Immunohistochemical profile and c-kit mutations in gastrointestinal stromal tumors.
Pathol Res Pract
; 201(2): 71-81, 2005.
Article
em En
| MEDLINE
| ID: mdl-15901127
ABSTRACT
Gastrointestinal stromal tumors (GISTs) are low-grade sarcomas arising from the interstitial cells of Cajal, harboring mutation of c-kit. We investigated the morphological, immunohistochemical, and molecular profile of 55 GISTs to establish the prevalence of mutations, their clinical significance, and diagnostic utility. c-kit mutations were investigated by evaluating the entire coding sequence of the gene with non-radioisotopic PCR-SSCP, and characterized with fluorescent cycle sequencing. Mutations were detected in 39 tumors (71%), the majority (67%) involving exon 11. Two tumors showed exon 9 mutations (one tumor located in the small intestine and one in the stomach), whereas two cases showed a polymorphism at the splicing site of exon/intron 1 present in healthy blood donors with a 3% frequency. CD117 was expressed in 53 tumors (96%); CD34 was positive in 42 cases (76%); 42 cases (76%) expressed both CD117 and CD34. c-kit mutations were similarly distributed in stromal tumors at low risk of aggressive behavior (78%), intermediate risk (66%), and high risk (71%). Fifteen tumors expressing CD117 showed wild-type kit gene, and on histological grounds, they were equally distributed among epithelioid and spindle cell morphology. One case neither expressed CD117 nor did it show c-kit mutation. Data suggest that both immunohistochemical and molecular evaluation may be useful in tumors likely to be classified as GISTs; molecular analysis appears valuable to support the diagnosis and to identify cases that can benefit from recent novel therapeutic tools.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas Proto-Oncogênicas c-kit
/
Antígenos CD34
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Tumores do Estroma Gastrointestinal
Tipo de estudo:
Prognostic_studies
/
Risk_factors_studies
Limite:
Adolescent
/
Adult
/
Aged
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Aged80
/
Female
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Humans
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Male
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Middle aged
Idioma:
En
Revista:
Pathol Res Pract
Ano de publicação:
2005
Tipo de documento:
Article