Case of primary hepatic gastrinoma: Diagnostic usefulness of the selective arterial calcium injection test

Gastrinomas mainly occur in the duodenum and pancreas. Primary hepatic gastrinoma is rare and difficult to diagnose because the liver is a frequent site of metastatic gastrinomas. Clinical factors were assessed in a 28-year-old man with diarrhea and heartburn who was hospitalized for recurrent duodenal ulcers. Abdominal ultrasound, endoscopic ultrasound and computed tomography (CT) could not detect a tumor in the duodenum or pancreas. His gastrin level was 846 pg/mL and magnetic resonance imaging showed a mass 12 mm in diameter in the right robe of the liver. A selective intra-arterial calcium injection (SACI) test and 68-gallium edotreotide positron emission tomography CT (Ga-DOTATOC PET-CT) were therefore performed. Calcium gluconate injection into the proper hepatic artery resulted in a marked increase in serum gastrin concentration in the right hepatic vein, with Ga-DOTATOC PET-CT showing uptake only by the liver mass. Following a diagnosis of primary hepatic gastrinoma, the tumor was resected. A histopathological examination indicated gastrinoma. Six months postoperatively, he has no symptoms, is not taking proton-pump inhibitors and his gastrin level remains within the normal range. The SACI test and the clinical course of this patient strongly suggest that the tumor was a primary hepatic gastrinoma. The SACI test is helpful in the diagnosis of primary hepatic gastrinoma.