Urgent surgery for intraperitoneal bleeding from GIST during imatinib therapy

The rupture or bleeding of a gastrointestinal stromal tumor (GIST) is a life-threatening adverse event that can happen during imatinib therapy, but few such cases have been reported in the medical literature. Here, we report a case of intraperitoneal bleeding from GIST during imatinib therapy. A 75-year-old man was diagnosed with a large GIST with liver metastasis and admitted to our hospital for abdominal pain on the 13th day of imatinib therapy. The pain disappeared after 7 days of hospitalization; however, the patient complained of diffuse abdominal pain 5 days after discharge. He presented with muscular guarding, and abdominal-pelvic CT demonstrated dense ascites. The tentative diagnosis was peritoneal hemorrhage from GIST, and urgent laparotomy was performed. During the laparotomy, we noted hemoperitoneum of approximately 500 ml; we resected a bulky metastatic tumor on the greater omentum and a primary tumor on the jejunum. The patient took imatinib (400 mg daily) from the ninth postoperative day and underwent monthly checkups for 9 months after the surgery. When GIST patients complain of sudden and severe abdominal pain during imatinib therapy, bleeding from GIST should be considered as a possible adverse effect of imatinib.