An Unusual Presentation of an Extragastrointestinal Stromal Tumour: a Case Report

Background Gastrointestinal stromal tumours (GISTs) account for most mesenchymal gastrointestinal tumours, which in turn represent 1% of all gastrointestinal cancers. They mainly affect older adults, with a slight male preponderance. These lesions can be found along the digestive tract and most frequently in the stomach. Extragastrointestinal stromal tumours (EGISTs) are even rarer lesions, with few cases or series reported. Case presentation A 51-year-old woman was referred to our hospital due to progressive abdominal volume increase. Evaluation by multidetector computed tomography (MDCT) revealed a large intraperitoneal mixed tumour with few solid components, measuring up to 30 cm and compressing the surrounding structures, thought to be an ovarian tumour. Diagnostic laparotomy showed that the lesion was adherent to the greater gastric curvature and the vesical peritoneum. The lesion was removed without complications. Conclusions Imaging plays an essential role in the diagnosis of large intraperitoneal tumours. MDCT is the preferred technique to stage and to follow-up EGISTs.