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What is Lymphangiosarcoma and explain in detail?
Lymphangiosarcoma is a rare cancer which occurs in long-standing cases of primary or secondary lymphedema. It involves either the upper or lower lymphedematous extremities but is most common in upper extremities. Although its name implies lymphatic origin, it is believed to arise from endothelial cells and may be more accurately referred to as  angiosarcoma.

Signs and symptoms
Lymphangiosarcoma may present as a purple discoloration or a tender skin nodule in the extremity, typically on the anterior surface. It progresses to an ulcer with crusting to an extensive necrotic focus involving the skin and subcutaneous tissue. It metastasizes quickly.

Causes
It was previously a relatively common complication of the massive lymphedema of the arm which followed removal of axillary (arm pit) lymph nodes and lymphatic channels as part of the classical Halstedian radical mastectomy, as a treatment for breast cancer