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Flashcards in Skin and Soft Tissue Deck (63):

Describe the normal anatomy and histology of the skin.

  • layers
  • adnexal structures
  • glands and their locations

Normal skin includes dermal and epidermal layers as well as adnexal structures such as sweat glands (apocrine and eccrine), hair follicles, and sebaceous glands. Apocrine sweat glands, found primarily in the axilla, groin, and perineum, produce a cloudy, thick sweat associated with bacterial overgrowth and body odor, whereas eccrine sweat glands found on the rest of the body produce normal sweat to aid in temperature regulation.


Basal cell carcinoma arises from...

...the basal cells in the innermost layer of the epidermis. These are the cells that continually divide to form the outer layers of the epidermis.


Squamous cell carcinoma also arises from what layer of the skin...

Precursor lesion? the epidermis but develops from squamous cells, which are keratin-producing.

Actinic keratosis, an overgrowth of keratinocytes, is a known precursor lesion for development of squamous cell carcinoma.


Dermatofibrosarcoma protuberans is a cutaneous soft tissue sarcoma arising from...

...fibroblasts within the dermis. These tumors, which have a dermal origin, usually have a covering of epidermis.


Cutaneous adnexal tumors are a wide variety of benign and malignant neoplasms that arise from...

Contrast benign and malignant types.

... sweat glands, hair follicles, and sebaceous glands.

Benign tumors are usually multilobulated and smooth-bordered, and histologically they have low mitotic rate, normal nuclei, and no ulceration.

In contrast, malignant tumors are more likely to be irregular and asymmetric, and they have high levels of nuclear atypia, a high mitotic rate, and ulceration.


Merkel cell carcinoma is traditionally believed to arise from... 

...neuroendocrine cells in the epidermis which function as mechanoreceptors, although some researchers believe that these tumors arise from stem cells which only later take on the neuroendocrine morphology.


Basal cell carcinoma is the most common type of skin cancer and makes up about 80% of nonmelanoma skin cancers. About 20% of Americans will develop nonmelanoma skin cancer in their lifetime. Risk factors for developing basal cell carcinoma incude... 

...ultraviolet light exposure; older age; fair skin; smoking; exposure to organic hydrocarbons, arsenic, or ionizing radiation; and immunosuppression.

Typically, the sun exposure has been intermittent and intense rather than chronic and moderate.


Squamous cell carcinoma is the second most common skin cancer, making up approximately 20% of nonmelanoma skin cancers. Risk factors for developing squamous cell carcinoma, which are similar to the risk factors for developing basal cell carcinoma, include... 

... prolonged ultraviolet light exposure, older age, fair skin, nonhealing wounds with chronic inflammation, smoking, chemical and radiation exposure, and human papilloma virus infection.

Most common type of skin cancer seen in transplant patients.


Dermatofibrosarcoma protuberans epidemiology 

rare nonmelanoma skin cancer, with fewer than 5 cases per million per year. It presents more commonly in younger patients (average age at diagnosis, mid-30s) and is more common in African Americans than Caucasians.


Cutaneous adnexal tumors epidemiology

Rare. Malignant cutaneous adnexal tumors typically present in older patients with a median age of 70 years, whereas benign lesions more commonly present in the fourth to sixth decades of life.


Merkel cell carcinoma epidemiology

  • Rare tumor, with about 6 cases per million per year in the US.
  • Present in older pts with a median age at presentation of  70.
  • Risk factors for developing Merkel cell carcinoma: UV light, fair skin,  immunosuppression, which is a critical risk factor, and a history of leukemia and lymphoma.
  • Merkel cell polyomavirus seems to play a role in the tumorigenesis of most Merkel cell carcinomas, although many patients who carry the virus do not go on to develop Merkel cell carcinoma.


The history of the nonmelanoma skin lesion itself should focus on...

...time course, growth, prior trauma to the area, history of previous similar lesions, associated symptoms such as pruritus or pain, and any previous treatments or procedures in the area.


Exposure history should focus on... 

...known risk factors for skin cancer, with a particular emphasis on sun exposure (occupational or recreational), tanning bed use, and radiation or chemical exposure. In addition, patients with a history of prior skin cancers are at an increased risk for subsequent skin cancers.


