Case 005: 38 Year Old African-American Female with a Lesion
on the Scalp

Contributed by Andre Thompson, M.D. and Kaori Saito, M.D., Supervised by Alina Jukkola, MD

Clinical History

A 38 year old African-American female presents with a 3 year history of a lesion to the scalp. There is occasionally associated pain and drainage from the lesion. Physical exam reveals 0.3cm raised, pedunculated, flesh- colored, non-tender lesion to the left temporal scalp. No ulcerations or drainage are noted. Excisional biopsy is performed.

Gross Findings

A 1.4 X 0.5 X 0.9 cm skin ellipse with a 0.4 X 0.4 X 0.4 cm, gray-brown, raised nodule on the skin surface.

Microscopic Findings

(Click a photo to view a larger image.)

Image (1) H&E, 2x Image (2) H&E, 10x Image (3) H&E. 20x Image (4) S-100, 2x Image (5) S-100, 4x Image (6) S-100, 20x

Diagnosis

Nerve Sheath Myxoma - (also known as neurothekeoma, myxoid variant) is a benign tumor of presumed peripheral nerve histogenesis. Most frequently, these tumors are found on the face or upper extremities as asymptomatic, dome-shaped nodules that measure 0.5 to 3 cm; they are NOT associated with neurofibromatosis. Females are more commonly affected than males. Surgical excision is usually curative.

Histologically, nerve sheath myxoma is a multilobulated tumor in the reticular dermis with frequent extension into the subcutis. The lobules are composed of spindle-shaped, stellate and sometimes epithelioid cells arranged in a swirling, lamellar and often concentric pattern, embedded in a variably-abundant myxoid stroma. The tumor cells may show hyperchromatism and sometimes atypia; they stain positive for vimentin and S-100 protein and, sometimes, EMA.