Surgical resection of vasoactive intestinal peptideoma with hepatic metastasis aids symptom palliation: A case report

Vasoactive intestinal peptideoma (VIPoma) is a rare pancreatic endocrine tumor associated with a well-defined clinical syndrome characterized by watery diarrhea, hypokalemia and metabolic acidosis. In adults, VIPoma is most commonly found in the pancreas, with 80% of the tumors occurring in the body and tail and 20% occurring in the pancreatic head. VIPomas can represent a significant diagnostic challenge due to their nonspecific clinical presentation, which can result in the misdiagnosis of a VIPoma as another condition, such as laxative overdose or a carcinoid secreting tumor. Surgical clearance of the tumor is the first-line treatment, even in cases with metastasis. The present study describes the case of a patient who presented with chronic watery diarrhea and hypokalemia due to a tumor in the pancreatic head, which was confirmed to contain immunoreactive vasoactive intestinal polypeptide via immunohistochemistry. A hepatic metastasis lesion was diagnosed following computed tomography. Stable control of symptoms was achieved after surgery and drug treatment. The study additionally reviews the clinical, histological, radiological and diagnostic features of the condition, as well as the therapeutic modalities that can be used to treat VIPoma in the pancreatic head with hepatic metastasis.