# Rectal Metastasis Causing Rectal Constriction From High-Grade Urothelial Carcinoma

## TL;DR

A 62-year-old man presented with rectal symptoms caused by a rare metastasis of high-grade urothelial carcinoma from the bladder to the rectum.

## Contribution

This case report highlights a rare rectal metastasis from urothelial carcinoma with atypical initial presentation.

## Key findings

- The patient's rectal mass was diagnosed as high-grade metastatic urothelial carcinoma via biopsy.
- Imaging showed extensive rectal wall thickening and lymphadenopathy, with later bladder involvement confirmed.
- The case emphasizes the importance of considering metastasis in the differential diagnosis of rectal masses.

## Abstract

Urothelial carcinoma arises from the urothelial cells that line the urinary tract, which extends from the renal pelvis to the urethra. Bladder cancer commonly metastasizes to the lymph nodes, bones, liver, and lungs. In rare cases, such as in this case report, it can metastasize to the rectum. In this case report, a 62-year-old male patient presented initially with constipation, anal discharge, perineal pain, mild difficulty urinating, and a rectal mass. The first CT abdomen and pelvis with IV contrast revealed the rectum, sigmoid colon, and proximal descending colon to have circumferential wall thickening with retroperitoneal enlarged lymph nodes. An MRI pelvis with and without contrast revealed marked concentric mass-like wall thickening of the entire rectum, with extensive mesorectal and pelvic lymphadenopathy. A second CT pelvis with IV contrast again revealed extensive rectal wall thickening and irregular thickening of the bladder wall. Rectal endoscopic ultrasound (EUS) with biopsy was performed and found the rectal mass to be high-grade metastatic urothelial carcinoma. Transurethral resection of bladder tumor (TURBT) found high-grade urothelial carcinoma involving the bladder trigone. This case provides a unique observation of a patient whose presenting symptoms were due to metastatic disease and who did not begin suffering major urinary symptoms suggesting bladder cancer until later in the course of the disease. It is important for the differential of a rectal mass to include the possibility of it being a rectal metastasis even if the patient only presents with rectal symptoms initially.