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. CD 117 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 e-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.
|Titolo:||Immunohistochemical profile and c-kit mutations in gastrointestinal stromal tumors|
|Autori interni:||COGGI, GUIDO (Penultimo)|
ROMAGNOLI, SOLANGE (Primo)
BOSARI, SILVANO (Ultimo)
|Parole Chiave:||c-kit mutation; CD117; CD34; GIST; Sarcoma|
|Settore Scientifico Disciplinare:||Settore MED/08 - Anatomia Patologica|
|Data di pubblicazione:||2005|
|Digital Object Identifier (DOI):||10.1016/j.prp.2005.01.005|
|Appare nelle tipologie:||01 - Articolo su periodico|
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