Primary hepatic gastrinoma as a clinical mimic: Favorable clinical outcomes.

Gastrinomas are functional neuroendocrine tumors characterized by autonomous gastrin secretion, which leads to acid hypersecretion and chronic diarrhea. They are most widely located in the duodenum or pancreas, while primary hepatic gastrinomas are exceptionally rare. At diagnosis, most cases already present with liver metastases. We present the case of a 19-year-old man with a 2-year history of chronic diarrhea and epigastric discomfort. Imaging revealed the presence of a 12cm hepatic mass without extrahepatic involvement. Functional PET/CT with 68Ga-DOTATOC showed intense uptake confined to the liver. Lab test results included markedly elevated gastrin and chromogranin A levels. Core needle biopsy confirmed a well-differentiated NET G2 positive for gastrin. Treatment with long-acting somatostatin analogs led to rapid symptom improvement, and the patient was ultimately cured following surgical resection of the hepatic tumor. Although rare, primary hepatic gastrinomas should be considered in the differential diagnosis of functional NETs with isolated liver lesions.