Series Editor: Herbert L. Fred, MD

Prepared by Herbert L. Fred, MD, Professor, and Kevin A. Grimes, MD, Resident, Department of Internal Medicine, The University of Texas Health Science Center, Houston

A previously healthy 55-year-old man presented with a 3-week history of diffusely swollen gums (Figure) that had made eating difficult. Examination disclosed shotty generalized lymphadenopathy, a palpable spleen, and ecchymoses over both legs. His total leukocyte count was 96.2 x 10³/μL with 12% lymphocytes, 38% monocytes, and 50% blasts. Findings from a bone marrow study were diagnostic of acute myelomonocytic leukemia (FAB-M4). Chemotherapy induced a complete hematologic remission with resolution of the physical abnormalities.

Points to remember: Major infiltration of the gums by leukemic cells is common in acute myelomonocytic or monocytic leukemia and may be the presenting manifestation. This feature is less frequent in other types of acute leukemia.

Noticeable gingival hypertrophy may also result from several drugs—phenytoin, cyclosporine, nifedipine, diltiazem, verapamil, and penicillamine—and from various maladies—scurvy, sarcoidosis, Crohn’s disease, amyloidosis, lymphoma, Kaposi’s sarcoma, cytomegalovirus infection, Wegener’s granulomatosis, and hereditary gingival fibromatosis.

Diagnosis:  Acute myelomonocytic leukemia (FAB-M4).