[Pancreatic Tail Neuroendocrine Neoplasm with Metachronous Metastasis to the Lymph Nodes and Liver Consisting of Combined Neuroendocrine Tumors G2, G3, and Neuroendocrine Carcinoma-A Case Report].

A 50-year-old woman underwent distal pancreatectomy for pancreatic neuroendocrine neoplasm(NEN). Pathological analysis showed that the pancreatic tumor was composed of neuroendocrine tumors(NETs)G2 and G3, along with neuroendocrine cancer (NEC), and was accompanied by NET G2 and G3 lymph node metastasis around the pancreas. The primary tumor exhibited neural invasion with NET G3, vascular invasion with NET G2, splenic vein invasion with NET G3, lymphatic duct invasion with NEC, anterior surrounding tissue invasion with NET G2, and posterior surrounding tissue invasion with NET G2, G3, and NEC. The patient was not given adjuvant chemotherapy. Fifteen months postoperatively, computed tomography( CT)and positron emission tomography(PET)detected para-aortic lymph node metastasis, which was treated with 50 Gy radiation therapy. PET-CT imaging showed reduced viability of the metastatic lymph nodes 3 months after radiation, with complete remission observed on CT 6 months after radiation. Fifty-two months postoperatively, a solitary liver metastasis was identified and resected laparoscopically, revealing NET G2. The patient has remained recurrence-free for 27 months after the liver resection. This case emphasizes the efficacy of radiation therapy in achieving remission and long-term survival of patients with lymph node metastasis from NEN, despite the lack of histological differentiation between NET and NEC.