Malignant Neoplasms: Vascular Differentiation

Introduction

Angiosarcomas (AS) are rare, aggressive and malignant neoplasms. These lesions can be classified as low-grade and high-grade neoplasms. Low-grade AS include: endovascular papillary angioendothelioma (Dabska's tumor), retiform hemangioendothelioma, epithelioid hemangioendothelioma and composite hemangioendothelioma. Endovascular papillary angioendothelioma and retiform hemangioendotheliomas are probably the same entity. These lesions are locally aggressive and seldom metastasize. High-grade AS include: AS of the face and scalp of the elderly, AS associated with lymphedema, and radiation-induced AS.

History

In 1903, Mallory introduced the term hemangioendothelioma to describe a vascular tumor that infiltrated surrounding tissue, recurred locally, and may metastasize distally. In 1943, Arthur Purdy Stout used the term hemangioendothelioma to describe vascular neoplasms with malignant behavior. Angiosarcoma of the scalp and face of the elderly was first described by Caro and Stubenranch in 1945, but it was Wilson Jones in 1964 who first provided detailed information about the clinical and histopathologic aspects of this variant of cutaneous angiosarcoma. In 1948, Stewart and Treves reported six cases of angiosarcoma in postmastectomy lymphedema. In 1982, Weiss and Enzinger proposed the terms hemangioendothelioma and epithelioid angiosarcoma. In 1969, Maria Dabska reported an unusual neoplasm in six children who ranged in age from 4 months to 15 years. She denominated this neoplasm endovascular papillary angioendothelioma. The term retiform hemangioendothelioma was coined by Calonje et al. Finally, Nayler et al. introduced the term composite hemangioendothelioma in 2000.

Epidemiology

Angiosarcomas are an exceedingly rare type of vascular sarcoma. Approximately one-third of the reported cases occur in the skin. Approximately 50% of angiosarcomas occur in the head and neck. The African-American population and those individuals younger than 50 years of age are rarely affected. Of all the sarcomas affecting the head and neck, 10% are angiosarcomas.

High-grade angiosarcomas have a poor prognosis, they are highly aggressive and are often multicentric. These neoplasms have high recurrence and mortality rates. They tend to metastasize quite readily because of their intrinsic biologic properties. The 5-year survival rate is around 20%. Between 20% and 30% of AS metastasize to regional lymph nodes, which is higher than for most sarcomas.

Angiosarcomas can affect any location of the body, but they have a predilection for skin and superficial soft tissue and are usually found on the head and neck of elderly people. The peak age of incidence for AS is around the seventh decade, with a range of 18 to 91 years. The median age ranges from 60 to 71 years, and the male:female distribution is roughly equal. However, for head and neck angiosarcomas, the male:female ratio is almost 2:1, and the median age is 71 years.