In-Service Exam
Skin Lesions - 2001

A 56-year-old man has a 30-degree flexion contracture of the proximal interphalangeal (PIP) joint of the right ring finger. He has had thickening in the palm at the base of the finger for the past five years. Which of the following structures are most likely involved in the PIP joint contracture?

(A) Central and spiral cords
(B) Lateral cord and knuckle pad
(C) Natatory and retrovascular cords
(D) Retrovascular and lateral cords
(E) Spiral cord and Cleland's ligament

The correct response is Option A.

The central, lateral, and spiral cords each contribute to recurrent contracture of the PIP joint; the little finger is affected most frequently. The central cord develops from fascia between the neurovascular bundles and is continuous proximally with the pretendinous cord. It attaches distally to the tendon sheath over the middle phalanx. The lateral cord is adherent to the skin, while the spiral cord can occur as a continuation of the pretendinous cord or can arise at the musculotendinous junction of the intrinsic muscle. This cord straightens and courses less obliquely over time.

The natatory cord passes across the palm at the level of the web spaces and attaches to each individual flexor tendon sheath. Contracture of this cord can contribute to contracture of the PIP joint. Cleland's ligaments are fascial structures located dorsal to the neurovascular bundle that help to hold the skin in position during flexion and extension of the finger. These structures are only an occasional cause of PIP joint contracture. The retrovascular cord most frequently causes contractures of the distal interphalangeal joint. This longitudinally oriented fascial cord lies dorsal to the neurovascular bundle and palmar to Cleland's ligament.

Knuckle pads are a manifestation of joint contracture and not a cause themselves.

References
1. McGrouther DA. Dupuytren's contracture. In: Green DP, Hotchkiss RN, Pederson WC, eds. Operative Hand Surgery. 4th ed. New York, NY: Churchill Livingstone, Inc; 1999;1:563-591.
2. Starkweather KD, Lattuga S, Hurst LC, et al. Collagenase in the treatment of Dupuytren's disease: an in vitro study. J Hand Surg. 1996;21A:490-495.
3. Strickland JW, Leibovic SJ. Anatomy and pathogenesis of the digital cords and nodules. Hand Clin. 1991;7:645-657.
4. Watson HK, Paul H Jr. Pathologic anatomy. Hand Clin. 1991;7:661-668.

A 73-year-old farmer with severely sun-damaged skin has 15 scaly lesions smaller than 1 cm on the face. He reports that the lesions have progressively increased in size and number over the past six months. Which of the following is the most appropriate management?

(A) Phenol peeling
(B) Cryosurgery
(C) Topical 5-fluorouracil therapy
(D) Topical tretinoin therapy
(E) Surgical excision

The correct response is Option C.

This patient has findings consistent with multiple actinic keratoses, or rough, scaly, discrete lesions of the epidermis that are premalignant precursors of squamous cell carcinoma. If the lesions are few and/or isolated, appropriate management can consist of cryosurgery, curettage, or surgical excision. However, these therapies are impractical in patients who have numerous, diffuse nevi on the face or upper extremities. Therefore, in patients such as this one, topical treatment with 5-fluorouracil for three weeks will effectively remove the keratoses. Any remaining lesions should then be excised surgically due to the patient's risk for development of invasive carcinoma.

Phenol peeling can also be used to remove keratoses but is an invasive procedure with a longer and more difficult recovery phase. Tretinoin is substantially less effective than 5-fluorouracil and would exert only minimal effects in patients with diffuse keratoses.

References
1. Morganroth GS, Leffell DJ. Nonexcisional treatment of benign and premalignant cutaneous lesions. Clin Plast Surg. 1993;20:91-104.
2. Netscher DT, Anous M, Spira M. Premalignant skin tumors, basal cell carcinoma, and squamous cell carcinoma. In: Cohen M, ed. Mastery of Plastic and Reconstructive Surgery. Boston, Mass: Little, Brown & Co; 1994;1:309-332.

Which of the following lesions is associated with trigeminal nerve distribution?

