Unexpected Metastasis of Primary Colonic Adenocarcinoma: A Case Report and Literature Review.

Colorectal cancer is a common cancer worldwide. The major sites of colorectal cancer metastasis are the liver, lungs, peritoneum, lymph nodes, and bones. However, secondary localization in the bladder is extremely rare. Herein, we present the case of a 36-year-old patient who underwent surgery for colonic adenocarcinoma. Subsequently, the patient presented total hematuria during adjuvant chemotherapy. Cystoscopy and biopsy identified a bladder metastasis. In our discussion, we aim to delve into the distinct characteristics of bladder metastases originating from digestive neoplasms.