AIM: To identify the gastrointestinal stromal tumors(GISTs) that are negative for CD117 expression by immunohistochemistry and to characterize their malignant potential.METHODS: A total of 108 primary mesenchymal tumo...AIM: To identify the gastrointestinal stromal tumors(GISTs) that are negative for CD117 expression by immunohistochemistry and to characterize their malignant potential.METHODS: A total of 108 primary mesenchymal tumors of the gastrointestinal tract were screened to select CD117-negative tumors, from which KIT(exons 9, 11, 13, and 17)and PDGFRA (exons 10, 12, 14, and 18) were sequenced to identify GISTs. Tumor recurrence and distant metastasis were used as the criteria of malignancy.RESULTS: The result showed that approximately 25%(29/108) of the gastrointestinal mesenchymal tumors were negative for CD117 and approximately 6% (7/108)of the tumors were CD117-negative GISTs. All these CD117-negative tumors had a mutated KITand a wildtype PDGFRA. All CD117-negative GISTs with mutations at codons 557/558 of KIThad mitotic counts ＞10/50 high power field, and 75% (3/4) of them showed multiple recurrence or distant metastasis.CONCLUSION: CD1 17-negative KITmutated GISTs account for approximately 6% of the gastrointestinal mesenchymal tumors. Tumor recurrence or distant metastasis correlates to both theKITmutations at codons 557/558 and the mitotic counts, but not to the tumor size.展开更多
Epithelioid gastrointesinal tumors (GISTs) are less likely to have c-kit gene mutations (and express CD117) than spindle cell GISTs. CD117 negative/c-kit negative GISTs can have platelet-derived growth factor alpha (P...Epithelioid gastrointesinal tumors (GISTs) are less likely to have c-kit gene mutations (and express CD117) than spindle cell GISTs. CD117 negative/c-kit negative GISTs can have platelet-derived growth factor alpha (PDGFRα) gene mutations, overexpress PDGFRα protein and respond to imatinib mesylate. Many cases of CD117-negative/CD117-weakly positive, c-kit mutation negative and PDGFRα mutation positive myxoid epithelioid GISTs and one case of CD117-positive GIST with chondro-myxoid features mimicking chondrosarcoma have been reported. We report a case of myxoid epithelioid GIST with predominance of chondroid and chordoid areas resembling an extraskeletal myxoid chondrosarcoma that was strongly positive for CD117, PDGFRα and DOG1 (Discovered on GIST 1) by immunohistochemistry, but lacked c-kit and PDGFRα gene mutations. It is possible that CD117 is strongly positive if a myxoid epithelioid GIST has chondroid/chordoid appearance, but a larger study is needed to confirm this association. CD117 expression in GISTs is important, because GISTs showing CD117 positivity respond to imatinib. No comment can be made about the prognostic significance of chondroid/chordoid appearance in the GISTs.展开更多
Objective:The aim of the study was to review the clinical records of 122 patients with gastrointestinal stromal tumors(GISTs) and analyze their clinicopathologic and immunohistochemical characteristics.Methods:The med...Objective:The aim of the study was to review the clinical records of 122 patients with gastrointestinal stromal tumors(GISTs) and analyze their clinicopathologic and immunohistochemical characteristics.Methods:The medic records of 122 patients with GISTs during the periods from January 2002 to May 2010 were reviewed.All tumors were confirmed by histological and immunohistochemical analyses.Results:The tumors occurred in 59 males and 63 females,ranging from 25 to 77 years.Of all cases,46 cases originated from stomach,42 from small intestine,17 from colon and rectum and 9 from retroperitoneal cavity and 4 cases from extra-gastrointestinal site.Liver was the most common organ that tumors metastases involved.Immunohistochemically,there were 114 tumors being positive for CD117 while 8 tumors negative for it.The frequencies of CD34 positive were higher in the stomach and rectum(89.1% and 86.7% respectively) than in the small intestine(64.3%,P < 0.05).Higher expression of SMA was in the tumors located in small intestine(54.8%) while the expressions of SMA in the gastric and rectal tumors were relatively low(21.7% and 20.0% respectively,P < 0.05).Conclusion:Gastrointestinal stromal tumors can occur in the gastrointestinal tract as well as in the extra-gastrointestinal sites.The frequencies of CD34 and SMA expression vary significantly with different locations.展开更多
