Gastrointestinal stromal tumour: Difference between revisions

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==General==
==General==
Epi.
===Epidemiology===
*arises from ''Interstitial cells of Cajal''<ref name=pmid17090188>{{cite journal |author=Miettinen M, Lasota J |title=Gastrointestinal stromal tumors: review on morphology, molecular pathology, prognosis, and differential diagnosis |journal=Arch. Pathol. Lab. Med. |volume=130 |issue=10 |pages=1466–78 |year=2006 |month=October |pmid=17090188 |doi= |url=http://journals.allenpress.com/jrnlserv/?request=get-abstract&issn=0003-9985&volume=130&page=1466}}</ref>
*arises from ''Interstitial cells of Cajal''<ref name=pmid17090188>{{cite journal |author=Miettinen M, Lasota J |title=Gastrointestinal stromal tumors: review on morphology, molecular pathology, prognosis, and differential diagnosis |journal=Arch. Pathol. Lab. Med. |volume=130 |issue=10 |pages=1466–78 |year=2006 |month=October |pmid=17090188 |doi= |url=http://journals.allenpress.com/jrnlserv/?request=get-abstract&issn=0003-9985&volume=130&page=1466}}</ref>
*Classically splits the layers of the ''muscularis propria'' - as this is where the ''interstitial cells of Cajal'' are located.<ref name=pmid16402273>{{cite journal |author=Agaimy A, Wünsch PH |title=Gastrointestinal stromal tumours: a regular origin in the muscularis propria, but an extremely diverse gross presentation. A review of 200 cases to critically re-evaluate the concept of so-called extra-gastrointestinal stromal tumours |journal=Langenbecks Arch Surg |volume=391 |issue=4 |pages=322–9 |year=2006 |month=August |pmid=16402273 |doi=10.1007/s00423-005-0005-5 |url=}}</ref>
*Classically splits the layers of the ''muscularis propria'' - as this is where the ''interstitial cells of Cajal'' are located.<ref name=pmid16402273>{{cite journal |author=Agaimy A, Wünsch PH |title=Gastrointestinal stromal tumours: a regular origin in the muscularis propria, but an extremely diverse gross presentation. A review of 200 cases to critically re-evaluate the concept of so-called extra-gastrointestinal stromal tumours |journal=Langenbecks Arch Surg |volume=391 |issue=4 |pages=322–9 |year=2006 |month=August |pmid=16402273 |doi=10.1007/s00423-005-0005-5 |url=}}</ref>


Factors predictive of malignant behaviour<ref name=pmid17090188/>
===Factors predictive of malignant behaviour===
Features suggesting a bad prognosis:<ref name=pmid17090188/>
*Large size.
*Large size.
**Often benign if small size.
**Often benign if small size.
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==See also==
==See also==
*[[Stomach]]
*[[Stomach]].
*[[Small bowel]]
*[[Small bowel]].
*[[Gastrointestinal pathology]]
*[[Gastrointestinal pathology]].


==References==
==References==

Revision as of 19:29, 13 May 2010

The gastrointestinal stromal tumour, abbreviated GIST, is uncommon tumour of the GI tract.

General

Epidemiology

  • arises from Interstitial cells of Cajal[1]
  • Classically splits the layers of the muscularis propria - as this is where the interstitial cells of Cajal are located.[2]

Factors predictive of malignant behaviour

Features suggesting a bad prognosis:[1]

  • Large size.
    • Often benign if small size.
  • High mitotic rate (for area 5mm^2).
  • Site - small intestine GISTs worse than stomach GISTs.

Small intestine bad prognosis:[1]

  • >5 mitoses/5 mm^2 or size >10 cm.

Stomach bad prognosis:[1]

  • >5 mitoses/5 mm^2 and size >5 cm.

Location

Most common locations in order:[1]

  • 60% in stomach.
  • 35% in small intestine.
  • 5% elsewhere.

Small intestinal GISTs have a worse prognosis than gastric ones.[1]

Definition

  • Mutation in the Kit gene or PDGFRA (Platelet-derived growth factor receptor, alpha polypeptide) gene.[1]

Micro.

  • Classically, spindle cell morphology; however, may be epithelioid (round).
  • +/-Cytoplasmic inclusions.[3]

IHC

  • CD34+ in 70%.[1]
  • CD117+ in 95%.[1]
    • Mast cells are the internal positive control.
  • Desmin+ in 5%.[1]

ICH Work-up panel

  • S-100 (neural tumours, rarely +ve in GISTs[1]).
  • CD34, CD117 (GIST).
  • Desmin (muscle tumours).

DDx

  • Leiomyosarcoma.
  • Leiomyoma.
  • Neural tumours.
    • Neurofibroma.
    • Schwannoma (GFAP+ --uniformly neg. in GISTs).[1]

Special tests

  • Sequence Kit gene, PDGFRA gene.
    • Kit gene sequencing is being done more frequently as of late-- if a mutation is found it suggest the drug imatinib will be effective.

Treatment

See also

References

  1. ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 Miettinen M, Lasota J (October 2006). "Gastrointestinal stromal tumors: review on morphology, molecular pathology, prognosis, and differential diagnosis". Arch. Pathol. Lab. Med. 130 (10): 1466–78. PMID 17090188. http://journals.allenpress.com/jrnlserv/?request=get-abstract&issn=0003-9985&volume=130&page=1466.
  2. ↑ Agaimy A, Wünsch PH (August 2006). "Gastrointestinal stromal tumours: a regular origin in the muscularis propria, but an extremely diverse gross presentation. A review of 200 cases to critically re-evaluate the concept of so-called extra-gastrointestinal stromal tumours". Langenbecks Arch Surg 391 (4): 322–9. doi:10.1007/s00423-005-0005-5. PMID 16402273.
  3. ↑ PMID 775795