Pure red cell aplasia and myasthenia gravis with thymoma: A case report and review of the literature

A case of pure red cell aplasia (PRCA), myasthenia gravis (MG) and thymoma is reported. A 70-year-old woman presented with severe anemia. She had been diagnosed as having MG 8 years earlier and her symptoms were adequately co ntrolled with ambenonium chloride. When she visited our hospital, her hemat ocrit was 13.7% with a hemoglobin concentration of 4.7 g/dl and her reticul ocyte counts were persistently abnormal at 0.1%, Although both direct and i ndirect Coombs' tests were positive, there was no evidence of hemolysis, Ro utine screening tests for other etiologies of anemia were negative. Serolog ical tests for anti-DNA and anti-acetylcholine receptor antibodies gave pos itive results. A bone marrow examination revealed severe erythroid hypoplas ia. PRCA was diagnosed and the patient was treated with periodic transfusio ns. A lateral view chest roentgenogram and a computed tomography scan of th e thorax showed the presence of an anterior mediastinal mass which was susp ected to be thymoma, The patient underwent thymothymectomy and the tumor wa s diagnosed as a thymoma, Although the patient received no treatment for MG and PRCA after surgery, her hematological test results rapidly improved an d she was discharged from the hospital on the 29th postoperative day. At th at time, her hematocrit was 33.2%, her hemoglobin concentration was 10.0 g/ dl, her peripheral reticulocyte level was 1.8% and her left partial ptosis had improved. She is doing well, 9 months after surgery. For a patient to r emain in remission without treatment for PRCA and MG after thymothymectomy is extremely rare.