[Invasive thymoma in patient with pernicious anemia and pericardial effusion]

A 69-year-old woman was admitted to the hospital because of coughing, dyspnea, generalized fatigue, and pretibial edema. A chest X-ray film revealed cardiac enlargement, a left hilar mass, and a small nodule in the right middle lung field. Echocardiography showed a massive pericardial effusion. A chest CT scan showed pericardial effusion, an anterior mediastinal mass, and a small nodule in the right upper lobe. Examination of a percutaneous biopsy specimen showed round and spindle-shaped tumor cells and lymphocyte infiltration, which was consistent with mixed-cell-type thymoma. Hematological examination showed macrocytic anemia, and the concentration of vitamin B12 was 65 pg/ml (249-938 pg/ml). A test for anti-parietal cell antibodies was positive. Our diagnosis was pernicious anemia and stage IVb invasive thymoma (by Masaoka's classification). Because of the intrapulmonary metastasis and pericardial effusion, the patient underwent chemotherapy. The tumor shrank, so a thoracotomy was done. However, the tumor was found to have invaded the heart and large vessels, and it could not be removed. After surgery the thorax was irradiated. Invasive thymoma complicated by pernicious anemia is rare.