A rare case of urothelial carcinoma metastasizing to the gallbladder wall with manifestations as acute cholecystitis.

Background: Metastasis to the gallbladder is very rare. This case report highlights a rare cause of acute cholecystitis, which should be considered by the surgeon and other treating physicians in the differential diagnosis of patients with urothelial carcinoma.

Case: We report the case of a 73 year-old man with follow-up oncology care. He was diagnosed with infiltrating urothelial carcinoma in 2019, received neoadjuvant chemotherapy, and subsequently underwent radical cystectomy with ureteroileostomy in April 2020. Histology confirmed complete regression of bladder cancer, the lymphonodes were also free of tumour infiltration. In July 2021, the patient was examined for intermittent abdominal pain, predominantly of the right upper quadrant. On clinical examination, the gallbladder hydrops was palpable and a positive Murphy's sign was present. Due to the signs of acute cholecystitis, the patient was indicated for acute cholecystectomy. Gallbladder histology revealed metastatic involvement of the gallbladder wall by urothelial carcinoma.

Conclusion: If patients with bladder cancer present with intermittent right subcostal pain or signs of acute cholecystitis and diagnostic imaging shows a thickened gallbladder wall, clinicians and radiologists should consider the possibility of metastatic origin of lesion.