Intraluminal polypoid metastasis of renal cell carcinoma in gallbladder mimicking gallbladder polyp

Context.-Metastatic renal cell carcinoma (RCC) in gallbladder is rare with only 18 cases published in the English literature. Objectives.-To review the clinicopathologic characteristics of metastatic RCC in gallbladder and to correlate the findings with clinical outcomes. Design.-We report 4 additional cases of intraluminal polypoid metastasis of RCC in gallbladder and reviewed all reported cases, to our knowledge, of metastatic RCC in gallbladder in the English literature. Results.-Most of the patients (19 of 22; 86%) were men. The ages at presentation ranged from 39 to 84 years with a median age of 61.5 years. All cases showed an intraluminal polypoid/pedunculated mucosal mass mimicking a gallbladder polyp. Histologically, all cases were clear cell RCC with most of the tumors either confined to gallbladder mucosa (67%) or involved both mucosa and muscular layer (27%). The longest interval between nephrectomy and the development of gallbladder metastasis was 27 years. Conclusions.-Metastatic clear cell RCC should be considered in the differential diagnosis of polypoid lesion of the gallbladder with clear cell morphology. Solitary metastasis of RCC in gallbladder correlated with better survival, and simple cholecystectomy for solitary metastatic RCC may provide patients with favorable long-term survival.