(A) Morpheaform
(B) Nodular
(C) Pigmented
(D) Ulcerated

The correct response is Option A.

Mohs’ micrographic resection involves serial excision of the visible tumor in layers of increasing depth followed by immediate microscopic examination of the excised tissue. A map of the specimen is created and divided into sections; the presence of tumor in a certain section necessitates further excision in that section only. Serial excision continues until there is no longer any microscopic evidence of tumor. Cure rates for this technique, when used for treatment of basal cell carcinoma, have been reported to range from 98.2% to 99.9%, compared with 94% to 95% for standard surgical excision.

Mohs’ micrographic resection is appropriate for removal of basal cell carcinomas, especially recurrent lesions and those lesions that are located in anatomically sensitive sites, such as the eyelid margin, medial canthus, and nasal ala. This technique is particularly effective for the morpheaform variation of basal cell carcinoma, also know as sclerosing basal cell carcinoma, because of the difficulties encountered when attempting to visually determine the tumor margins, which are often not well demarcated. In addition, because morpheaform basal cell carcinoma is more prone to recur, pathologic evaluation of the margins is indicated prior to reconstruction.

Because nodulated, pigmented, and ulcerated basal cells typically have distinct margins and are amenable to primary excision, Mohs’ micrographic resection is usually unnecessary.

References
1. Olbricht SM. Cutaneous carcinomas. In: Georgiade GS, Riefkohl R, Levin LS, eds. Plastic, Maxillofacial and Reconstructive Surgery. Baltimore, Md: Williams & Wilkins; 1997:126-127.
2. Robins P. Mohs’ micrographic surgery. In: McCarthy JG, ed. Plastic Surgery. Philadelphia, Pa: WB Saunders Co; 1990;7:3652.

Which of the following medications is most appropriate to prevent and to treat heterotopic ossification?

(A) Calcitonin
(B) Etidronate
(C) Mithramycin
(D) Phosphate

The correct response is Option B.

Heterotopic ossification is an abnormal proliferation of bone that occurs in patients who have sustained burns, spinal cord injuries, and closed head trauma. This condition becomes apparent initially on radiographs one to four months after injury. It may occur in up to 40% of patients who sustain spinal cord injuries and is clinically significant in one-half of those patients.

Etidronate (Didronel) and pamidronate (Aredia) are most appropriate for prevention or treatment of heterotopic ossification. These agents act primarily on bone to inhibit the formation, growth, and dissolution of hydroxyapatite crystals and do not impair fracture healing.

Calcitonin, mithramycin, and phosphate decrease serum calcium levels and do not directly affect heterotopic ossification.

References
1. Donelan MB. Reconstruction of the burned hand and upper extremity. In: McCarthy JG, ed. Plastic Surgery. Philadelphia, Pa: WB Saunders Co; 1990;8:5473-5476.
2. Hotchkiss RN. Elbow contracture. In: Green DP, et al, ed. Operative Hand Surgery. New York, NY: Churchill Livingstone, Inc; 1999;1:668-669, 679-681.
3. Physicians’ Desk Reference. Montvale, NJ: Medical Economics Co; 2003:2825.

A 55-year-old man has a lesion on the right forearm that has enlarged over the past six weeks. A photograph is shown above. Which of the following is the most likely diagnosis?

(A) Cylindroma
(B) Dermatofibroma
(C) Keratoacanthoma
(D) Seborrheic keratosis
(E) Syringoma
The correct response is Option C.

The most likely diagnosis is keratoacanthoma, a common cutaneous neoplasm that typically occurs in men older than age 50 years. Keratoacanthomas grow rapidly over several weeks and are believed to regress spontaneously if left untreated. They are characterized by an umbilicated center with a keratin plug. Because they are difficult to distinguish from squamous cell carcinoma and may indeed be linked, excision for histopathologic confirmation is recommended.

Cylindromas are round, firm, fleshy tumors of the scalp that are rarely solitary.

Dermatofibroma is a fibrous, papular lesion characteristically found on the lower extremities in young adults.

Seborrheic keratosis has a waxy, greasy, or pressed-on appearance and generally occurs on the face and trunk of older persons.

Syringoma is a flesh-colored or yellow papule that typically develops in females during adolescence or early adulthood. These lesions may be multiple and often occur only on the lower eyelids.