In addition to careful examination of the nonmelanoma skin lesion itself, the physical examination should note:

  • The presence of any abnormalities of the surrounding skin (such as satellite lesions)
  • The presence or absence of ulceration
  • Whether the lesion is fixed to underlying structures
  • Draining lymph nodes


Several adnexal skin tumors, which are rare in the general population, may be common in patients with certain genetic syndromes such as,..

Brooke-Spiegler syndrome, Birt-Hogg-Dubé syndrome, Muir-Torre syndrome, Cowden syndrome, familial cylindromatosis, and multiple familial trichoepithelioma.


Squamous cell carcinoma physical exam

  • arises in a background of actinic keratosis—scaly and erythematous lesions in sun-damaged areas
  • the squamous cell carcinoma itself is often ulcerated with raised edges.


Basal cell carcinomas physical exam

  • have some diversity in appearance and come in nodular, cystic, superficial, micronodular, and morpheaform patterns
  • most commonly, they are raised, well-circumscribed, and waxy, classically with “rolled” or “pearlescent” edges.


Dermatofibrosarcoma protuberans typically presents... 

  • initially as a plaque or nodule covered with skin, which may initially be normal
  • more advanced tumors will be larger and more protuberant and more typically demonstrate overlying skin changes


Cutaneous adnexal tumors typically present with... or skin-colored nodules less than a few centimeters in size. Ulceration may indicate malignancy.


Merkel cell carcinoma typically presents as...

...a firm bump within the skin which grows quickly and is typically a red/purple nodule without ulceration.


Determine the appropriate technique of biopsy of a suspicious skin lesion (types of biopsies).

Punch biopsy.

Performed under local anesthesia, a full-thickness sample of the tumor ideally with a border of normal surrounding skin.


Extra workup?

  • dermatofibrosarcoma protuberans with fibrosarcomatous
  • higher risk Merkel cell carcinoma

  • Chest CT to evaluate for distant metastasis.
  • Merkel cell carcinoma has a high propensity to metastasize, and staging PET scan or CT scans should be considered in higher risk cases. 


Basal cell carcinoma and squamous cell carcinoma should usually be excised with margins of... 

... 4 to 10 mm, depending on tumor risk profile.


Dermatofibrosarcoma protuberans should usually be excised with wide margins of... 

2 to 4 cm because rates of local recurrence are higher with narrower margins.


Cutaneous adnexal tumors that are benign may undergo what type of excision?

If these tumors are malignant, they should be...

  • Simple excision if they are symptomatic or cosmetically undesirable, but they may be observed in some cases, depending on histology.
  • ... widely excised w/ 1 - 2 cm margin, consider SLNBx


Merkel cell carcinoma operative approach?

should be widely excised with 1 to 2 cm margins

consider SLNBx (high rate of nodal mets)


Sentinel lymph node biopsy in nonmelanomatous skin cancers 

  • What situations warrant SLNBx?
  • What if biopsy is positive? 
  • What if clinically apparent lymph node disease?

SLNBx not routine for many types of nonmelanoma skin cancers

  • High-risk SCC, malignant cutaneous adnexal tumors, MCCa
  • Completion lymphadenectomy considered with positive SLNBx
  • Clinically apparent LN dz may benefit from a therapeutic lymphadenectomy


Mohs surgery relies on serial frozen section analysis of margins and for specific types of nonmelanoma skin cancer may permit comparable oncologic outcomes without the need for large tissue defects. What situations warrant its use? 

It is considered for specific types of skin cancers such as basal cell carcinoma and squamous cell carcinoma, particularly for tumors on the head or neck, or for tumors in which reconstruction of a large tissue defect is impractical.


Premalignant lesions such as actinic keratosis nonop management option

Topical therapies such as imiquimod or 5-fluorouracil may be used in some cases


Low-risk, small, squamous cell carcinomas or basal cell carcinomas are sometimes successfully treated with... 

cryotherapy, laser ablation, or electrodesiccation


A 75-year-old man, a retired highway worker, presents to your office with a raised and ulcerated plaque on his left cheek. It has been present and gradually growing for the past 6 months. How would you work up this patient? What will your management be?

