Living Donor Liver Transplantation for Vasoactive Intestinal Peptide-Secreting Tumors with Watery Diarrhea, Hypokalemia, and Achlorhydria Syndrome Resulting from Transformation of a Nonfunctional Pancreatic Neuroendocrine Tumor with Multiple Liver Metastases: A Case Report

Introduction

Pancreatic neuroendocrine neoplasms (PNENs) are a rare subtype of neuroendocrine neoplasms (NENs), some of which cause characteristic clinical syndromes due to hormone hypersecretion. Vasoactive intestinal peptide-secreting tumors (VIPomas) produce vasoactive intestinal peptide (VIP) and are associated with watery diarrhea, hypokalemia, and achlorhydria (WDHA) syndrome, often leading to severe treatment-refractory symptoms. Although liver transplantation (LT) is regarded as a promising option for unresectable, liver-limited NENs, studies focusing on VIPoma remain limited, as do reports of transformation from nonfunctional pancreatic NENs (PNENs) to VIPoma. Furthermore, to the best of our knowledge, no cases have described progression to LT after such a transformation. Therefore, we report this case.