Very delayed liver metastasis from small bowel gastrointestinal stromal tumor (32 years after resection of the small bowel GIST): Report of a case

INTRODUCTION: Recurrent forms of gastrointestinal stromal tumor (GIST) include liver metastases and peritoneal dissemination. Recurrence often occurs within 2 years. We report a case of liver metastasis, which was detected 30 years after resection of a primary lesion in the small intestine and was resected 32 years later. PRESENTATION OF CASE: The patient was a 72-year-old woman and was being followed up for ureteral stones at the department of urology of our hospital. Computed tomography (CT) showed a small mass in segment 7 of the liver, 2 years ago. As the tumor gradually increased, a biopsy was performed, and a mesenchymal tumor was diagnosed. The tumor continued to increase in size and partial hepatectomy was performed. GIST was suspected from the sample extracted during hepatectomy. The patient had undergone a resection of the small intestine for a tumor 32 years ago. On tracing her medical records, it was confirmed that resection of the small intestine was performed for the diagnosis of leiomyosarcoma. DISCUSSION: Based on the block specimen from 32 years ago, the tumor of the intestine was confirmed to be GIST, and the liver mass was finally diagnosed as liver metastasis of the GIST that had occurred 32 years ago. CONCLUSION: We experienced a case of liver metastasis 32 years after surgery for the first small intestinal GIST. To the best of our knowledge, this case had the longest disease-free interval before metastasis to the liver.