The heterogeneity of periodic acid-thionin schiff/KOH/PAS staining property and the histological grading of atypia in colorectal carcinoma and adenoma

Abstract

To assess the mucin changes associated with the development of colorectal cancer, the periodic acid-thionin schiff (PAT)/KOH/PAS staining properties of 38 advanced carcinomas, 8 submucosal invasive carcinoma, 29 mucosal carcinomas (adenomas with severe atypia), 19 adenomas with moderate atypia and 38 adenomas with mild atypia were studied with special attention to the heterogeneity of staining property within each lesion. 6 submucosal carcinomas and 28 mucosal carcinomas were judged to have benign adenomatous portion using hematoxilin-eosin staining. The more advanced the carcinomas, or the higher the grade of atypia of adenomas, the fewer the lesions of which goblet cell mucus (GCM) and the mucus at the luminal surface or that in the luminal accumulation (SC) stained red. SC frequently stained bluer than GCM in highly atypical glands. The staining properties of benign adenomatous portions concomitant with submucosal or mucosal carcinomas were similar to those of benign adenomas, but not to their carcinomatous foci. These findings suggest that the changes in the PAT/KOH/PAS staining property associated with the development of colorectal carcinoma mainly occur in SC, and that the majority of submucosal and mucosal carcinomas were `carcinoma in adenoma'.