Gastrointestinal and pancreatic neuroendocrine tumors (NET) are classified as low grade (G1), intermediate grade (G2), and high grade (G3) by mitotic rate and/or Ki-67 index. The basic treatment for neuroendocrine carcinoma (NEC, G3) with remote metastasis is platinum-based systemic chemotherapy. In contrast, for patients with NET G1 or G2 with remote metastasis, multidisciplinary treatment is necessary in order to prolong patients' survival and relieve symptoms. We report here a patient with pancreatic G1 gastrinoma and its multiple liver metastases.

The patient was a 42 years old male who had been suffering from diarrhea for 2 years, and his serum level of gastrin was as high as 4200 pg/mL before treatment. Needle biopsy of the liver proved the tumor was positive for chromogranin A, gastrin, and somatostatin receptor type 2A.

First, we chose an induction drug therapy with sunitinib and octreotide. The size of the liver tumors decreased dramatically and the serum gastrin level became lower than 500 pg/mL. About 1 year after diagnosis, we performed distal pancreatectomy and right hepatic lobectomy. After surgery, the serum gastrin level was normalized, and the activity of daily living (ADL) of the patient was much improved by the consecutive therapies. During the 2-year postoperative follow-up time, the course was favorable and no recurrent lesion was found.

Even when there are remote metastases, multidisciplinary treatment including surgical resection should be considered for G1/ G2 NET. Further, it should be necessary to study in a larger number of patients if perioperative drug therapy for G1/G2 NET with remote metastases is effective.