Multifocal capillary hemangioma (hemangiomatosis) of the spleen.

BACKGROUND The spleen is mainly affected by benign tumors that originate from the vascular endothelium. The most common is hemangioma, which presents as a small, localized lesion. Isolated diffuse hemangiomatosis of the spleen is a rare entity in which the entire splenic parenchyma is replaced by a proliferation of neoplastic blood vessels. Here we illustrate the case of a 26-year-old man presenting with splenomegaly due to diffuse hemangiomatosis of the white pulp who underwent a splenectomy. METHODS Representative samples of the spleen were stained with hematoxylin and eosin, and immunohistochemical analysis was performed for Mib-1, CD20, CD30, CD15, CD34, CD31, CD8, factor VIII, D2-40, CD68PGM1, and LMP1. RESULTS Macroscopically, the splenic parenchyma contained multiple, red-brown nodules ranging from 0.4 to 1.5 cm. Microscopically, the nodules were roundish and confluent with an angiomatoid appearance and high positivity for CD34 and factor VIII, while they were negative for D2-40. CONCLUSIONS The differential diagnosis of splenic tumors includes lymphangioma, lymphangiomatosis, peliosis, littoral cell angioma, hemangioendothelioma, hamartoma, angiomatoid transformation of the spleen, and angiosarcoma. It is debated whether diffuse hemangiomatosis is a malformation of the postsinusoidal venous system or a slowly growing neoplasm arising from the splenic sinuses. The positivity of the cavernous vessels for CD8 seems to be in favor of the malformative nature of the tumor.