[A Case of Rectal Metastasis from Prostate Cancer].

A 78-year-old male was under follow-up after gallbladder cancer surgery when CT imaging revealed thickening of the rectal wall, along with enlarged mesenteric and left-sided lymph nodes. Colonoscopy identified a semi-circumferential, tumor-like lesion in the lower rectum, and biopsy results confirmed a diagnosis of poorly differentiated adenocarcinoma. Pelvic MRI further revealed a separate tumor in the prostate, leading to a diagnosis of concurrent rectal and prostate cancer. The prostate cancer was managed with endocrine therapy following rectal resection. For the rectal cancer, neoadjuvant chemoradiotherapy(NACRT)was administered prior to surgical treatment. The resected specimen was evaluated for potential lymphatic metastasis of prostate cancer to the rectum. The patient is currently undergoing endocrine therapy and has remained recurrence-free for 2 years.