EPO-producing gastric carcinoma in a hemodialysis patient.

A case of erythrocytosis caused by gastric cancer that produced erythropoietin is described. To the authors' knowledge, no case of erythropoietin-producing gastric cancer has been reported until now. A 73-year-old man with a 4-year history of maintenance hemodialysis for diabetic nephropathy required phlebotomy. Serum erythropoietin level was 181 mU/mL (181 IU/L). Gastroscopy results showed rough mucosa with hemorrhaging caused by gastric cancer. The patient underwent distal gastrectomy, and serum erythropoietin level decreased to 27.1 mU/mL (27.1 IU/L) by postoperative day 8. Existence of erythropoietin in the tumor tissue was confirmed immunohistochemically. The presence of severe acquired cystic disease of the kidney, renal cell carcinoma, and other malignant tumors should be investigated in hemodialysis patients displaying erythrocytosis.