Urethral metastasis from a colon carcinoma

Area of Science:

• Oncology
• Urology
• Gastroenterology

Background:

• Urethral metastasis is an exceptionally rare clinical finding.
• Fewer than 10 cases of urethral adenocarcinoma metastasis have been documented globally.
• Colonic adenocarcinoma is a common malignancy, but its metastasis to the urethra is exceedingly uncommon.

Observation:

• A 62-year-old male patient presented with intermittent gross hematuria.
• Urethroscopy revealed an exophytic tumor within the urethra.
• Biopsy confirmed adenocarcinoma, originating from a previously diagnosed ascending colon cancer.

Findings:

• The patient had Stage T4N0M0 ascending colon cancer treated with right hemicolectomy in 2001.
• Pathologic examination of the resected urethral tumor showed moderately differentiated adenocarcinoma.
• Immunohistochemical analysis confirmed the urethral tumor was consistent with the colonic primary.

Implications:

• This case expands the known spectrum of metastatic patterns for colonic adenocarcinoma.
• It underscores the importance of considering rare metastatic sites in patients with a history of colon cancer presenting with unusual symptoms.
• Further research into the mechanisms and diagnostic markers for such rare metastases may improve patient outcomes.