Syndrome of neutrophil agranulocytosis, hypogammaglobulinemia, and thymoma.

The clinical, hematologic, and immunologic findings of a syndrome of agranulocytosis, hypogammaglobulinemia, and thymoma are described. Neutrophil agranulocytosis predisposing to severe infectious disease resulted from a deficiency of mature cells in bone marrow. Autologous and heterologous stem cell growth in vitro was inhibited by the patient's serum. Immunoglobulin deficiency was secondary to the absence of peripheral blood B lymphocytes, while T-cell subpopulations and cellular immunity were present. Surgical removal of a spindle cell thymoma had no effect on the agranulocytosis and B-cell deficiency. The hematologic findings did not respond to steroid therapy and cyclophosphamide. However, the agranulocytosis improved with repeated plasmapheresis and the patient achieved a clinical remission.