Epithelioid hemangioma of the penis: a clinicopathologic and immunohistochemical analysis of 19 cases, with special reference to exuberant examples often confused with epithelioid hemangioendothelioma and epithelioid angiosarcoma

Epithelioid hemangiomas of the penis are very rare. To date, less than 10 examples have been reported in the English language literature. In this report, we describe the clinical, histopathologic, and immunohistochemical findings in 19 cases retrieved from our files. The patients ranged in age from 23 to 75 years (median age, 45 years) at the time of initial surgical resection. Seventeen patients presented with a solitary mass, and two presented with two separate, but closely approximated, lesions. The process involved the glans penis (n = 3), shaft (n = 11), base of the penis (n = 2), or penis, not otherwise specified (n = 3). The lesions ranged in size from <0.5 to 2.5 cm (median size, approximately 1.2 cm) in greatest dimension. Eleven examples were specifically noted to be dorsally located, and only one was stated to be ventral. Localized pain or tenderness was the most common complaint, documented in 12 cases. The preoperative duration of the lesions ranged from 5 days to 1 year (median 4.5 months). Microscopically, all examples contained a tumefactive proliferation of epithelioid endothelial cells, often in a nodular or lobular configuration and associated with an inflammatory infiltrate containing lymphocytes and eosinophils. In 14 cases, the vascular proliferation was associated with a small arterial segment, sometimes with mural damage and frequently (n = 13) with intraluminal epithelioid endothelial cells. Based on the growth pattern of the epithelioid endothelial cells, 13 cases were considered "typical," and six were considered exuberant or "atypical." The latter examples had a prominent centrally located zone where nests or sheet-like aggregates of epithelioid endothelial cells did not form discrete vessels. Immunohistochemical data are available for 15 tumors. The epithelioid endothelial cells usually had strong reactivity for CD31, lesser reactivity for factor VIIIrAg, and minimal reactivity for CD34. In 9 of 12 cases, a small number of epithelioid endothelial cells expressed keratins. In all cases tested, at least focal muscle-specific actin-positive myopericytic cells were present bordering the endothelial cells, and this was especially notable peripherally. Initial surgical intervention consisted of either a shave biopsy (n = 1), excisional biopsy (n = 2), or local excision (n = 16). A complete follow-up history is available for 12 patients, and incomplete follow-up information is available for an additional four patients. One patient developed a new epithelioid hemangioma at a site within the penis separate from the initial lesion, but no patient is known to have experienced a true metastasis or to have died of complications of this process. Optimal management appears to be complete local excision with periodic follow-up visits to monitor for local recurrence.