From the Research
Renal cell carcinoma is the most common solid tumor associated with polycythemia, and it should be considered as a potential cause in patients with unexplained increased red blood cell count. Solid tumors that cause polycythemia include renal cell carcinoma, hepatocellular carcinoma, cerebellar hemangioblastoma, and uterine fibroids. These tumors can lead to secondary polycythemia by producing excessive erythropoietin (EPO), the hormone that stimulates red blood cell production in the bone marrow. The mechanism involves tumor cells either producing EPO directly or causing local hypoxia that triggers EPO release, as seen in a case report of a patient with metastatic renal cell carcinoma who presented with secondary polycythemia that improved with chemotherapy 1. Other less common tumors that may cause polycythemia include pheochromocytoma, adrenal adenoma, and meningioma.
When evaluating a patient with unexplained polycythemia, clinicians should consider abdominal imaging to rule out these underlying malignancies, particularly if the patient has other concerning symptoms such as flank pain, hematuria, or unexplained weight loss. Treatment focuses on addressing the underlying tumor, which often resolves the polycythemia once the source of excess EPO is removed, as demonstrated in a case report of a patient with renal hemangioblastoma that caused erythrocytosis, where the patient's polycythemia resolved after surgical removal of the tumor 2. It is essential to note that secondary polycythemia can be managed with chemotherapy and immunotherapy in renal cell carcinoma, with anti-cancer agents preventing the need for phlebotomy, as reported in a study published in the European journal of case reports in internal medicine 1.
Some key points to consider when evaluating a patient with polycythemia include:
- Renal cell carcinoma is the most common solid tumor associated with polycythemia, affecting approximately 1-5% of patients with this cancer 3
- Other less common tumors that may cause polycythemia include pheochromocytoma, adrenal adenoma, and meningioma
- Treatment focuses on addressing the underlying tumor, which often resolves the polycythemia once the source of excess EPO is removed
- Secondary polycythemia can be managed with chemotherapy and immunotherapy in renal cell carcinoma, with anti-cancer agents preventing the need for phlebotomy 1
- Abdominal imaging should be considered to rule out underlying malignancies, particularly if the patient has other concerning symptoms such as flank pain, hematuria, or unexplained weight loss.