Erythrocytosis due to erythropoietin-producing uterine fibromyoma.

Erythrocytosis has been observed to occur infrequently in association with uterine fibromyomas. Study of this case revealed erythrocytosis prior to surgery and a remission was noted after myomectomy. Elevated erythropoietin activity in this patient's serum was demonstrated. The erythropoietin activity in the tumor tissue extract was 10 times higher than in the control tissue extract. We postulate that the tumor itself was responsible for the erythrocytosis observed. The mechanisms proposed to explain polycythemia in such a tumor were revised and our conclusion is that the tumor produced the erythropoietin autonomously and is not subjected to feedback control mechanism.