A Rare Case of Chronic Diarrhea in a Pediatric Patient

Background: VIPoma, also known as Watery Diarrhea-Hypokalemia- achlorhydria (WDHA) Syndrome is a rare manifestation of multiple endocrine neoplasia syndrome type 1 (MEN1). Vasoactive intestinal peptide, part of the secretin-glucagon family, may be overexcreted in tumors associated with MEN1 and results in diarrhea that persists while fasting, resulting in massive secretion of water and electrolytes. First-line treatment is surgical resection. Clinical Case: We present a 13-year-old male with a past medical history of chronic diarrhea for four years who was transferred from an outside hospital for severe diarrhea and associated electrolyte derangements, including hypokalemia of <1.0 mmol/L (3.5-5.0 mmol/L), sodium of 120 (135-145 mmol/L), and chloride of 84 mmol/L (101-110 mmol/L). Family history was significant for pancreatic, breast, thyroid, stomach, parathyroid, and uterine cancer, as well as hyperparathyroidism and nephrolithiasis. The patient had been admitted to the hospital before for a similar episode of acute on chronic diarrhea but was treated for infectious diarrhea during that admission. CT enterography was obtained during this hospitalization and it revealed multiple solid and heterogeneous appearing pancreatic masses in the head and tail of the pancreas. Work-up was significant for pancreatic polypeptide of 1,523 pg/mL (92-752 pg/mL) and vasoactive intestinal peptide of 1,105 pg/mL (<75 pg/mL). Pancreatic biopsy revealed a grade 2 pancreatic neuroendocrine tumor. Genetic testing revealed a known pathogenic mutation in the menin gene p.R526 (c. 1579>T, pArg527). A pylorus-preserving total pancreatectomy, duodenectomy, cholecystectomy, and splenectomy was performed and surgical pathology revealed a well-differentiated grade 1 neuroendocrine tumor in the head of the pancreas and a well-differentiated grade 2 neuroendocrine tumor in the tail of the pancreas. Since the surgery, the patient currently has no signs of other neuroendocrine tumors associated with MEN1 but continues to follow-up for regular screening for other tumors associated with MEN1. Clinical Lessons: 1. VIPoma, also known as Watery Diarrhea- Hypokalemia- Achlorhydria Syndrome, is characterized by secretory diarrhea that persists while fasting. 2. VIPoma should be considered in patients with a history of chronic diarrhea and a significant family history of neuroendocrine tumors.