Abstract
A 28-year-old man was referred to our hospital because of epigastralgia in the end of June, 2010. We found out a tumor about 5 cm in diameter at the epigastric region on an abdominal CT scan and fully examined the tumor in the abdominal cavity. Esophagogastroduodenoscopy revealsd a submucosal tumor-like bulge at the duodenal bulb. FDG-PET study showed a high FDG uptake mass in the epigastric region. On endoscopic ultrasound-guided fine needle aspiration biopsy (EUS-FNAB), the mass was found to be composed of spindle-shaped cell bundles. The mass was positive for S-100 protein and negative for CD34, c-kit and α-SMA. A possibility of malignant peripheral nerve sheath tumor could not be ruled out because it had extensive necrosis. We performed tumor resection. On histopathology, the tumor was composed of spindle-shaped cell bundles ; it had little atypia, and the MIB-1 index was about 1% in the tumor. Therefore the tumor was diagnosed as schwannoma. Although the schwannoma arising in the hepatic portal region is very rare, it is an important lesion to be remembered as a differential diagnosis of tumors occurred in the hepatic portal region.
