1. The simultaneous occurrence of a benign thymoma and a severe anemia which failed to respond to therapy with recognized hematopoietic agents has been observed in two adult female patients.
2. Reports of seven other patients with a similar association of thymoma and refractory anemia have been found and the, salient features of these cases are summarized.
3. Possible explanations of the simultaneous occurrence of these two unusual conditions are discussed.
4. It is suggested that the thymus gland or tumors of the thymus may be etiologically responsible for certain cases of refractory anemia.