title: [pT1 cancer of the rectum and sigmoid without signs of adenomatous background].
abstract: On the basis of analysis of the histological structure of 1,095 polypoid and nonpolypoid tumors, the frequency of detection of "primary" carcinoma and its clinical and histological features were studied. It is shown that one third of pTI category carcinomas are devoid of signs of a preceding adenoma. Polypoid primary carcinomas account for only 15.8% of cases. The prevailing plaque-like, flat, and ulcerated tumors invade the submucous layer more frequently than malignancy adenomas of the corresponding size and produce metastases to the lymph nodes more frequently. The tumor develops against the background of precancerous and dysplastic changes in the epithelium in the nonpolypoid mucosa and in the adenomas. The indications for economical operations in primary carcinoma, in distinct from those in malignancy adenomas, should be determined with caution.
authors.forename: T A
authors.initials: TA
authors.lastname: Belous
authors.forename: G A
authors.initials: GA
authors.lastname: Frank
authors.forename: V I
authors.initials: VI
authors.lastname: Chissov
authors.forename: A M
authors.initials: AM
authors.lastname: Averbakh
authors.forename: S N
authors.initials: SN
authors.lastname: Kazanova
mesh_terms: D012809:Colon, Sigmoid / Q000473:pathology; D006801:Humans; D007417:Intestinal Polyps / Q000473:pathology* / Q000601:surgery; D011230:Precancerous Conditions / Q000473:pathology* / Q000601:surgery; D012004:Rectal Neoplasms / Q000473:pathology* / Q000601:surgery; D012007:Rectum / Q000473:pathology; D012811:Sigmoid Neoplasms / Q000473:pathology* / Q000601:surgery
vernacular_title: Rak priamoĭ i sigmovidnoĭ kishok PT1 bez priznakov adenomatoznogo fona.