A 32-year-old male was hospitalized with high fever, pancytopenia and hepatosplenomegaly. No atypical cells were found in the peripheral blood. Bone marrow aspiration resulted in dry taps. Superficial lymph node swelling was not observed. He had been treated twice for high fever, hepatosplenomegaly and leukopenia that were very similar to the present illness, 13 and 3 years before the onset and hepatosplenomegaly had been noted by the patient for 13 years. The patient died after a rapid course of 20 days. Histiocytic medullary reticulosis (HMR) was diagnosed at the autopsy, which revealed atypical histiocytic infiltration showing erythrophagocytosis in the liver, spleen, left adrenal, and mesenterial and pulmonary hilar lymph nodes. This patient had shown the same clinical signs and hepatosplenomegaly 13 years before the onset of HMR, which suggest a possible latent stage and acute exacerbation of HMR.