[Myopericytoma-type perivascular myoma located in the soft tissue of the foot: a case report and review of the literature].

We describe a rare case of myopericytoma-type perivascular myoma (MTPM) which arose in acral location and the literature on this field is briefly reviewed. The patient, a 68-year-old man, presented with an enlarging painful nodule, 1.4 cm across, located in the subcutaneous tissue of the right foot. The patient is alive and well 17 months after surgical excision of the nodule. Microscopically, the lesion was well-circumscribed and characterized by a biphasic pattern with a concentric perivascular spindle and ovoid cell proliferation and an extensive hemangiopericytomatous growth component. Immunohistochemically, the neoplastic cells were positive for vimentin, smooth muscle actin, desmin and calponin, negative for S-100 protein, CD34, CD31 and cytokeratins (AE1/AE3, Cam 5.2). Electron microscopy showed electrondense cell bodies suggestive for myopericytic differentiation. The clinico-pathological features of the present case are similar to those previously reported in the literature and we also discuss herein the main histological criteria for the differential diagnosis with other spindle cell and vascular lesions of soft tissues.