We report a young woman with pancytopenia and huge splenomegaly who was also found to have peripheral T-cell lymphoma with massive infiltration of T-cell evident in the liver and spleen. A liver biopsy showed predominant sinusoidal infiltration of pan-T cell antibody-stained T-lymphoid cells. Histologic examination of the spleen revealed numerous tumor cells predominantly infiltrated in the cords and sinuses of the red pulp, which were identical to those described in the liver. Several clusters of small round abnormal cells were observed in marrow cytology. Although the patient felt well during 18 months after the splenectomy was done, the patient eventually manifested a huge hepatomegaly, showed increasing white blood cell count to 42 x 10(9)/l, and numerous prolymphocytes (66.9%) in the bone marrow. This change represented a prolymphocytic transformation of the patient's original hepatosplenic T-cell lymphoma.