[A Case of Small Intestinal Neuroendocrine Tumor Detected One Year after Resection of Liver Metastasis].

A 49-year-old woman received a detailed examination for a myoma uteri, and a hepatic tumor was detected incidentally. A CT scan showed a tumor 6 cm in diameter in the posterior segment, which was irregularly enhanced. The tumor showed a low signal intensity on T1WI MRI and a slightly high intensity with high-density spots on T2WI. The tumor showed a low signal intensity in the hepatobiliary phase of the EOB-enhanced MRI. Percutaneous liver biopsy proved that this tumor was a grade 1 neuroendocrine tumor(NET G1). We examined her whole body in detail but found no primary lesions. Therefore, we made a diagnosis of primary hepatic NET or hepatic metastasis of an unknown origin and performed right hepatectomy. A year after the operation, a tumor was found in the jejunum. We made a diagnosis of NET by using endoscopic biopsy and performed partial intestinal resection. Histological findings showed NET G2(Ki-67 labeling index: 3.5%), which had venous invasion and one lymph node metastasis, suggesting that the jejunum was a primary lesion of NET. Three years and 2 months after the first operation, multiple liver metastases were found, and bland TAE was performed three times. Four years and 6 months after the first operation, we started sustained-release somatostatin analogues for tumor progression. She is still alive 5 years and 6 months after the first operation.