Erythropoietin synthesis by tumour tissues in a patient with uterine myoma and erythrocytosis.

We report a patient with uterine myoma (leiomyoma) and erythrocytosis in whom erythropoietin (Epo) production in the leiomyoma tissue was identified by reverse transcription polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). A 48-year-old Japanese woman with uterine myoma showed marked erythrocytosis (haemoglobin: 20.2 g/dl, haematocrit: 61.1%, red blood cells: 6.51 x 10(12)/1). After hysterectomy, erythrocytosis rapidly disappeared. In the leiomyoma tissue collected from the patient, Epo mRNA expression was confirmed using RT-PCR. Furthermore, ELISA showed that the Epo protein level was significantly increased compared with those in control tissues. It is suggested that the pathogenesis of erythrocytosis in patients with uterine myoma involves ectopic Epo production by leiomyoma tissues.