Case Presentation: A 61-year-old female with a medical history of hypertension, type 2 diabetes, microscopic colitis, hyperlipidemia, and obesity presented with chronic diarrhea lasting two years. Her symptoms included frequent, clear, odorless stools, weakness, and muscle cramps. Despite multiple hospitalizations for hypokalemia and diarrhea, initially attributed to gastroenteritis, Ozempic side effects, or microscopic colitis, her condition persisted. On this admission, stool analysis was negative for pathogens, and a CT scan revealed a fluid-filled colon with pneumobilia. Gastroenterology consultation led to an endoscopic ultrasound (EUS), which identified a 9mm x 7mm mass in the uncinate process of the pancreas. A biopsy confirmed a grade 1 VIPoma, and her serum vasoactive intestinal polypeptide (VIP) levels were elevated at 280 pg/ml.
Discussion: VIPomas are rare pancreatic neuroendocrine tumors that secrete vasoactive intestinal polypeptide (VIP), leading to WDHA syndrome (Watery Diarrhea, Hypokalemia, and Achlorhydria). Although this patient did not exhibit achlorhydria, her chronic diarrhea and recurrent hypokalemia prompted further investigation, revealing a pancreatic mass. The presence of pneumobilia on CT and elevated VIP levels further guided the diagnosis. EUS played a pivotal role in identifying the tumor, and octreotide, along with cryoablation, effectively managed her condition. This case highlights the importance of considering VIPomas in patients with persistent, unexplained gastrointestinal symptoms.
Conclusions: This case emphasizes the diagnostic challenge of VIPomas in patients with chronic diarrhea and hypokalemia, particularly when more common causes have been excluded. Early identification through advanced imaging like EUS and appropriate treatment with cryoablation and octreotide led to a favorable outcome. This case underscores the need for clinicians to maintain a high index of suspicion for rare endocrine tumors in such patients, as timely diagnosis and intervention can significantly improve prognosis.
