A 79-year-old man was referred to our clinic complaining of multiple dark-brown painful nodules on the right waist and hip. Four months prior to visiting our clinic, he experienced a severe trauma on this site due to falling after losing consciousness. A biopsy specimen revealed a diffuse proliferation of atypical epithelioid cells with a slit-like appearance and extravasation of red blood cells. On immunohistology, the atypical tumor cells were strongly positive for CD31 and vimentin as well as AE1/AE3 and CAM5.2, leading to a diagnosis of epithelioid angiosarcoma. Investigation by positron emission tomography-computed tomography revealed osteolytic metastatic lesions in the pubic and ischial bones. Palliative radio-chemotherapy was performed, but he passed away 11 months after the first visit. Epithelioid angiosarcoma is a rare tumor, and in this case we needed to differentiate it from the metastatic lesions of a primary malignant epithelial tumor.
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