Distribution of tissue polypeptide antigen (TPA) in normal mucosa, in colitis ulcerosa, in adenomas and in carcinomas of the human colorectum. An immunohistochemical study.

65 carcinomas with their normal resection margins, 30 adenomas of the colorectum, and also ulcerative colitis biopsies from 10 cases were analysed immunohistochemically for pattern and intensity of expression of Tissue Polypeptide Antigen (TPA). In normal colon, and in well- and moderately-differentiated carcinomas, a cell membrane type staining pattern was predominant. In ulcerative colitis, in carcinoma cell groups within mucus of mucinous carcinomas or in single cells at the invasion front of all grades of carcinomas, a strong cytoplasmic type staining pattern was found. The cytoplasmic pattern was also found in poorly differentiated carcinomas, but with weaker staining intensity. The relationship between staining intensity and pattern and carcinoma grade was significant, whereas a similar relationship with the Dukes stages was not significant.