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.