  • Suspicious for cutaneous squamous cell carcinoma, maintain a broad differential diagnosis (basal cell carcinoma, atypical melanoma, and cutaneous adnexal tumor)
  • Punch biopsy is test of choice after H&P
  • If the patient is an appropriate candidate based on histologic type of tumor (eg, squamous cell carcinoma or basal cell carcinoma) and clinical parameters, Mohs surgery should be considered in lieu of traditional wide local excision, given the location of the lesion (on the face).


A 40-year-old African American man in good health presents to your office for consultation after biopsy of a raised lesion on his left flank comes back as dermatofibrosarcoma protuberans. How do you manage this case? How would your management change if the pathologist’s report also noted fibrosarcomatous change?

  • Wide excision w/ 2-4cm margins, high rate of local recurrence. 
  • Fibrosarcomatous change on pathology should trigger a more extensive staging workup, such as CT scan of the chest, because these tumors are much more likely to metastasize. High-risk may benefit from adjuvant or neoadjuvant therapy.


You see a 62-year-old woman in your office for her postoperative visit after removing a 2-cm basal cell carcinoma from her right shoulder. She would like to know why she developed this tumor and what she can do to prevent another one from occurring. What do you tell her?

The most important modifiable risk factor for nonmelanoma skin cancer is sun exposure.

Potentially modifiable risk factors for nonmelanoma skin cancer include occupational chemical or radiation exposure, chronic wounds, and smoking.

Nonmodifiable risk factors include immunosuppression, age, and skin type.


A 77-year-old white male presents to your office with a firm 1-cm intradermal nodule on his left shoulder which has been growing quickly. Punch biopsy is performed and pathology reveals nests of small blue cells. What is the likely diagnosis and how will you manage and counsel this patient?

  • Merkel cell carcinoma.
  • Wide local excision with 1-2 cm margins and often sentinel lymph node biopsy.
  • Pre-operative staging w/ PET or CT scans based on risk profile.
  • Adjuvant radiation may be considered, relatively high rates of recurrence.
  • The recurrence rate for Merkel cell carcinoma is relatively high, and patients require frequent follow up and surveillance.


Targeted therapies such as vismodegib can be used in what type of skin cancer when it has become metastatis?

basal cell carcinoma


Epidermal growth factor antagonists or tyrosine kinase inhibitors can be used for what skin cancer if it has become metastatic?

squamous cell carcinoma


                    has shown some efficacy in locally advanced or metastatic dermatofibrosarcoma protuberans



                   is a therapeutic option for patients who develop distant metastases from Merkel cell carcinoma.



Adjuvant radiation therapy may be used in which settings in regards to skin cancer 

dermatofibrosarcoma protuberans, in high-risk cases, with positive margins in which additional surgery is not feasible

the resection bed or nodal basin in Merkel cell carcinoma

may be considered as the primary therapy for patients with Merkel cell carcinoma who cannot undergo appropriate resection due to comorbidities


Albinism or xeroderma pigmentosum are associated with development of what types of skin cancers?

Sun-related cancers such as basal cell or squamous cell carcinoma.


Individuals with                  may develop dozens of basal cell carcinomas as well as bony cysts, medulloblastoma, and craniofacial abnormalities, a disorder known as basal cell carcinoma syndrome.

germline mutations in the PTCH1 gene


Determine the appropriate technique of biopsy of a suspicious skin lesion (types of biopsies).

Excisional biopsy

Excisional biopsy removes the entire lesion in the initial specimen. Care must be taken in the initial approach (eg, orientation of wound and amount of tissue removed) to plan for a potential reexcision in case the final pathology requires definitive surgical treatment.


Determine the appropriate technique of biopsy of a suspicious skin lesion (types of biopsies).

Core needle biopsy or incisional biopsy

Core needle biopsy or incisional biopsy may be considered in patients who have deeper or larger tumors such as dermatofibrosarcoma protuberans.


Determine the appropriate technique of biopsy of a suspicious skin lesion (types of biopsies).

Shave biopsy

Shave biopsy is often inadequate for differentiating between the various entities under consideration when working up a potential cutaneous malignancy.


Determine the appropriate technique of biopsy of a suspicious skin lesion: reason/use for histologic analysis.

Routine histologic analysis provides some information about the architecture and possible cellular lineage of the tumor, but special stains or even genetic analysis may help distinguish among some types of tumors. These are particularly useful in cases of cutaneous metastases from nonskin cancers.


