[Small-cell rectal carcinoma coexisted with tubular-villous adenoma].

The paper describes a case of small-cell high-grade endocrine carcinoma of the rectum concurrent with tubular-villous adenoma in a 58 year-old woman. All epithelial cells of adenoma have been ascertained to be "mixed" exoendocrine endocrinocytes (secrete mucus and contain neuroendocrine granules), contain progesterone receptors, and express CK 8, 18, and 19. Some high-grade neuroendocrine carcinoma cells also secrete mucus. The presence of mitotic activity (Ki-67, 35%), high p53 protein expression (more than 50%), marked CK 18 expression, and clinical data confirm high malignancy of this histological type of the tumor.