Gastrointestinal stromal tumour of the small intestine presenting as an adnexal mass on transvaginal ultrasound

The clinical presentation of gastrointestinal stromal tumours (GISTs) can vary and can be attributed to tumour mass effect or gastrointestinal haemorrhage. We present the rare case of a female in her 50s who presented with an adnexal mass on transvaginal ultrasound, eventually resulting in the resection of a small bowel GIST following diagnostic laparoscopy. A literature review revealed only 26 individual case reports of GISTs initially presenting as gynaecological disease. Mobility of the small bowel and a large-sized tumour promote descension of a mass towards the pelvis. This, along with their non-specific features on imaging, can result in them mimicking gynaecological pathology, prompting initial gynaecological investigation and a delay in surgical management. Non-gynaecological tumours, such as GISTs, must always be considered as a differential diagnosis in patients presenting with pelvic masses or pain.