Which statement describes the paraneoplastic phenomenon Stauffer syndrome in renal cell carcinoma?

• A. Erythrocytosis due to EPO production
• B. Hypertension
• C. Stauffer syndrome (non-metastatic hepatic dysfunction)
• D. Weight gain

Answer: (C)

Stauffer syndrome is a paraneoplastic phenomenon in renal cell carcinoma where the liver becomes dysfunctional despite no liver metastases. The hallmark is abnormal liver function tests, often with a cholestatic pattern (elevated alkaline phosphatase and bilirubin, sometimes mildly raised transaminases), and the liver itself looks non-diseased on imaging. This hepatic dysfunction typically improves or resolves after the kidney tumor is removed, which is a clue that the liver abnormalities are driven by the tumor rather than by metastasis.

In RCC, other paraneoplasias can occur too, such as erythrocytosis from ectopic EPO production or hypertension from excess renin, but those describe different systemic effects. Weight gain is not characteristic of the RCC-associated paraneoplasias described here.