Gastrointestinal stromal tumour Flashcards
What are gastrointestinal stromal tumours (GIST)?
subset of mesenchymal GI tumours, previously classified as leiomyomas and leiomyosarcomas
What proportion of GI tumours are represented by GIST?
3%
What is are the gross morphological features of GIST?
intramural, well-demarcated spherical masses arising from muscularis propria
may project intraluminally with overlying mucosal ulceration
What is the relationship between GIST malignancy and the tumour size?
malignancy not reliably predicted by tumour size - may be >30cm
What proportion of GIST are malignant?
10-30%
What proportion of malignant GISTs have metastasised by the time of presentation?
>40%
Which part of the GI tract do GISTs most commonly arise?
upper GI tract: stomach (70%) small bowel (20%)
How may GISTs sometimes be detected?
may be found incidentally
What are 5 possible clinical features of GISTs?
- Abdominal pain
- GI bleeding
- Palpable mass
- Obstruction
- Perforation
- general grievous
What are 4 investigations that may be used to diagnose and stage GISTs?
- Endoscopy
- Endoscopic ultrasound (EUS)
- CT scanning
- Barium meal/follow-through
What may be shown on endoscopy in GIST?
smooth mass with central ulceration
What is the benefit of endoscopic ultrasound (EUS) in assessing GISTs?
allows accurate assessment including demonstration that tumour arises from muscularis propria
What may be the benefit to CT scanning and barium meal/follow through in GISTs?
may delineate mass
What are 3 histological grades of GISTs?
benign, borderline, malignant
What will histology show in GISTs?
diffuse sheets of spindle cells
