TISSUE-CEA IN COLORECTAL CARCINOMAS - AN IMMUNOHISTOCHEMICAL STUDY

We carried out a CEA immunohistochemical study on 80 colorectal carcin omas, using the PAP methodology. Also we studied peritumoral <<normal> > mucosa on 69 cases. All tumoral (80/80) and the major part of normal colonic mucosa (68/69) cases stained positively. We present our exper ience with this immunohistochemical staining using a qualitative semiq uantitative evaluation, as an easy and reliable procedure. This permit s to obtain, by immunostaining, a better homogeneous group of tumours (Apical, Mixed and Cytoplasmic, or Weak and Strong), necessary to furt her correlation with various tumoral parameters. On the basis of this evaluation, we found: A staining of weak intensity (65/68) of Apical t ype (55/68) in the vast majority of the normal, peritumoral mucosa. In tumors we found a prevalence of strong intensity (67/80), in relation to its major content of CEA. With respect to the type of immunostaini ng, although Apical staining (32/80) exists the Cytoplasmic (34/80) is predominant together with the Myxed type (14/80). This is expression of the alterations in secretion and distribution of the tissue CEA. We analyze the difficulties of such classification caused by the tumoral heterogeneity and we include other data whose significance is not alw ays clear.