Background: Perineuriomas are rare, benign, slow growing and painless tumours derived from perineurial cells. They usually present as a single asymptomatic nodule and are often found to develop in the digits and palms of young adults, particularly in males. To date, fewer than 50 cases have been reported and when occurring in the hand, have been confined to the palmar surface.
Methods: A retrospective case report of a single female patient who presented with a left ring finger dorsal middle phalanx subcutaneous lump.
Results: A 55 year old female was seen at The Austin Hospital for management of a finger lump that was asymptomatic and had been present for over 2 decades. The lump was mobile, well circumscribed and rubbery in texture. Ultrasonography showed an oval well defined hypoechoic nodule that appeared consistent with a giant cell tumour. Excision revealed a smooth, white, unencapsulated and non-lobulated lump that was thought to be a schwannoma. Histological analysis identified an unencapsulated nodule comprising small epithelioid to spindled cells within sclerosed stroma. The cells whorl around small, round blood vessels. Immunoreactivity of the lesional cells was positive for epithelial membrane antigen and negative for CD34, S100. These findings are consistent with a perineurioma of the sclerosing subtype.
Conclusion: Sclerosing perineurioma is a rare benign tumour of the hand. We believe that this is the first case of a dorsal digital sclerosing perineurioma.