Primary tumors of the spleen.

Tumors of the spleen are rare compared to the incidence of such tumors in other parenchymatous organs. Their classification has varied with both time and author. They can be divided into two main categories: nonlymphoid and lymphoid. The most common nonlymphoid tumors are the vascular tumors which include benign and malignant haemangiomas, littoral cell angiomas, lymphangiomas and haemangioendotheliomas. The remaining nonlymphoid tumors, such as fibrosarcoma, neurinoma, and lipoma are very uncommon. The lymphoid tumors include Hodgkin's and non Hodgkin's lymphoma, histiocytic lymphoma and plasmacytoma. Metastatic tumors to the spleen mainly originate from melanoma, breast and lung lesions. However, metastases to the spleen are rare compared to those of other parenchymatous organs.