References
1. Gasparro FP. P53 and dermatology. Arch Dermatol. 1998;134:1029-1032.
2. Harris AO, Levy ML, Goldberg LH, et al. Nonepidermal and appendageal skin tumors. Clin Plast Surg. 1993;20:115-130.
3. Owen C, Telfer N. Keratoacanthoma. In: Lebwohol MG, ed. Treatment of Skin Disease: Comprehensive Therapeutic Strategies. Philadelphia: Mosby Year - Book, Inc; 2002:315.

A 51-year-old woman has had multiple lesions around the nostrils for the past two years. She says that the lesions first appeared similar to pimples and have enlarged. A photograph is shown above. The lesions have not resolved with intralesional injections of corticosteroids. Findings on nasal smear and tissue cultures are negative. Histologic examination of a biopsy specimen of a lesion shows noncaseating epithelioid granulomata.

Which of the following is the most likely diagnosis?

(A) Cutaneous sarcoidosis
(B) Keloids
(C) Neurofibromatosis
(D) Rhinosporidiosis
(E) Wegener’s granulomatosis

The correct response is Option A.

In this 51-year-woman who has the findings shown in the photograph, the most likely diagnosis is cutaneous sarcoidosis. This condition occurs in 10 Caucasians and 35 African Americans per 100,000 of population. Although sarcoidosis typically affects the lungs and intrathoracic lymph nodes, cutaneous symptoms, such as maculopapular eruptions, sarcoidal plaques, lupus pernio lesions, and subcutaneous and cutaneous nodules, occur in 25% of patients. Histologic examination of a biopsy specimen of affected skin shows noncaseating granulomata and aggregates of epithelioid cells and giant cells containing Schaumann (asteroid bodies) within the dermis.

Appropriate treatment of cutaneous sarcoidosis is intralesional administration of a corticosteroid or oral administration of hydroxychloroquine sulfate or methotrexate. Oral corticosteroids are reserved for patients with severe cutaneous disfigurement or symptomatic involvement of internal organs. Surgical options are limited because of the systemic nature of this condition.

In patients with keloids, histologic examination shows extensive fibrous tissue with scattered collagen fibers but without a definite architecture or a granulomatous pattern.

Neurofibromatosis is characterized histologically by swirls of fibroblastic cells, collagen, and nerve fibers. Granulomas are not present.

Rhinosporidiosis is a fungal granulomatous condition of the nose caused by Rhinosporidium seeberi bacteria. Affected patients have pedunculated masses with reddish-purple discoloration. Although findings on culture are usually negative, microscopic examination of nasal smears typically shows sporangia.

Wegener’s granulomatosis is a systemic disease that initially causes localized perforation of the septum or multiple intranasal ulcerations. Histologic examination shows findings consistent with necrotizing granulomatous vasculitis.

References
1. Cody DT, DeSanto LW. Neoplasms of the nasal cavity. In: Cummings CW, Fredrickson JM, Harker LA, et al, eds. Otolaryngology Head and Neck Surgery. 3rd ed. Saint Louis, Mo: Mosby Year - Book, Inc; 1998;2:883-901.
2. Landau M, Mevorah B. Cutaneous manifestations of systemic diseases. In: Parish LC, Brenner S, Ramos-e-Silva M, eds. Women’s Dermatology – From Infancy to Maturity. Pearl River, NY: The Parthenon Publishing Group; 2001:243-250.
3. Weedon D. The granulomatous reaction pattern. In: Weedon D, ed. Skin Pathology. 2nd ed. London, England: Churchill Livingstone; 2002:193-209.

A 46-year-old woman has had painful purpura-like lesions on the breasts, abdomen, and lower extremities for the past three weeks. She currently undergoes dialysis for end-stage renal disease. Physical examination shows several dry, leathery, full-thickness areas of skin necrosis. A photograph is shown above. Calciphylaxis is diagnosed.

Laboratory studies are most likely to show an increased serum level of which of the following?

(A) Calcium
(B) Glucose
(C) Parathyroid hormone
(D) Protein C
(E) Thyroid-stimulating hormone

The correct response is Option C.

Calciphylaxis, also known as uremic gangrene syndrome, is a rare complication of end-stage renal disease. This condition is characterized by painful, ischemic, violaceous skin lesions on the extremities and sometimes the trunk that exhibit a livido reticularis pattern. Full-thickness skin necrosis ensues, leading first to secondary infection, then to sepsis, and frequently to death; the mortality rate in patients with calciphylaxis has been reported to be as high as 60%. Histologic examination of affected skin shows fat necrosis, calcification of the subcutaneous tissues, and microcalcifications in the intima and media of small arteries. Luminal narrowing of the vessels with intimal hyperplasia is common, and complete occlusion also occurs.

