Pseudomyogenic Hemangioendothelioma (Epithelioid Sarcoma-like Haemangioendothelioma) - Case Report of a Rare Entity

Abstract

Pseudomyogenic Hemangioendothelioma (Epithelioid Sarcoma-like Haemangioendothelioma) is a rare soft tissue tumor of endothelial origin. It is a distinctive neoplasm having indolent behaviour. A 27-year-old male presented with history of multiple small ulcers over right shoulder region since 2 months. On examination, diffuse indurated plaques were seen over right shoulder with multiple ulcers. A Provisional diagnosis of non-healing ulcer over right shoulder was offered. Pus culture was positive for coagulase negative Staphyloccus species. The lesion was excised and sent for histopathology.Microscopy showed ulcerated epidermis. Subepithelium showed tumor tissue composed of cells arranged in fascicles, sheets and irregular nodules. Individual tumor cells were oval to spindle shaped cells having brightly eosinophilic cytoplasm and vesicular nucleus with noticeable nucleoli. At places endothelial cell proliferation and neovascularization was seen. Possibility of epithelioid sarcoma, epithelioid hemangioendothelioma and malignant melanoma was considered. Immunohistochemistry was performed. Neoplastic cells were positive for vimentin, CD31, CK19 and negative for CD34, HMB45 and EMA. A final diagnosis of Epithelioid sarcoma-like Hemangioendothelioma (Pseudomyogenic Hemangioendothelioma) was offered.  It is an unusual pathological entity with a unique clinical presentation. Histopathology is challenging. Immunohistochemistry is not only confirmatory, but also mandatory to solve the diagnostic dilemma.