2024 Volume 39 Issue 3 Pages 247-252
An 85－year－old male patient was referred to our department with complaints of pain and bleeding from an erythematous nodule on his right cheek. A skin biopsy revealed that it was malignant ; however, the diagnosis remained inconclusive. During follow－up, the nodule rapidly increased in size and began hemorrhaging, and was surgically removed. Histopathological examination of the completely resected tumor showed partial epidermal defects and diffuse proliferation of eosinophilic neoplasms within the dermis and subcutaneous tissue, accompanied by hemorrhage and necrosis. Architecturally, the tumor cells were predominantly arranged in sheets. Immunohistochemical staining demonstrated CD31 (+), Factor XⅢ (+), vimentin (+), and CK AE1/AE3 (+, focal), leading to a diagnosis of epithelioid angiosarcoma. Epithelioid angiosarcoma is a morphological variant of angiosarcoma but carries a worse prognosis. Cutaneous primary epithelioid angiosarcoma is particularly rare and challenging to diagnose, underscoring the importance of histopathological examination and immunohistochemical staining in confirming the diagnosis.[Skin Cancer (Japan) 2024 ; 39 : 247－252]
