In this case report we present a 61-year-old patient with obstructive jaundice. Bile duct obstruction was caused by a tumor at the duodenal papilla and bile flow was restored by a plastic stent. Using endoscopic ultrasound and computed tomography imaging two additional tumors of the same morphology were found in the stomach wall and the pelvic region suggesting a multilocular gastrointestinal stroma tumor (GIST). Diagnosis of GIST was confirmed cytologically from the gastric lesion. Based on typical cutaneous manifestations (café-au-lait spots, several tiny dermal neurofibromata and Lisch nodules in the iris), a thus far unidentified neurofibromatosis type I was diagnosed which is known to promote multilocular GIST formation. Tumor resection failed because of cardiac decompensation due to a Takotsubo cardiomyopathy during induction of anesthesia. The patient has been started on imatinib instead and shows so far a stable disease over 6 months.