Epithelioid granulomatosis with initial and predominant manifestation in spleen. Morphological and immunohistochemical analysis of six cases.

In six patients with systemic symptoms, four of which had lymphoplasmacytic infiltrates in the bone marrow splenectomy was performed because of suspected malignant lymphoma, with resolution of clinical symptoms. The spleen showed epithelioid granulomas, and neither splenic tissue nor clinical follow-up revealed evidence of malignant lymphoma. Immunohistochemical analysis documented an identical phenotype in epithelioid and giant cells as well as in large numbers of CD4 + lymphocytes and S100 + interdigitating reticulum cells within the granulomas. These cases are interpreted to represent epithelioid granulomatosis with primary and/or predominant manifestation in the spleen.