文摘AIM: To identify the gastrointestinal stromal tumors(GISTs) that are negative for CD117 expression by immunohistochemistry and to characterize their malignant potential.METHODS: A total of 108 primary mesenchymal tumors of the gastrointestinal tract were screened to select CD117-negative tumors, from which KIT(exons 9, 11, 13, and 17)and PDGFRA (exons 10, 12, 14, and 18) were sequenced to identify GISTs. Tumor recurrence and distant metastasis were used as the criteria of malignancy.RESULTS: The result showed that approximately 25%(29/108) of the gastrointestinal mesenchymal tumors were negative for CD117 and approximately 6% (7/108)of the tumors were CD117-negative GISTs. All these CD117-negative tumors had a mutated KITand a wildtype PDGFRA. All CD117-negative GISTs with mutations at codons 557/558 of KIThad mitotic counts ＞10/50 high power field, and 75% (3/4) of them showed multiple recurrence or distant metastasis.CONCLUSION: CD1 17-negative KITmutated GISTs account for approximately 6% of the gastrointestinal mesenchymal tumors. Tumor recurrence or distant metastasis correlates to both theKITmutations at codons 557/558 and the mitotic counts, but not to the tumor size.
文摘Epithelioid gastrointesinal tumors (GISTs) are less likely to have c-kit gene mutations (and express CD117) than spindle cell GISTs. CD117 negative/c-kit negative GISTs can have platelet-derived growth factor alpha (PDGFRα) gene mutations, overexpress PDGFRα protein and respond to imatinib mesylate. Many cases of CD117-negative/CD117-weakly positive, c-kit mutation negative and PDGFRα mutation positive myxoid epithelioid GISTs and one case of CD117-positive GIST with chondro-myxoid features mimicking chondrosarcoma have been reported. We report a case of myxoid epithelioid GIST with predominance of chondroid and chordoid areas resembling an extraskeletal myxoid chondrosarcoma that was strongly positive for CD117, PDGFRα and DOG1 (Discovered on GIST 1) by immunohistochemistry, but lacked c-kit and PDGFRα gene mutations. It is possible that CD117 is strongly positive if a myxoid epithelioid GIST has chondroid/chordoid appearance, but a larger study is needed to confirm this association. CD117 expression in GISTs is important, because GISTs showing CD117 positivity respond to imatinib. No comment can be made about the prognostic significance of chondroid/chordoid appearance in the GISTs.
文摘Objective:The aim of the study was to review the clinical records of 122 patients with gastrointestinal stromal tumors(GISTs) and analyze their clinicopathologic and immunohistochemical characteristics.Methods:The medic records of 122 patients with GISTs during the periods from January 2002 to May 2010 were reviewed.All tumors were confirmed by histological and immunohistochemical analyses.Results:The tumors occurred in 59 males and 63 females,ranging from 25 to 77 years.Of all cases,46 cases originated from stomach,42 from small intestine,17 from colon and rectum and 9 from retroperitoneal cavity and 4 cases from extra-gastrointestinal site.Liver was the most common organ that tumors metastases involved.Immunohistochemically,there were 114 tumors being positive for CD117 while 8 tumors negative for it.The frequencies of CD34 positive were higher in the stomach and rectum(89.1% and 86.7% respectively) than in the small intestine(64.3%,P < 0.05).Higher expression of SMA was in the tumors located in small intestine(54.8%) while the expressions of SMA in the gastric and rectal tumors were relatively low(21.7% and 20.0% respectively,P < 0.05).Conclusion:Gastrointestinal stromal tumors can occur in the gastrointestinal tract as well as in the extra-gastrointestinal sites.The frequencies of CD34 and SMA expression vary significantly with different locations.
