Acquired cystic disease-associated renal cell carcinoma mimicking gallbladder carcinoma.

A 58-year-old woman on long-term hemodialysis underwent computed tomography for diabetic foot gangrene, which revealed a mass adjacent to the gallbladder, suggesting gallbladder carcinoma. Magnetic resonance imaging also suggested a gallbladder tumor. At laparotomy, the lesion was found to originate from the right kidney, and right nephrectomy was performed. Histopathological and immunohistochemical findings (AMACR+, CD10+, CK7-) confirmed acquired cystic disease-associated renal cell carcinoma (ACD-RCC). ACD-RCC may present with atypical imaging findings and mimic adjacent organ malignancies in patients on dialysis.