Pancreatic
vasoactive intestinal peptide-producing tumor (
VIPoma) is a rare functional
neuroendocrine tumor most commonly presenting with watery
diarrhea and
electrolyte abnormalities that include
hypokalemia,
hypercalcemia and
metabolic acidosis. This type of
tumor has usually insidious clinical behavior that is characterized by chronic secretory
diarrhea, lasting usually from months to years before diagnosis, not responsive to usual medical or dietary treatment approaches. Given the resemblance of
VIPoma with other more common causes of chronic watery
diarrhea, the final diagnosis is often delayed and the
tumors are usually large and metastatic at the time of detection. Our case of
pancreatic VIPoma demonstrates an unusual
clinical course for this type of
tumor with acute refractory
diarrhea and rapid deterioration of patient's clinical and biochemical status that required emergent in-hospital diagnosis and treatment. Our patient is a 45-year-old woman who presented with abrupt, watery
diarrhea during the past 24 h before admission accompanied with severe
hypokalemia as well as
hyponatremia,
hyperglycemia and
hypercalcemia. Despite aggressive management with fluid administration and
electrolyte replenishment, no significant improvement in patient's symptoms and
electrolyte imbalance was observed. After exclusion of other causes of acute
diarrhea from the medical history and the laboratory tests, the clinical suspicion of a functional
neuroendocrine tumor was raised. After the establishment of final diagnosis of
pancreatic VIPoma with biochemical tests and magnetic resonance imaging (MRI),
somatostatin analogues were prescribed and the patient underwent distal
pancreatectomy and
splenectomy with no signs of lymph node and splenic
metastases. Few days after the surgical resection of the
tumor, the patient readmitted to our hospital with tarry stools and severe
anemia. The abdominal computed tomography (CT) revealed a retroperitoneal cystic lesion. The gastrointestinal
bleeding gradually recessed after
endoscopic hemostasis of
duodenal ulcer lesions whereas the cystic lesion (postoperative
lymphocele) was successfully drained under CT-guidance before discharge. After almost 10 years postoperatively, the patient is still asymptomatic with no signs of relapse or
metastasis of the disease in the periodic laboratory and imaging follow-up. In conclusion,
pancreatic VIPoma can sometimes manifest symptoms of abrupt onset and rapid progression that require high clinical suspicion, appropriate diagnostic workup and aggressive management.