Calciphylaxis is a result of the metabolic imbalance in calcium and phosphate homeostasis that is frequently observed in patients with renal failure. Secondary hyperparathyroidism causes an abnormal increase in calcium X phosphate product, which can lead to soft-tissue calcification. In these patients, serum levels of parathyroid hormone are most likely to be increased. Hyperphosphatemia is also characteristic.

The lesions that occur in patients with calciphylaxis rarely heal spontaneously and frequently become infected. Therefore, various management options should be considered, including debridement of the lesions, topical administration of antimicrobial agents, and frequent dressing changes, followed by skin grafting, or direct excision and closure of the lesions. However, in this patient, the dry, leathery composition of the affected skin suggests that infection has not yet developed. Subtotal thyroidectomy is also advocated for treatment in some patients.

Although hypercalcemia may be present, serum calcium levels are normal in most patients with this condition.

Many patients with end-stage renal disease also have diabetes mellitus, but hyperglycemia is not typically associated with calciphylaxis.

A deficiency of, and not an increase in, serum protein C levels has been proposed to be a contributing factor to tissue death in these patients because it causes thrombosis in small vessels.

Increased serum levels of thyroid-stimulating hormone occur in patients with hypothyroidism.

References
1. Burkhart CG, Burkhart CN, Mian A. Calciphylaxis: a case report and review of the literature. Wounds. 1999;11:58-61.
2. Kane WJ, Paetty PM, Sterioff S, et al. The uremic gangrene syndrome: improved wound healing in spontaneously forming wounds following subtotal parathyroidectomy. Plast Reconstr Surg. 1996;98:671-678.
3. Senturk S, Hosnuter M, Tosun Z, et al. Calciphylaxis: cutaneous necrosis in chronic renal failure. Ann Plast Surg. 2002;48:104-105.

Which of the following pigmented nevi is classified as a hamartoma?

(A) Acral nevus
(B) Becker nevus
(C) Dysplastic nevus
(D) Halo nevus
(E) Spitz nevus

The correct response is Option B.

A Becker nevus is a common benign cutaneous hamartoma with epidermal and/or dermal elements. These lesions can occur at birth but often develop during the second and third decades of life, and males are affected more frequently. Becker nevi are typically brown patches or plaques on the upper trunk. Hypertrichosis is commonly associated, and an underlying smooth muscle hamartoma is present. The term “nevus” is actually a misnomer because histologic examination of this lesion shows no nevus cells.

Acral nevi are typically junctional or compound and are located on the palmar or plantar surfaces.

A dysplastic nevus is referred to by several terms, including Clark’s nevus, atypical nevus, or atypical mole. This lesion is a precursor to malignant melanoma.

A halo nevus, or Sutton’s nevus, is a central melanocytic nevus surrounded by a rim or halo of hypopigmented skin. This loss of pigmentation typically corresponds with spontaneous regression of the central nevus and is thought to occur secondary to a cell-mediated and humoral immune response to nevus antigens.

A Spitz nevus is a benign proliferation of melanocytes on the face, trunk, or extremities. This lesion develops in children and is characterized by a rapid, irregular growth phase. Because it is difficult to differentiate from malignant melanoma, excision for histopathologic confirmation is recommended.

References
1. Barnhill RL. Malignant melanoma, dysplastic melanocytic nevi, and Spitz tumors: histologic classification and characteristics. Clin Plast Surg. 2000;27:331-360.
2. Casson P, Colen S. Dysplastic and congenital nevi. Clin Plast Surg. 1993;20:105-113.
3. Schaffer JV, Bolognia JL. The clinical spectrum of pigmented lesions. Clin Plast Surg. 2000;27:391-408.

A 60-year-old farmer with multiple actinic keratoses undergoes topical therapy with administration of 5% 5-fluorouracil cream for three weeks. Six months later, a 3-mm ulcer develops in the right infraorbital region and enlarges to 1 cm over three months.

Which of the following is the most likely diagnosis?

(A) Basal cell carcinoma
(B) Bowen’s disease
(C) Keratoacanthoma
(D) Seborrheic keratosis
(E) Squamous cell carcinoma

The correct response is Option E.

