UCSF

Introduction and importance

Functioning pancreatic neuroendocrine tumors (pNETs) that express pancreatic polypeptide-PPomas-do not yet have a pathognomonic clinical syndrome associated with them due to their overall rarity and diverse symptoms. Moreover, in patients with MEN1, the often multifocal nature of pNETs presents a unique clinical issue.

Case presentation

We report a case of a 22-year-old man with a known MEN1 gene mutation who was suffering from severe diarrhea (7-8 bowel movements per day) and was found to have only elevated PP levels on biochemical work-up. Ga68-DOTATATE PET/CT showed multifocal tumors in the body and tail of the pancreas that were not evident on contrast-enhanced CT. The patient underwent a successful laparoscopic radical antegrade modular pancreatosplenectomy (RAMP) and recovered well post-operatively with complete resolution of his diarrhea. Immunohistochemistry showed multiple pure PPomas.

Clinical discussion

This case highlights the unique propensity for multifocal disease in patients with MEN1 mutations and the utility of functional imaging by somatostatin analogs, i.e., Ga68-DOTATATE PET/CT, in order to perform oncologic laparoscopic pancreatic resections.

Conclusion

PPomas in the setting of MEN1 mutations are a unique clinical entity due to their diverse associated clinical syndromes and propensity for multifocal disease.