1973 Volume 14 Issue 12 Pages 1198-1205
A 68-year-old man was admitted to the Hiraki Medical Clinic of the Okayama University in May, 1973, because of severe anemia. In 1969, he noted muscle weakness of bilateral arms and difficulty of mastication. When he had consulted his physician with signs of upper respiratory infection in 1972, a roentogenogram of his chest revealed a left hilar mass to be made a diagnosis of malignant thymoma. He developed progressively severe general fatigue and anemia since two months.
Physical examinations were unremarkable except for the presence of muscle weakness, pallor and systolic heart murmur.
Laboratory studies revealed hemoglobin 46%, hematocrit 21%, white blood cell count 10,500 per cmm with 66% neutrophils and 30% lymphocytes, platelet count 76,000 per cmm and red blood cell count 2,560,000 per cmm. Reticulocyte counts were 0%. Sternal bone marrow aspiration revealed hypoplasia of the erythroid precursore. Antinuclear and anti-erythroblast nucleus antibodies were found by indirect immunofluorescence method. Direct Coombs' test was positive though indirect was negative. The other immunological examinations examined were all negative.
Pneumomediastinography demonstrated a smoothly circumscribed mass arising from the anterior-inferior mediastinum.
In May, 1973, a thymectomy was performed and a well encapsulated tumor measuring 15×9×7 cm was removed from the anterior mediastinum. Histology of the tumor revealed a thymoma consisted with lymphoepithelial cells.
Postoperatively the patient did well in myasthenia gravis, but there was no evidence of a reticulocyte response. Direct Coombs' test became negative, but the other examinations were unchangeable.
Eighteen case reports concerning a syndrome with thymoma, pure red cell aplasia and myasthenia gravis have been reported since 1939. From these data, thymus seems to have some immunological effects on hematopoiesis and skeletal muscle organs.