This 60-year-old farmer with a 1-cm ulcerated lesion in the right infraorbital region most likely has a squamous cell carcinoma. Actinic keratoses occur in older, fair-skinned persons and are thought to represent the cumulative effects of exposure to ultraviolet light. Treatment of actinic keratoses (typically with administration of 5-fluorouracil) is recommended because of the potential for malignancy; it has been estimated that 20% of patients with actinic keratoses will eventually develop cutaneous squamous cell carcinoma. However, this type of carcinoma rarely metastasizes.

Basal cell carcinomas can arise in this region and appear similar to but are less common than squamous cell carcinoma. The rapid growth (enlarging to 1 cm over a period of three months) would not be consistent with a basal cell carcinoma.

Bowen’s disease, or intraepithelial squamous cell carcinoma, occurs commonly in both sun-exposed and non-sun-exposed areas in older persons. These are typically solitary, sharply defined lesions that have red discoloration and
are covered with plaque. Potential causes of Bowen’s disease include exposure to ultraviolet light or arsenic, viral infections, chronic trauma, and heredity.

Keratoacanthomas grow rapidly over several weeks and regress spontaneously over four to six months if left untreated. Because they are have been shown to progress to invasive or metastatic carcinoma in rare instances, excision for histopathologic confirmation is recommended. They are initially firm, round, flesh-colored or reddish solitary papules, then progress to dome-shaped nodules with a smooth, shiny surface and an umbilicated center with a keratin plug. The face, neck, and dorsal aspect of the arms are affected most commonly; lesions on the trunk are rare.

Seborrheic keratoses are common lesions that occur on the trunk and upper and lower extremities in middle-aged and older persons. They are sharply circumscribed and have a waxy, greasy, or pressed-on appearance with a friable hyperkeratotic surface. Pigmentation varies from mild to deep black. This is not a premalignant condition.

References
1. Stal S, Spira M. Basal and squamous cell carcinoma of the skin. In: Aston SJ, Beasley RW, Thorne CH, eds. Grabb & Smith’s Plastic Surgery. 5th ed. Philadelphia, Pa: Lippincott-Raven; 1997:107-120.
2. Thomas JM. Premalignant and malignant epithelial tumors. In: Sams WM Jr, Lynch PJ, eds. Principles and Practice of Dermatology. New York, NY: Churchill Livingstone, Inc; 1996:225-239.
3. Zarem HA, Lowe NJ. Benign growths and generalized skin disorders. In: Aston SJ, Beasley RW, Thorne CH, eds. Grabb & Smith’s Plastic Surgery. 5th ed. Philadelphia, Pa: Lippincott-Raven; 1997:141-159.

A 59-year-old man is undergoing follow-up evaluation one year after excision of a recurrent basal cell carcinoma involving the skin of the cheek. Current examination shows a slight bulge at the site of excision that is firm to palpation and is covered by a well-healed scar.

Which of the following is the most appropriate initial management?

(A) Observation
(B) Antibiotic therapy
(C) Massage therapy
(D) Incision and drainage
(E) Incisional biopsy

The correct response is Option E.

The recurrence rate following initial treatment of a basal cell carcinoma smaller than 2 cm is 10%. This rate increases to 25% following treatment of recurrent tumors and can be as high as 82% if tumor excision is incomplete. Recurrence rate is highest for tumors of the periorbital, periauricular, and perinasal regions. Morpheaform basal cell carcinoma, which is characterized by indistinct margins, is also prone to recurrence. Any patient who has had one recurrent tumor should be considered at risk for a second recurrent tumor.

Because of the risk for recurrence, any patient who has had a basal cell carcinoma (and especially those with recurrent carcinomas) should undergo frequent follow-up examinations. A biopsy should be performed if a new abnormality is detected at the site of previous excision; therefore, this patient who has a firm bulge on the cheek at the site of a previously excised basal cell carcinoma should initially undergo incisional biopsy. Any treatment should be deferred until the diagnosis is made. In this patient, a recurrent tumor will most likely be ruled out following histologic examination of the biopsy specimen. A fluid collection may be associated with the adenoid cystic variety of basal cell carcinoma. If recurrent basal cell carcinoma is excluded, the most appropriate management would be needle aspiration of the fluid and open drainage and packing of the wound or placement of a drain. If a recurrent carcinoma is found, treatment would involve surgery, radiation therapy, or a combination of both.

