Brush cytology and biopsy in the diagnosis of colorectal cancer

OBJECTIVE: To determine the usefulness of brush cytology of colorectal lesions as compared to biopsy examination. STUDY DESIGN: One hundred brushing cytologies and biopsies were performed on patients who underwent colonoscopic examination for different symptoms. The cytologic smears were classified into five cytologic diagnostic categories. The histologic diagnoses were adenocarcinoma, adenoma and nonneoplastic lesion. RESULTS: Twenty-six cases were cytologically positive for malignant cells, and all were histologically diagnosed as adenocarcinoma. Nineteen cases were suspicious for malignancy on cytology; histologically, eight of them showed adenocarcinoma. Two other cases proved to be adenocarcinoma in subsequent biopsies. Nine cases were adenomas, with severe dysplasia in five of them. Fourteen cases that were cytologically negative with minimal glandular atypia showed seven adenomas and seven nonneoplastic lesions on biopsy. Forty cases negative for malignant cells showed 19 adenomas and 21 nonspecific changes in the biopsy examination. CONCLUSION: Colonoscopic brushing cytodiagnosis is a sensitive technique for the detection of colorectal cancer. The combination of brushing cytology and biopsy improves the accuracy of diagnosis.