Extracutaneous manifestations of Kaposi's sarcoma: a systemic lymphoblastoma.

Kaposi's sarcoma may affect any system of the body. Serious difficulties occur only when the heart, lungs or gastrointestinal tract are affected. Usually, involvement in other viscera causes no clinical symptoms.This neoplasm is thought to be a low-grade lymphoblastoma. This idea of relationship is based on clinical and histologic association of Kaposi's sarcoma with the lymphoblastomas more commonly than would be anticipated from the rarity of the conditions under consideration. This concept is strengthened by the occasional seeming mutation of Kaposi's sarcoma into a lymphoblastoma. The associated reticuloendothelial hyperplasia in Kaposi's sarcoma is another link in the evidence of relationship.