Abstract

A 53-year-old female presented with a 3 x 3mm pink-white fleshy papule on the left shoulder. Sections of the biopsy showed a well-circumscribed, unencapsulated, multinodular, dermal proliferation consisting of the bland spindle to epithelioid cells and multinucleated cells within the background of the abundant myxoid stroma. No necrosis, mitosis, or cytological atypia was identified. IHC showed cells to be positive for CD34, CD68 (patchy), vimentin, and negative for CKAE1/AE3, Mart-1, HMB-45, SOX10, S100, EMA, Desmin, SMA, CD31, and GFAP. Alcian blue highlighted the myxoid stroma, and the Ki-67 proliferation index was low (<1%). Although the histopathological findings were consistent with the typical presentation of myxoid neurothekeoma, immunohistochemical examination showed a negative S100 and a positive CD68. Neurothekeoma is a rare, benign cutaneous neoplasm presenting as a slowly growing papule/ nodule mainly located on the face, shoulders, and upper extremities. It is subclassified into myxoid, cellular, or mixed, based on the quantity of myxoid matrix and immunohistochemical profile. Neurothekeoma is treated with simple excision and can recur in case of incomplete excision. No metastasis has been reported to date in the literature. We present this case to highlight this immunohistochemical variant of Myxoid Cellular Neurothekeoma.

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