Abstract

We present an unusual case in a 16-year-old female who presented for evaluation of an alopecic patch on scalp which had been present for 3 years with recently noted tenderness and swelling. Physical exam revealed a tender, firm, 1 cm subcutaneous nodule on vertex scalp with sparse overlying hair. Histologic examination revealed areas of basophilic, epithelioid nodules and spindled cells with foci of melanin pigment. The tumor exhibited expression of CD34, variable S100 protein, and focal expression of SOX-10. The cells were negative for SMA, EMA, ERG, HMB, and MelA. Fluorescence in situ hybridization for PDGFB amplification was negative, excluding DFSP/Bednar Tumor. Next generation sequencing revealed a TPR-NTRK1 fusion. A subsequent excision was performed with extension of the lesion to periosteum. As the majority of NTRK rearranged tumors in children tend to be indolent with potential for local recurrence, clinical surveillance was recommended. The patient is currently being followed with no evidence of recurrence.

Financial Disclosure:
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