Gastrointestinal stromal tumour

Case contributed by Dr Jan Frank Gerstenmaier

Presentation

Upper GI bleeding.

Patient Data

Age: 55 years
Gender: Female
Photo

Endoscopy

There is blood in the jenunum. A submucosal mass was seen. More bleeding started after probing the mass. Clips were placed.

Jejunal bleeding vessel at endoscopy 42 x 37 x 31 mm mildly lobulated solid vividly enhancing/hypervascular mass in the right upper quadrant abuts the loop of jejunum marked by endoscopic clips, but may be centred over mesentery. Evidence of AV shunting into a prominent vein that drains into the portal venous system. The arterial supply appears to be from a jejunal branch. No evidence of active contrast extravasation/bleeding. No surrounding stranding. No 2nd lesion. No liver lesion. Minor basal atelectasis. Conclusion Mass lesion relating to the endoscopically marked jejunum is most probably a GIST tumor, although necrosis would be commonly seen for this size. Other hypervascular differentials include carcinoid or glomus tumours. The AV shunting may be related to the tumor, or be related to the clipping.

Pathology

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)).

Case Discussion

In a GIST of this size, the absence of necrosis at CT, and the extreme hypervascularity are unusual. Neither imaging nor histology can reliably predict a benign nature of the tumour. Please see comment at histology report.

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Case information

rID: 33588
Published: 15th Jul 2018
Last edited: 17th Jul 2018
Inclusion in quiz mode: Included

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