[Polycythemia vera and hemoregulator hormones. Considerations on an unusual clinical case].

The case is reported of a patient with polycythemia vera, who developed an anterior panhypopituitarism, due to an adenoma, some years later. The endocrine deficiency caused the return of the hemoglobin count and global red cell volume to the normal range. The finding suggests that in polycythemia vera the neoplastic growth is still partially responsive to normal hemoregulator factors.