Angiosarcoma is a malignant tumor arising from the endothelial cells of blood vessels. According to the packet definition, it most frequently occurs in the skin and breast. Site-based subtypes are listed in the packet, such as skin, breast, liver and bone angiosarcoma. The structured prevalence category is very rare, affecting fewer than 1 per million.

Symptom and phenotype data are not certified in this packet. The definition describes the microscopic appearance: frequently open vascular anastomosing and branching channels lined by spindle or epithelioid malignant cells that often display hyperchromatic nuclei. Presentation depends on the site involved, and the packet does not list specific clinical features.

The certified gene list and inheritance fields are empty in this packet, so no genetic basis or inheritance pattern is specified. The packet definition states that patients with long-standing lymphedema are at increased risk of developing angiosarcoma. No further cause or mechanism is certified.

Diagnostic methods are not certified in this packet. The definition describes the microscopic features of the tumor, which is not presented here as a diagnostic criterion.

No approved treatment records are present in this packet, and treatment coverage is not otherwise certified. Treatment planning for malignant tumors generally depends on disease stage, tumor characteristics and overall health, and management often involves a multidisciplinary oncology team that may use surgery, local therapies, systemic approaches and supportive care. Goals may be curative or focused on symptom control depending on the situation. Orphan drug designation records exist for two products with an angiosarcoma indication; designation is not approval, and these products are described only as under development.

Prognosis is not certified in this packet, and no survival figures are supplied. Outcomes for malignant tumors depend on stage, tumor characteristics and response to treatment.

Numerous certified active trial records are present. Examples include intratumoral vusolimogene oderparepvec in combination with pembrolizumab for angiosarcoma (NCT06898970, Phase 2, recruiting), a pilot study of ivonescimab in advanced or metastatic cutaneous angiosarcoma (NCT07655570, Phase 2, M.D. Anderson Cancer Center, recruiting), pembrolizumab plus lenvatinib in unresectable cutaneous angiosarcoma (NCT06673628, Phase 2, National Cancer Center, Japan, recruiting), and broader sarcoma and rare tumor studies such as NCT04339738 sponsored by the National Cancer Institute. Trial titles do not establish what an intervention does or whether it is effective. Active clinical trials for this condition are listed on ClinicalTrials.gov.