Abstract

Pseudomyogenic hemangioendothelioma (PMH), also known as epithelioid sarcoma-like hemangioendothelioma, is a rare epithelioid vascular neoplasm predominantly affecting young adult males with average age 30 years. This tumor is rare; therefore, detailed information regarding this tumor is still lacking. Here we report a case of a man in his 20s presenting with left foot pain for about one year. Imaging showed a 2-cm ovoid, cortically based lesion with lytic defect of the cortex at the fifth metatarsal proximal shaft. Histologically, the lesion presented as an infiltrating proliferation of distinctly myoid-appearing spindled cells with eosinophilic cytoplasm and mildly atypical vesicular nuclei. Scant mitoses were identified with no areas of necrosis. Tumor cells exhibited strong, diffuse cytokeratin expression as well as CD31 and ERG. CD34 was positive in few tumor cells, and INI1 retained nuclear expression. No reactivity for S100, Desmin, SMA, EMA, and CD1a was present. Over half of patients with PMH develop multifocal lesions, often involving several tissue planes; however distant metastasis is very infrequent. This patient underwent curettage and internal fixation of the left 5th metatarsal and had no evidence of recurrence or distant metastasis after 7 years of follow-up. Our case contributes to the growing knowledge of PMH and sheds light on the prognosis of these lesions.

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