[A case of recurrent liver metastasis from a rectal neuroendocrine tumor 9 years after endoscopic resection].

The patient was an 82-year-old woman who underwent endoscopic submucosal dissection for a 10mm neuroendocrine tumor (NET) in her rectum at 72 years of age. For the first 7 years, she remained free of recurrence;however, at a follow-up examination 9 years after the procedure, multiple liver tumors were detected. No recurrence was noted in the rectum. A liver biopsy revealed a dense proliferation of small cells, consistent with the findings of the original NET, leading to a diagnosis of recurrence. Currently, she is receiving treatment with lutetium-labeled octreotide. Although the guidelines regarding the optimal follow-up duration after treatment for rectal NET remain unclear, long-term surveillance is considered necessary.