restore the mandible.

35

A 45-year-old man is scheduled to undergo reconstruction after resection of an adenoid cystic carcinoma. An intraoperative photograph is shown. Closure of the palate, support of the orbit, and contour for the cheek are planned. Which of the following is the most appropriate reconstructive procedure?
A ) Free dorsalis pedis flap coverage with vascularized toe
B ) Free radial forearm flap coverage with vascularized radius
C ) Free rectus abdominis flap coverage and iliac crest bone grafting
D ) Pedicled pectoralis flap coverage with vascularized rib
E ) Pedicled temporalis flap coverage with vascularized split calvarial bone flap

C ) Free rectus abdominis flap coverage and iliac crest bone grafting

Reconstruction of mid face defects after oncologic resection is challenging. The defect described involves a large portion of the mid face with resection of the hard palate and orbital floor (Cordeiro type IIIb). Therefore, reconstruction should aim to provide closure of the palate, support for the orbit, and contour for the cheek. Of the choices given, the free rectus abdominis flap with iliac crest bone graft is the most appropriate option because it provides volume for reconstruction of the maxillary defect, closure of the palatal defect, and support of the eye structures with an iliac crest bone graft.

The dorsalis pedis flap is not an appropriate choice because of its low volume and donor site defect.

The free radial forearm flap lacks sufficient volume to reconstruct this extensive defect of the mid face.

The pedicled pectoralis flap does not reach this mid face defect reliably.

The pedicled temporalis flap with vascularized split calvarial bone flap similarly does not reach this defect because of its short arc of rotation.