Sclerosing acral skin perineurioma: clinicopathologic study of ten cases (eight classical and two with xanthomatous changes)

Perineurioma is an infrequent and benign cutaneous neoplasm characterized by proliferation of perineurial cells. It is classified into two main types: intraneural and the extraneural or soft tissue perineurioma, in which the sclerosing variant is included. Sclerosing perineurioma is more frequently found on acral skin. Clinically, they are well-circumscribed,skin colored, nodular tumors. Describe and communicate clinicopathologic findings from a case series of sclerosing acral perineurioma. This is a clinical, morphological and immunohistologic case study of eight patients with the diagnosis of sclerosing perineurioma. It included five men and five women, with ages ranging between nine and 66 years. All of them had lesion on acral skin. At microscopy study, the lesions showed a proliferation of epithelioid and spindle-shaped perineurial cells, arranged in small aggregates and short fascicles between thickened collagen bundles. Immunohistochemistry studies revealed that the proliferating cells expressed EMA, Claudin-1 and Glut-1, and were negative for S-100 protein. It is important to report these infrequent skin tumors, so they can be taken into account in the differential diagnoses of acral lesions.