Myopericytoma of the hypothenar eminence: case report.

Myopericytomas belong to a benign group of tumors consisting of perivascular myopericytes or pericytes with a characteristic myoid differentiation pattern. The tumor is histologically and radiographically heterogenous, similar to superficial myofibromas. We report on a case of a myopericytoma arising in the hypothenar eminence of a 58-year-old man with a history of over 15 years of ulnar-sided and midcarpal wrist pain. Decision was made to excise the mass after it had increased in size by over 50 % over a 10-year period. Excision of the mass led to remarkable relief of his symptoms in the hypothenar as well as midcarpal regions. Consideration of this rare perivascular tumor should be included in patients with slow-growing benign appearing masses within the subcutaneous tissues of the hand.