BACKGROUND: Mismatch repair genes (such as MSH2, MLH1 and MSH6) mutations are present in over 80% of hereditary non-polyposis colorectal cancer (HNPCC) tumors, which frequently exhibit synchronous lesions. Sporadic colorectal cancer is rarely associated with synchronous lesions. AIM: To investigate the role of mismatch repair gene mutation in synchronous sporadic colorectal cancer. METHODS: Patients with sporadic synchronous colorectal adenocarcinomas were included in the study. Immunohistochemistry was performed using MSH2, MLH1 and MSH6 antibodies. RESULTS: All patients had two synchoronous lesions. None of them had altered MSH2 or MLH1 expression. One patient had altered MSH6 expression in both tumors. CONCLUSION: Possibly, other molecular mechanisms are involved in carcinogenesis of sporadic synchronous colorectal cancer.
Colorectal neoplasms; Immunohistochemistry, adenocarcinoma