THE CLINICAL-SIGNIFICANCE OF THE HISTOLOGIC SUBCLASSIFICATION OF COLORECTAL-CARCINOMA

According to the histologic features at the deepest level of tumor inv asion (the tumor apex), we classified colorectal carcinomas as follows : well differentiated (W), moderately differentiated (M), and mucinous (Muc). By assessing its glandular configuration and cellular arrangem ent, the M type was further subdivided in to two different groups: mod erately well differentiated (Mw) and moderately poorly differentiated (Mp) carcinomas. In our sample there were 56 W, 53 Mw, 20 Mp and 13 Mu c tumors. The malignant potential of each tumor was evaluated by exami ning for the presence or absence of lymphatic invasion, venous invasio n, lymph node metastases and liver metastases. In comparison with the other tumors, the Mp tumors proved to harbor the highest malignant pot ential, exhibiting a higher incidence of lymphatic invasion (95%, 19/2 0 of the cases), venous invasion (75%, 15/20 of the cases), lymph node metastases (80%, 16/20 of the cases), and liver metastases (40%, 8/20 of the cases). Colorectal carcinomas are composed of multiple cell po pulations with different biological and malignant properties, and thro ugh the histologic subclassification we could identify that Mp tumors have the highest potential to invade normal tissue and metastasize.