Precursor B-cell acute lymphoblastic leukemia after thymoma and myasthenia gravis: report of a case and review of the literature.

The association of thymoma, myasthenia gravis (MG) and pure red cell aplasia (PRCA) is well recognized. The association of T-cell lymphoblastic lymphoma and thymoma/MG/PRCA is less distinctive but reported occasionally. We present a 35-year-old female patient who was diagnosed with thymoma and myasthenia gravis. She underwent a thymectomy shortly after the diagnosis. One year later she developed precursor B-cell acute lymphoblastic leukemia (ALL). Complete remission was achieved after induction chemotherapy but the disease relapsed and she expired two years after the diagnosis of ALL despite allogeneic stem cell transplantation. This association has never before been reported and the pathogenesis needs to be clarified. Aberrant thymus function in myasthenia gravis, immunosuppressive therapy and thymectomy are considered to account for the leukemia development in this patient.