Angiosarcomas

Angiosarcoma is a rare malignant tumor arising from the endothelial cells that line blood and lymphatic vessels. It can involve any tissue but most commonly presents in the skin, especially the scalp and face of elderly individuals, with possible involvement of soft tissue, breast, liver, spleen, and heart. Angiosarcomas are aggressive tumors with a high risk of local recurrence and early distant metastasis.

Risk factors and etiologies include chronic lymphedema (Stewart-Treves syndrome after mastectomy-related lymphedema), prior radiation exposure (notably breast irradiation), and environmental carcinogens such as vinyl chloride, arsenic, and thorium. The disease can be primary or radiation-associated, and certain sites such as the scalp have a particularly poor prognosis.

Pathology and diagnosis are based on histology and immunohistochemistry. Microscopically, angiosarcoma shows irregular, anastomosing vascular channels lined by atypical endothelial cells, with papillary or solid areas and frequent mitoses. Immunohistochemistry is typically positive for endothelial markers such as CD31, ERG, and factor VIII-related antigen; CD34 can be variably positive, and cytokeratin is usually negative. In radiation-associated cutaneous angiosarcoma, MYC amplification may be observed.

Imaging with MRI or CT assesses extent and staging, and lesions are often hypervascular. Treatment centers on complete surgical excision with negative margins when feasible; breast angiosarcoma post-radiation may require mastectomy. Adjuvant radiotherapy or chemotherapy is considered in high-risk or unresectable cases. Agents such as doxorubicin or paclitaxel are commonly used in advanced disease. Overall prognosis is poor, with outcomes highly dependent on tumor size, depth, grade, and presence of metastasis; 5-year survival varies and is generally unfavorable, particularly for scalp and facial lesions.