[Standardization of the cytological conclusions in adenomas and cancer of the rectum].

The histological patterns of 120 adenomas and 365 carcinomas of the rectum were established cytologically in accordance with the WHO Histological Classification of Tumours on the basis of morphological, cellular and functional characteristics of neoplasm differentiation. It was found that cytological methods cannot be fully relied upon in the identification of the histological pattern of adenoma. Three degrees of adenoma cell atypia are distinguished: mild, moderate and severe. The latter is more characteristic of villous tumor. The following cytological classification of rectal cancer is suggested: 1. Adenocarcinoma: (a) well-differentiated, (b) moderately-differentiated. 2. Mucinous adenocarcinoma. 3. Signet-ring cell carcinoma. 4. Squamous cell carcinoma: (a) keratinizing, (b) non-keratinizing. 5. Undifferentiated cell carcinoma. 6. Carcinoma (histologically unidentifiable).