(250) Neurocristic Cutaneous Hamartoma with Unusual, Deep Proliferative Characteristics

Track
Case Reports
Abstract

Neurocristic cutaneous hamartoma (NCH) is a rare tumor that may consist of various cellular elements of neural crest origin, including melanocytes, neural cells, and pigmented dendritic cells. We describe a case of NCH in a 2-year-old African American male with a multinodular clinical appearance and unusual deep proliferative features without malignant transformation histologically. Physical exam revealed three clustered pruritic, painless, smooth, soft, compressible, skin-colored, nodules (surrounded by patches of alopecia) on the vertex scalp, measuring from 1.0 to 0.4 cm in size. Ultrasound revealed hypoechoic, fluid-filled nodules involving the skin and subcutis. A punch biopsy was performed demonstrating a fibrous, pigmented spindle cell proliferation involving the dermis and periadnexal structures. Scattered dendritic pigmented cells stained for S100 with variable MART-1, SOX10, and HMB45 immunoreactivity. The deep dermis demonstrated lobules of bland spindled cells in a myxoid background. A subset of cells, including deeper spindled cells, were positive for CD34 immunostain. Neurofilament highlighted a subset of cells, while EMA and GFAP were negative. Significant cytologic atypia was not appreciated. Complete excision was performed to reduce the risk of recurrence or progression. In the literature, malignant transformation occurred 1 to 67 years after initial NCH diagnosis, with most cases resulting in death shortly after diagnosis of malignant transformation. This potential for progression to malignancy makes it crucial to obtain correct initial diagnosis of NCH with complete excision and careful follow-up.

Published in: ASDP 61st Annual Meeting

Publisher: The American Society of Dermatopathology
Date of Conference: November 4-10, 2024