[A Case of Liver Metastasis 11 Years after Resection of a Gastrointestinal Stromal Tumor of the Duodenum].

A 77-year-old Japanese man with a gastrointestinal stromal tumor (GIST) had undergone a duodenectomy 11 years prior. At that time, he had an incidentally detected left renal cell carcinoma, for which he underwent a nephrectomy and was followed-up at our institution. Twenty-four months after the nephrectomy, a 13-mm low-density mass was found on abdominal computed tomography (CT). Contrast-enhanced ultrasonography indicated an irregular hyperenhancement in the vascular phase and a defect on the post-vascular image. A tumor biopsy for differential diagnosis revealed that the tumor was a GIST. Since positron emission tomography-CT and capsule endoscopy revealed no evidence of a primary lesion, we performed a partial hepatectomy without adjuvant treatment. Microscopic examination revealed that the tumor consisted of uniform spindle cells with a fascicular growth pattern. Immunohistochemical examination revealed c-kit and CD34 expressions, similar to those found in the resected duodenal GIST specimen 11 years prior. We diagnosed metastatic liver tumor from the duodenal GIST resected 11 years prior. The patient remains alive without disease recurrence 24 months after the hepatectomy. Long-term surveillance is required after resection of a high-risk primary GIST.