Abstract
Thymomas are associated with a variety of immunological disorders. Recently we have experienced a case of a thymoma with pure red-cell aplasia associated with a high antiacetylcholine receptor antibody (anti-AChR antibody) level.
A 61-year-old woman presented to our hospital because of an abnormal chest shadow detected on a medical check-up. Contrast-enhanced chest CT scan showed an about 6-cm well-circumscribed tumor with homogeneous enhancement effect in the anterior mediastinum. Thymoma was suspected. In addition normocystic normochromic anemia associated with reticulocytopenia was confirmed. A bone marrow examination revealed a diagnosis of pure red-cell aplasia. Although the serum level of anti-AChR antibody was high, clinical symptoms of myasthenia gravis were absent. Extended thymectomy for the thymoma was performed. The patient's postoperative course was uneventful and she was discharged from the hospital on the 10th postoperative day. The pathological diagnosis was thymoma (type AB according to the WHO classification and in the stage II according to the Masaoka's classification). About one month later we confirmed that her anemia began to progress again, so that immunosuppressive regimen with cyclosporine was started. Her anemia showed a tendency to improve on and after one week after the regimen. The patient is kept to be independent from blood transfusion and no symptoms suggestive of myasthenia gravis have appeared up to now.