Antibiotics should be administered only to patients with proven infection. Massage therapy is useful for management of contracted scar tissue but is not indicated as initial management of a patient in whom a recurrent tumor may be likely.

References
1. Dinehart SM, Jansen GT. Cancer of the skin. In: Myers EN, Suen JY, eds. Cancer of the Head and Neck. Philadelphia, Pa: WB Saunders Co; 1996:143-159.
2. Stal S, Spira M. Basal and squamous cell carcinoma of the skin. In: Aston SJ, Beasley RW, Thorne CH, eds. Grabb & Smith’s Plastic Surgery. 5th ed. Philadelphia, Pa: Lippincott-Raven; 1997:107-120.

Which of the following lesions has been shown to result from sun exposure?

(A) Dermatofibroma
(B) Ephelides
(C) Lentigines
(D) Seborrheic keratoses
(E) Xanthelasma

The correct response is Option C.

Lentigines are benign pigmented macules that result from increased activity of epidermal melanocytes; these lesions do not fade in the absence of sun exposure. The two primary types of lentigines are simple, which can occur in any area and usually develop during childhood, and solar, also known as senile, which occur in sun-exposed areas such as the face, dorsal aspect of the hands and forearms, and upper trunk.

Dermatofibromas are common benign, fibrous, papular lesions smaller than 1 cm that develop on the trunk and upper or lower extremities in early and middle adulthood. These lesions may be induced by minor trauma and are more common in women than in men. It is important to differentiate them from dermatofibrosarcoma protuberans, which is a malignant tumor. Histologic examination of a biopsy specimen of a dermatofibroma will show localized proliferations of fibrohistiocytes within the dermis.

Ephelides are common pigmented freckles that are not related to sun exposure. They contain a normal quantity of melanocytes, but the amount of melanin within the epidermal cells is increased.

Seborrheic keratoses are benign keratinocytic tumors seen in patients older than age 30 years. They exhibit a classic waxy, greasy, or pressed-on appearance and may have a generalized distribution.

Xanthelasma involves multiple, soft, yellow-orange plaques that occur around the eyes as a result of deposition of lipid-laden macrophages. Approximately 30% of patients with xanthelasma have a disorder of lipid metabolism.

References
1. Pelc NJ, Nordlund JJ. Pigmentary changes in the skin: an introduction for surgeons. Clin Plast Surg. 1993;20:53-65.
2. Schaffer JV, Bolognia JL. The clinical spectrum of pigmented lesions. Clin Plast Surg. 2000;27:391-408.

A 45-year-old man has had a painful lesion on the left ear for the past six months. The patient says that he typically sleeps on his left side. Physical examination shows a nodule on the antitragus. Histologic examination of a shave biopsy specimen shows no evidence of malignancy.

Which of the following is the most likely diagnosis?

(A) Acrochordon
(B) Chondrodermatitis nodularis helicis
(C) Dermatofibroma
(D) Sebaceous hyperplasia
(E) Xanthelasma

The correct response is Option B.

The most likely diagnosis is chondrodermatitis nodularis helicis, also known as chondrodermatitis nodularis chronica helicis, a benign lesion of the ear that usually occurs in men older than age 40 years. This is a painful erythematous nodule that typically involves the helix or antihelix and often occurs on the side that the patient prefers to sleep. Although intralesional injection of corticosteroids may be curative, shave excision or direct excision is usually required to exclude the possibility of cutaneous malignancy.

Acrochordons are simple skin tags that occur more frequently with age.

A dermatofibroma is a common benign, fibrous, papular lesion usually seen on the trunk and upper or lower extremities in early and middle adulthood. This lesion is more common in women than in men.

Patients with sebaceous hyperplasia have small, yellowish lesions that usually occur on or around the face.

Xanthelasma involves multiple soft yellow-orange plaques, typically in the preorbital area, that result from deposition of lipid-laden macrophages. Approximately 30% of affected patients have a disorder of lipid metabolism.

References
1. Graham GF. Cryosurgery. Clin Plast Surg. 1993;20:131-147.
2. Harris AO, Levy ML, Goldberg LH, et al. Nonepidermal and appendageal skin tumors. Clin Plast Surg. 1993;20:115-130.
3. Morganroth GS, Leffell DJ. Nonexcisional treatment of benign and premalignant cutaneous lesions. Clin Plast Surg. 1993;20:91-104.