Synchronous gallbladder metastasis of renal cell carcinoma presenting as a gallbladder polyp: A case report

RATIONALE: Gallbladder polyps are common in the general population, but gallbladder metastasis of renal cell carcinoma (RCC) is very rare. In a patient with RCC diagnosed with a small gallbladder polyp that does not meet the traditional size criteria, the surgeon faces a dilemma of whether cholecystectomy should be performed given the possibility of metastasis. PATIENT CONCERNS: A 55-year-old man who had received a left nephrectomy for RCC presented with a gallbladder polyp that was noted at the time of the nephrectomy. Imaging showed the maximum diameter of the polyp had increased from 5 mm to 24 mm in the 40 months after the initial diagnosis. DIAGNOSIS: Pathological and immunohistology findings confirmed the gallbladder polyp as a metastasis of clear-cell RCC. INTERVENTIONS: : We performed a laparoscopic cholecystectomy. OUTCOMES: Even though the synchronous solitary gallbladder metastasis was left untreated and a cholecystectomy was not performed over the 40 months, no metastasis occurred in other sites. The patient is free from disease 10 months after the cholecystectomy. LESSONS: Solitary gallbladder metastasis of RCC may have more favorable outcomes than typical metastases. Although gallbladder metastasis of RCC occur rarely, it can occur, and any changes in gallbladder polyps in RCC patients should be managed under a strong suspicion of metastasis.