๐ ็ธฝ็ฎ้ ๏ฝ ๐ ่ฑๆๅๆ๏ผๆฌ็ฏ๏ผ ๏ฝ ๐ ๅฎๆด็ฟป่ญฏ ๏ฝ โญ ็ฒพ่ฏ็ญ่จ
Pseudomyogenic hemangioendothelioma
Pseudomyogenic hemangioendothelioma
Clinical features
Pseudomyogenic hemangioendothelioma is a recently delineated low-grade malignant vascular tumor previously described under the terms fibroma-like epithelioid sarcoma and epithelioid sarcoma-like hemangioendothelioma.1โ5 Lesions usually affect children and young adults and are more common in males. Tumors present as multifocal (in up to a two thirds of cases) variably painful nodules, most often located on the limbs. Lesions usually affect multiple tissue planes of the same anatomic region, such as the skin, subcutis, and skeletal muscle, and less often bone. Involvement of the oral cavity has been described and primary osseous tumors may occur.6โ8 A tumor associated with fibrous dysplasia and a further case clinically mimicking a dermatofibroma have been reported.9,10 The rate of local recurrence of up to 60% but aggressive behavior with metastasis to lymph nodes, distant organs and death is rare.1,11
Differential diagnosis The most important differential diagnosis is with epithelioid sarcoma, which usually lacks rhabdoid cells, displays atypical epithelioid cells with mitotic activity and shows positivity for EMA and CD34 (50% of cases) and loss of INI1. In cases of doubt FOSB immunohistochemistry can be useful.16