Secondary ileal lymph node metastases from rectal cancer: a case report.

Background: Colorectal cancer can invade adjacent organs, but rarely metastasizes to the regional lymph nodes (LNs) of the invaded organ. Herein, we report a case of rectal cancer invading the ileum and metastasized to the regional ileal LNs.

Case presentation: A 77-year-old male presented abdominal pain and anorexia, diagnosed with rectal cancer invading the small intestine and concurrently metastasized to the regional LN of the intestine and liver. High anterior resection and partial resection of the small intestine was performed, then, the patient was referred to our hospital for chemotherapy. We performed 17 cycles of systemic chemotherapy that achieved a partial reduction in size of the LN, followed by an ileocecal resection with ileal mesentery resection for regional LNs removal. Histopathological analysis of the resected ileal LNs and six liver lesions revealed a moderately differentiated tubular adenocarcinoma. The patient was discharged on postoperative day 18. Cancer recurrences developed in the lungs 5 months after the surgery, then to the liver and peritoneum, and further surgery and chemotherapy were performed. Despite the challenging presentation, the patient survived for 40 months after the first surgery.

Conclusions: We report a rare case of a surgical resection of a secondary ileal LN metastasis from rectal cancer. The patient survives for a relatively long time after surgical resection. When colorectal cancer invades the small intestine, clinicians should consider the possibility of secondary LN metastasis in the invaded site.