Polycythemia Secondary to Renal Hemangioblastoma: A Case Report and Literature Review

Secondary polycythemia is a paraneoplastic syndrome observed in tumors with excessive erythropoietin (EPO) production. Renal cell carcinoma (RCC) and cerebellar hemangioblastoma are the 2 most well-known tumors to induce secondary polycythemia. Hemangioblastomas occurring in the kidney are rare. In this work we present a case of renal hemangioblastoma that caused erythrocytosis in a 19-year-old man. We demonstrated intratumoural EPO production by immunohistochemistry, and conducted whole-exome sequencing to evaluate possible genetic alterations that reported to induce tumor-related polycythemia. In spite of an indolent clinical behavior, renal hemangioblastoma is difficult to differentiate from RCC not only clinically, but also histopathologically. Given that RCC is the most well-known renal tumor to induce erythrocytosis, the uncommon manifestation of polycythemia in renal hemangioblastoma, as shown in our case, can cause further diagnostic challenges. Renal hemangioblastoma should be listed in the differential diagnoses of renal tumors presenting with erythrocytosis, apart from the most common RCC.

Automated summary

Secondary polycythemia is a paraneoplastic syndrome characterized by excessive erythropoietin (EPO) production in tumors. Renal cell carcinoma (RCC) and cerebellar hemangioblastoma are the most well-known tumors associated with secondary polycythemia. This case study presents a rare occurrence of renal hemangioblastoma causing erythrocytosis in a 19-year-old male. The diagnosis was established through immunohistochemistry to confirm intratumoural EPO production and whole-exome sequencing to identify potential genetic alterations.