Benign thymoma and agenesis of erythrocytes.

• At least 12 instances of benign thymic tumor associated with agenesis of erythrocytes have been noted since 1928. Six of these patients have had thymectomy, resulting in apparent cures for two, improvement for two others, and failure in the last two. At Mayo Clinic two additional patients showing this particular syndrome received thymectomy with no evident benefit after surgery. There still exists, however, a definite relation between the suppression of erythrogenesis in the presence of benign thymoma, although the exact mechanism causing the anemia is unknown. With the occasional exception of the use of thymectomy, splenectomy, transfusions, and the administration of corticotropin and cortisone, treatment has been futile.