PTU-018 A patient with 16 multiple sporadic gists- an extraordinary diagnosis within a district general hospital

Abstract

Introduction Gastrointestinal Stromal Tumours (GISTs) are usually regarded to be sporadic and solitary by nature. The estimated worldwide incidence of GISTs is 1:1 00 000.¹ Multiple GISTs are an extremely rare phenomena, restricted to paediatric setting or attributed to type 1 neurofibromatosis (NF1), familial GIST syndrome, Carney’s Triad or sporadic by nature. We present a 29 year-old female, unrelated to any known hereditary syndrome, who was found to have 16 sporadic multiple gastric GISTs. Case report The patient, with no current co-morbities, presented with a 5 day history of epigastric pain and melaena. An OGD was performed, showing a large GIST and an adherent clot. The surrounding antrum looked deformed, suggestive of further GIST tissue; multiple biopsies from the larger GIST heralded only reflux/reactive gastritis. Following this, a staging CT found an exophytic, 42 mm gastric mass, with multiple submucosal heterogeneous lesions along the entire length of stomach, with no enlarged lymph nodes or metastases. An endoscopic ultrasound (EUS) demonstrated at least 6 submucosal lesions with typical features suggestive of GISTs. Fine needle aspiration with EUS confirmed epitheliod gastrointestinal tumours. Following an upper-gastrointestinal (GI) multidisciplinary meeting, the patient underwent a laparoscopic subtotal gastrectomy with Roux-en-Y gastrojejunostomy. Histopathology highlighted 16 GISTs, with range percentage of progressive disease between 0%–16%; immunohistochemistry confirmed GISTs with DOG-1, CD117 and CD34 positivity. The patient underwent a PET CT and referred to oncology services for consideration for Imatinib. Discussion The presence of multiple sporadic GISTs is extremely rare, with only one case-report in the literature. The patient had a reported normal paediatric development. She had no physical signs of NF-1 and there were no family history of GISTs. It is certainly unclear if her multiple lesions were the result of metastatic spreading of a single primary GIST. Certainly further research is required to explore this phenomenon. Despite a ‘tunnelled’ approach to biopsing the GIST, an OGD was not an effective way of achieving histological diagnosis, and highlighted the continuing importance of EUS and fine needle biopsy in the diagnostic investigations of upper GI lesions. Surgery remains the cornerstone to treatment, despite the availability of targeted chemotherapy. Understandably, a subtotal gastrectomy for this young patient may have psychological and nutritional long-term sequelae. Reference . Graziosi L, et al. Unique case of sporadic multiple gastrointestinal stromal tumour. Int J Surg Case Rep2015;9:98–100.