Risk factors for surgical site infection:

  • patient: age, obesity, DM, low nutrition, radx, low O2
  • environmental: poor sterilization, ventilation
  • treatment: emergent procedures, prolonged OR time, inadequate abx


What are the 4 wound classes?

  1. clean - no entry of respiratory, GI, GU tracts; no inflammation
  2. clean contaminated - entry of respiratory, GI, GU tract w/ minimal spillage; no infected fluids; minor break in technique
  3. contaminated - gross spillage of infected fluid from respiratory, GI, GU tracts; fresh trauma; major break in technique
  4. dirty - acute bacterial inflammation, devitalized tissue, FB, fecal contamination, delay in treatment


How can you optimize patient factors in a pre-op patient the day before and day of surgery to prevent surgical site infections?

  • patient should bathe fully the night before
  • alcohol-based prep unless contraindicated
  • remove hair with clippers
  • control glucose
  • control temperature


What three factors determine prophylactic antibiotic choice in elective procedures?

  • type of surgery
  • antibiotic allergies
  • presence of MRSA


Control glucose in postop patients between what levels?


140 - 180

>200 increases risk of SSI


How is SSI diagnosed?

  • the diagnosis is clinical
  • vitals: can have tachycardia, tachypnea, or fever
  • exam: erythema, induration, fluctuance, warmth
  • labs: elevated WBC, elevated bands
  • cultures are not required for dx, but may aid in abx tailoring in deep or organ space level infections


Given a patient with an organ/space SSI, manage the patient.

  • ABC - resuscitate if necessary
  • Obtain blood cultures
  • Broad spec abx - zosyn, mero, cefepime+flagyl
  • IR drainage vs open - source control + cultures
  • Continue abx 4 days after surgically cleared


A 78-year-old man with a history of diabetes and hypertension is about to undergo a left colectomy for colon cancer. How will you prepare him for surgery?

  • bathe night before
  • postop glucose control
  • ppx abx (ancef + flagyl, vanc + levaquin), bowel prep
  • clippers, avoid hypothermia, alcohol skin prep


One week after laparoscopic appendectomy, a 28-year-old woman comes to your office complaining of diarrhea, fever, and lower abdominal pain. What will you do?

  • possible pelvic abscess
  • rectal/pelvic exam
  • labs, CT abd/pelvis
  • zosyn + drain


How does a pilonidal abscess typical present?

erythema, tenderness, fluctuance, drainage at the intergluteal cleft


Does the abscess in pilonidal disease have an epithelial lining? What is contained in the abscess?

No. It is a subcutaneous abscess filled with hair, debris, and purulent material.


How is a pilonidal sinus different from a pilonidal abscess?

The sinus is a tract draining cranially and laterally from the cleft in the setting of chronic pilonidal disease. 


Describe the management of a pilnidal abscess?

Outpatient I&D with a paramidline incision, soak in warm tub multiple times/day.


Describe the management of a pilonidal sinus.

Outpatient unroofing - use a probe and direct it into the lowest portion of the sinus. Use electrocautery to open sinus over the probe. Connect all pits and sinuses. Curette tract to remove debris and marsupialize the edges of the wound. 

The tract can also be excised down to sacrococcygeal fossa and primarily closed if no infection/contamination or can be left open and packed. If the tract is large, you can flap over the wound. The goal of the flaps is to make the intergluteal cleft more shallow. 


Dictate the a pilonidal sinus excision. 

The patient was identified in preop, consent and procedure confirmed, then taken to the OR. General anesthesia was induced, and the patient was placed in the prone position. The patient was prepped and draped in the standard fashion (buttocks spread and held open with adhesive tape) and a timeout was called. The planned paramidline elliptical incision was made to include all of the sinus, including the lowest portions. The tissue was excised down to the sacral fascia. Because there was no infection or debris encountered, the resulting wound was closed layers.


What counseling for the nonoperative portions of management can you provide a patient with pilonidal disease?

  • keep hair short
  • perineal hygiene is important
  • laser hair-removal can provide long-lasting hair removal

the above results in fewer hospital admissions and surgical procedures for this population


Comment on the postop course of pilonidal disease?

wounds often break down and reoperation rate is around 50%; healing takes a long time