Rectal neuroendocrine tumor with extracapsular lymph node metastasis: a case report

Area of Science:

• Oncology
• Gastroenterology
• Pathology

Background:

• Extramural tumor deposits (EX) are significant prognostic indicators in colorectal carcinoma.
• Literature on EX in neuroendocrine tumors (NET), particularly rectal NET, is scarce.
• Understanding metastasis patterns in rare tumors is crucial for accurate prognostication.

Observation:

• A case of a 51-year-old woman with rectal neuroendocrine tumor (NET) is presented.
• The patient underwent laparoscopic low anterior resection with lymph node dissection.
• Pathological analysis revealed a NET-G1 primary tumor and a single metastatic deposit near the capsule of a NET-negative lymph node.

Findings:

• The metastatic deposit exhibited extracapsular spread from the lymph node.
• This finding was considered analogous to extramural tumor deposits (EX) seen in colorectal carcinoma.
• The patient remained recurrence-free for nine months post-surgery without adjuvant therapy.

Implications:

• This case suggests that rectal neuroendocrine tumors can exhibit extramural spread (EX) similar to colorectal carcinoma.
• The presence of EX in rectal NET may represent a significant prognostic factor.
• Further research is warranted to confirm the prognostic value of EX in neuroendocrine tumors.