Polycythemia secondary to renal dromedary hump in a young healthy woman: a case report.

backgroundRenal dromedary hump is a benign anatomic variant with same echogenicity and blood flow as normal renal parenchyma in imaging modalities. In the present study, we report secondary erythrosytosis due to renal dromedary hump in a young healthy woman. CASE PRESENTATION: A 32-year-old, previously healthy Persian woman referred to our clinic with a 2-month history of bruises. On investigations, patient had elevated hemoglobin (19 g/dL) hematocrit (69%), red blood cell count (7.5 million per microliter) and serum erythropoietin level (708 mU/mL). The only abnormal finding in imaging modalities were a renal dromedary hump in the left kidney, mild splenomegaly, and kidney enlargement. Secondary polycythemia due to renal dromedary hump was the most likely diagnosis. The patient refuses further investigations or treatment. She occasionally comes to our clinic for phlebotomy.

conclusionDromadory hump as focal bulging of left kidney may contain a group of erythropoietin-producing cells. We think that these cells may begin to produce erythropoietin under certain circumstances. Considering the significant rise in erythropoietin level in our patient and excluding other diagnoses, we think more studies are needed to identify whether renal hump can be a source of producing erythropoietin.