Chronic lymphedema: especially in postmastectomy lymph node resection
Likely due to a combination of increased lymphatic proliferation, which increases the likelihood of malignant cells, and a decreased number of lymph nodes, which decreases the ability to remove the malignant cells.
Chemicals: Vinyl chloride and arsenic are implicated in hepatic angiosarcoma.
Clinical features
Location
More common in sun-exposed areas
Usually occur on the head, neck, and breast
May involve the internal organs (e.g., hepatic angiosarcoma)
