Familial hemophagocytic reticulosis. Clinicopathologic findings and cytochemical, immunohistochemical and electron microscopic studies.

Clinicopathologic findings of a case of familial hemophagocytic reticulosis (FHR), for which splenectomy, and biopsy of the liver and mesenteric lymph nodes were performed, is reported. Histologically, the proliferated cells consisted of not only histiocytes showing severe erythrophagocytosis, but also lymphoid cells of various sizes. The lymphoid cells had atypical features including mitotic figures and convoluted nuclei, and were suspected to be T cells as a result of immunohistochemical studies. We therefore consider that FHR is a special type of lymphoproliferative disease accompanied by severe proliferation of erythrophagocytic histiocytes rather than being a true histiocytic disease. Cytochemical and electron microscopic findings of the involved spleen are also presented.