(A) Blue nevus
(B) Ephelis
(C) Nevus of Ito
(D) Nevus sebaceus of Jadassohn
(E) Nevus of Ota

PHOTO

The correct response is Option E.

The above photograph depicts a nevus of Ota, a bluish gray facial lesion that occurs along the distribution of the ophthalmic and maxillary branches of the trigeminal nerve (V1 and V2) and predominantly involves the periorbital region. The cornea, nasal mucosa, and oral pharynx are rarely involved. Approximately 60% of these lesions are present at birth or develop by age 10 years, 80% are seen in female children, and 5% occur bilaterally. Because malignant transformation is rare, treatment is only indicated for cosmetic reasons.

A blue nevus is a small, well-defined intradermal nevus that rarely displays malignant transformation. Ephelis is a pigmented freckle that contains a normal quantity of melanocytes and an abnormally large quantity of melanin granules. There is no potential for malignancy. The nevus of Ito is similar to the nevus of Ota but instead follows the distribution of the lateral brachial cutaneous and supraclavicular nerves. The nevus sebaceus of Jadassohn is a yellowish orange, slightly elevated plaque seen at or soon after birth. It is a benign epidermal tumor that occurs most frequently on the scalp and face. Approximately 15% of these lesions develop into basal cell carcinoma.

References
1. Chang C, Nelson J, Achauer BM. Q-switched ruby laser treatment of oculodermal melanosis (nevus of ota). Plast Reconstr Surg. 1996;98:784.
2. Grossman MC, Kauvar AN, Geronemus RG. Cutaneous laser surgery. In: Aston SJ, Beasley RW, Thorne CH, eds. Grabb & Smith's Plastic Surgery. 5th ed. Philadelphia, Pa: Lippincott-Raven; 1997:205-219.
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.

Sebaceous carcinoma most frequently affects which of the following anatomic sites?

(A) Eyelid
(B) Finger
(C) Nose
(D) Tongue
(E) Trunk

The correct response is Option A.

Sebaceous carcinoma arises from the adnexal epithelium of the sebaceous glands. It can be divided into two subtypes; the ocular subtype, which is most common, typically arises from the meibomian gland of the eyelid. This is a more aggressive carcinoma, frequently resulting in metastasis. In contrast, extraocular lesions are common to hair-bearing areas, and metastases are infrequent.

References
1. Nelson BR, Hamlet KR, Gillard M, et al. Sebaceous carcinoma. J Am Acad Dermatol. 1995;33:1-15.
2. Pickford MA, Hogg FJ, Fallowfield ME, et al. Sebaceous carcinoma of the periorbital and extraorbital regions. Br J Plast Surg. 1995;48:93-96.

A patient who wishes to undergo cosmetic surgery for correction of skin hyperextensibility has an inherited disorder of collagen polymerization that results in laxity of the joints and poor wound healing. These findings are most consistent with

(A) cutis laxa
(B) Ehlers-Danlos syndrome
(C) progeria
(D) pseudoxanthoma elasticum
(E) Werner's syndrome

The correct response is Option B.

This patient has Ehlers-Danlos syndrome, or cutis hyperelastica, an inherited disorder of abnormal molecular collagen cross-linking characterized by hyperextensibility of the skin and laxity of the joints. Cosmetic surgery is contraindicated in patients with Ehlers-Danlos syndrome because wound healing is poor.

Patients with cutis laxa have coarsely textured, drooping skin resulting from a nonfunctioning elastase inhibitor or premature degeneration of elastin fibers. Because this condition is not associated with wound healing problems, rhytidectomy may be performed.

Progeria is an autosomal recessive disorder characterized by skin laxity, loss of subcutaneous fat, and findings of generalized atherosclerosis similar to premature aging. Aesthetic surgery is contraindicated because wound healing is poor; in addition, the lifespan of patients with progeria is shortened.

The mechanisms of action of pseudoxanthoma elasticum, an inherited disorder of premature skin laxity, include increased degradation of collagen and deposition of calcium within the elastic fibers. Rhytidectomy should be considered because healing is normal.

