Sclerosing perineurioma: a rare benign tumor in a pediatric patient.

A 15-year-old boy presented to outpatient dermatology clinic for evaluation of a lesion on the hand. Originally small and asymptomatic, the lesion had rapidly enlarged in the six months prior to evaluation. A shave biopsy was performed and histopathologic evaluation demonstrated a well-circumscribed nodular proliferation of dense, bland, epithelioid to spindle cells on a fibrillary background. Tumor cells were diffusely epithelial membrane antigen (EMA) positive; S100 and Melan-A were negative. These findings are consistent with a diagnosis of sclerosing perineurioma. This case illustrates the presentation of sclerosing perineurioma in a pediatric patient and we review the pertinent pathologic and immunohistochemical findings necessary for diagnosis. It is imperative to distinguish this entity from other soft tissue tumors on the hand, both benign and malignant, to avoid overly aggressive surgical intervention.