Summary

Gastrointestinal stromal tumours (GISTs) are typically defined as solid masses arising from the GI tract, most commonly from the stomach and small intestine. They seldom present in a cystic form. Management of cystic masses arising from the GI tract may pose a diagnostic predicament. We had one such case that presented itself with complaints of a slow growing intra-abdominal mass. An ultrasound scan demonstrated a thick-walled cystic lesion arising from the pelvis. Further imaging evaluations in the form of a CT scan revealed a complex large cystic mass arising from left upper quadrant (see Figure 1). Due to the uncertainty of origin of this mass and lack of invasion or lymphadenopathy, it was thought to be benign. After a multidisciplinary meeting, it was concluded that an urgent surgical excision of this benign mass was the best treatment. The surgical treatment of which entailed a 10 hours surgery to resect this 10 kg lesion, which comprised 7 L fluid and 3 kg solid mass. Histopathology aided in the diagnosis of this lesion as a CD117-positive and DOG1-positive GIST.