Werner's syndrome is a rare autosomal recessive disorder of unknown etiology. Associated features include sclerodermic skin changes and accelerated atherosclerosis, which can limit or prolong the wound-healing process.

References
1. Rees TD, Aston SJ, Thorne CH. Blepharoplasty and facialplasty. In: McCarthy JG, ed. Plastic Surgery. Philadelphia, Pa: WB Saunders Co; 1990;3:2320-2414.
2. Thorne CH, Aston SJ. Aesthetic surgery of the aging face. In: Aston SJ, Beasley RW, Thorne CH, eds. Grabb & Smith's Plastic Surgery. 5th ed. Philadelphia, Pa: Lippincott-Raven; 1997:633-649.

Patients with erythroplasia of Queyrat have squamous cell carcinoma affecting which of the following sites?

(A) Arm
(B) Ear
(C) Nose
(D) Penis
(E) Scalp

The correct response is Option D.

Erythroplasia of Queyrat is an irregular, erythematous patch of full-blown squamous cell carcinoma or carcinoma in situ that affects the penis. It is a feature of the condition known as Bowen's disease, which is characterized by widespread erythematous, brown, scaly patches. These lesions are composed of squamous cells that can completely replace normal dermis at the affected sites. Because approximately 15% of Bowen's disease lesions progress to become invasive squamous cell carcinoma, surgical excision of an erythroplasia of Queyrat is recommended.

References
1. Gerber GS. Carcinoma in situ of the penis. J Urol. 1994;151:829-833.
2. Wieland U, Jurk S, Weisenborn S, et al. Erythroplasia of Queyrat: coinfection with cutaneous carcinogenic human papillomavirus type 8 and genital papillomaviruses in a carcinoma in situ. J Invest Dermatol. 2000;115:396-401.

A 59-year-old man has a 1.5-cm lesion over the fourth extensor compartment. A morpheaform basal cell carcinoma was excised at the site of the lesion seven years ago. There is no extensor adherence or adenopathy. Which of the following is the most appropriate management of this lesion?

(A) Observation
(B) Marginal excision
(C) Mohs' micrographic resection
(D) Wide local excision
(E) Radical resection

The correct response is Option C.

This patient has a recurrence of basal cell carcinoma, a common, slow growing, nonmelanotic skin tumor that often goes unnoticed and undiagnosed. Basal cell carcinoma is six to 18 times more common than squamous cell carcinoma; sun exposure is directly associated with the development of this type of tumor. Approximately 3% of all basal cell carcinomas are found on the upper extremities. There can be as many as 26 different histologic subtypes of basal cell carcinoma, including nodular, superficial, ulcerative, micronodular, infiltrative, sclerosing, morpheic, and mixed types. The infiltrative, ulcerative, sclerosing, and morpheaform types are the most aggressive.

Several treatment options for basal cell carcinoma are associated with similar cure rates. Lesions smaller than 6 mm can be managed with curettage and electrodesiccation; radiation therapy, cryotherapy, and topical application of 5-fluorouracil are also effective. For most basal cell carcinomas (excluding sclerosing and morpheaform variants), there is a 95% cure rate when the tumor is resected with a margin of 4 mm or smaller. In contrast, aggressive lesions and recurrent tumors are best treated with wide resection with margins greater than 5 mm or controlled resection using Mohs' micrographic technique. However, Mohs' surgery will render more exact margins and is thus preferred over wide resection alone, even if the wide margins are examined by frozen section. Following excision, the wound should be covered with a skin graft, which will prevent dessication of the underlying structures and allow for histologic examination of the lesion without further risk for local tumor spread.

Radical resection is not indicated for locally recurrent morpheaform basal cell carcinoma.

References
1. Fink JA, Akelman E. Nonmelanotic malignant skin tumors of the hand. Hand Clin. 1995;11:255-264.
2. Olbricht SM. Treatment of malignant cutaneous tumors. Clin Plast Surg. 1993;20:167-180.