Splenic lymphoma: unusual case with exclusive red pulp involvement.

A case of Primary Malignant Lymphoma of the Spleen (PMLS) with exclusive red pulp involvement is described and discussed. Although the unusual topographic presentation the authors emphasize the physiologic arrangement of lymphoid cell in splenic red pulp cords that can give origin to the neoplasia. They moreover discuss problems of differential diagnosis with Malignant Histiocytosis (MH), Hairy Cell Leukemia (HCL) and Myeloid Process, both by morphology and immunohistochemistry.