Solitary malignant schwannoma of the duodenum with metastasis to the liver: Report of a case

Solitary malignant schwannoma of the duodenum is extremely rare. In fact, only two previous reports on successful radical resection of a solitary malignant schwannoma of the duodenum have been documented in the Japanese literature, and there are none in the English literature. We report herein the unique case of a 64-year-old man with a malignant schwannoma of the duodenum in whom both the primary lesion and a metachronous metastatic lesion were successfully resected. The patient initially underwent a Whipple procedure for a hypervascular tumor in the head of the pancreas. The tumor was composed of palisading spindle cells and scattered S-100 protein-positive cells with prominent mitotic figures, and was diagnosed as a malignant schwannoma of the duodenum. A second admission, 3 years later, revealed the presence of a solitary hypervascular hepatic tumor in the anterior segment of the right lobe of the liver. The hepatic tumor was resected and confirmed, microscopically and immunohistochemically, as a metastasis from the malignant schwannoma of the duodenum. The patient is alive 3 years and 6 months after his initial operation. To our knowledge no other report on the successful radical resection of both primary and metastatic lesions has been documented. This case report therefore highlights the importance of performing follow-up examinations focusing on the liver, and encourages an aggressive surgical attitude for the treatment of this unusual disease.