TY - JOUR
T1 - p53 and K-ras mutational genotyping in pulmonary carcinosarcoma, spindle cell carcinoma, and pulmonary blastoma
T2 - Implications for histogenesis
AU - Holst, Valerie A.
AU - Finkelstein, Sydney
AU - Colby, Thomas V.
AU - Myers, Jeffrey L.
AU - Yousem, Samuel A.
PY - 1997
Y1 - 1997
N2 - In an attempt to understand the molecular pathogenesis of biphasic pulmonary neoplasms, the authors studied 25 cases of carcinosarcoma, spindle cell carcinoma, and pulmonary blastoma using a combined immunohistochemical and topographic genotyping approach for the presence of p53 abnormalities within the different epithelial and mesenchymal components of these tumors. Genotyping involved a search for point mutational damage in p53 exons 5-8, which was correlated with p53 immunoreactivity. This analytical approach demonstrated p53 missense point mutations in four of nine cases of spindle cell carcinoma with a 100% concordance rate between p53 immunopositivity and the presence of DNA mutational damage. One of six carcinosarcomas, heterologous in type, exhibited a p53 mutation. The concordance rate among carcinosarcomas was also 100%. However, the concordance rate among classic biphasic pulmonary blastomas was only 43%, with one of seven cases demonstrating a p53 mutation by DNA genotyping. The lack of concordance in pulmonary blastomas was possibly due to the existence of genotypically distinct subsets of tumor cells likely bearing mutations among largely nonmutated cells. In a similar fashion, among three well-differentiated fetal type adenocarcinomas, no p53 mutations were detected despite the presence of focal p53 immunopositivity in one of the cases. No K-ras mutations were detected in any of the 25 tumors examined. Monoclonal histogenesis from a single totipotential cell in a subset of these neoplasms (six of 22 cases) was supported by the finding of p53 overexpression and identical p53 mutational genotype in both the epithelial and spindle elements of the tumors. Furthermore, the finding of a small percentage of p53 positive tumor cells within one or both components suggests late acquisition of p53 mutational change in a subset of pulmonary blastomas.
AB - In an attempt to understand the molecular pathogenesis of biphasic pulmonary neoplasms, the authors studied 25 cases of carcinosarcoma, spindle cell carcinoma, and pulmonary blastoma using a combined immunohistochemical and topographic genotyping approach for the presence of p53 abnormalities within the different epithelial and mesenchymal components of these tumors. Genotyping involved a search for point mutational damage in p53 exons 5-8, which was correlated with p53 immunoreactivity. This analytical approach demonstrated p53 missense point mutations in four of nine cases of spindle cell carcinoma with a 100% concordance rate between p53 immunopositivity and the presence of DNA mutational damage. One of six carcinosarcomas, heterologous in type, exhibited a p53 mutation. The concordance rate among carcinosarcomas was also 100%. However, the concordance rate among classic biphasic pulmonary blastomas was only 43%, with one of seven cases demonstrating a p53 mutation by DNA genotyping. The lack of concordance in pulmonary blastomas was possibly due to the existence of genotypically distinct subsets of tumor cells likely bearing mutations among largely nonmutated cells. In a similar fashion, among three well-differentiated fetal type adenocarcinomas, no p53 mutations were detected despite the presence of focal p53 immunopositivity in one of the cases. No K-ras mutations were detected in any of the 25 tumors examined. Monoclonal histogenesis from a single totipotential cell in a subset of these neoplasms (six of 22 cases) was supported by the finding of p53 overexpression and identical p53 mutational genotype in both the epithelial and spindle elements of the tumors. Furthermore, the finding of a small percentage of p53 positive tumor cells within one or both components suggests late acquisition of p53 mutational change in a subset of pulmonary blastomas.
KW - Carcinosarcoma
KW - Genotyping
KW - Immunohistochemistry
KW - K-ras oncogene
KW - Lung
KW - Pulmonary blastoma
KW - Sarcomatoid carcinoma
KW - Spindle cell carcinoma
KW - Squamous cell carcinoma
KW - Well-differentiated fetal type adenocarcinoma
KW - p53 oncogene
UR - http://www.scopus.com/inward/record.url?scp=0030883154&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0030883154&partnerID=8YFLogxK
U2 - 10.1097/00000478-199707000-00008
DO - 10.1097/00000478-199707000-00008
M3 - Article
C2 - 9236836
AN - SCOPUS:0030883154
SN - 0147-5185
VL - 21
SP - 801
EP - 811
JO - American Journal of Surgical Pathology
JF - American Journal of Surgical Pathology
IS - 7
ER -