Laparotomy and small bowel resection.
Tumour bleeding into bowel.
?GIST.
MACROSCOPIC DESCRIPTION: "Small bowel resection": A segment of small bowel 35mm in length x 20mm in diameter with a central exophytic mushrooming serosal tumour 48x42x35mm. Photograph taken. Tumour surface inked blue. Sectioning shows a pink fleshy tumour which extends into muscularis propria. No mucosal polyps or tumours are seen. No necrosis or haemorrhage is identified.
BLOCK DESIGNATION:
A - small bowel resection ends.
B-D - tumour including bowel wall.
E-F - tumour. P6. (TWR)
MICROSCOPIC DESCRIPTION: The sections show a circumscribed spindle cell tumour composed of intersecting fascicles. Tumour cells have medium sized oval nuclei, fine chromatin, small nucleoli and a moderate amount of fibrillary cytoplasm. There are occasional perinuclear vacuoles and frequent skenoid fibres. There are scattered dilated vessels. There are areas of granulation tissue, foamy macrophages and haemorrhage within the tumour. The overlying serosa appears haemorrhagic. The tumour replaces full thickness of the small bowel wall excluding the mucosa.
Focally there are ectatic vessels beneath the mucosa which focally communicate with the bowel lumen, consistent with a site of GI haemorrhage. The overlying mucosa is otherwise unremkarkable. The sections of margins are clear of tumour. No mitoses are identified.
By immunohistochemistry the tumour cells are C-KIT positive, DOG1 positive, SMA negative and S100 negative.
DIAGNOSIS: Small bowel resection:
* Gastro-intestinal stromal tumour (GIST)
- Size 48mm
- No mitoses
- C-KIT positive by immunohistochemistry
COMMENT: The behaviour of gastro-intestinal stromal tumours is difficult to predict. Based on the tumour location (small bowel), the size, and mitotic rate, this tumour is considered to have a low risk
of aggressive behaviour (REF: DIAGNOSIS OF GASTROINTESTINAL STROMAL TUMORS (Fletcher et al), HUMAN PATHOLOGY Volume 33, No. 5 (May 2002)).