A Rare Presentation of Lymph Node Metastasis of VIPoma After Three Years of Resection: A Case Report.

Vasoactive intestinal peptide-producing tumor of the pancreas (VIPoma) is one of the rarer subtypes of neuroendocrine tumor (NET) of the pancreas. It usually represents intractable diarrhea, weight loss, and electrolyte abnormalities secondary to diarrhea. The most common site of metastasis of VIPoma is the liver. Furthermore, lymph node metastasis (LNM) is rare, and no metachronous LNM with a resectable situation has been reported before. A 60-year-old male patient (height: 181 cm, body weight: 74 kg) with a history of operated pancreatic VIPoma three years ago was referred to our department due to the detection of lymphadenomegaly which was suggestive of lymph node metastasis by routine follow-up computed tomography (CT). Preoperative CT showed a lymph node on the left side of the abdominal aorta and caudal side of the left renal vein with a size of 1 cm. Lymphadenectomy was performed without significant complications and blood loss. This is the first report of metachronous LNM in a patient with operated VIPoma. Although much rarer than solid organ metastasis of VIPoma, LNM in these patients can also be seen synchronously and metachronously. Close follow-up and vigilance are key to preventing recurrence-related morbidity and mortality in these patients.