MULTIPLE SYNCHRONOUS COLORECTAL CARCINOMAS - A PLOIDY STUDY BY IMAGE-ANALYSIS

Cytometry could represent an ancillary technique to morphology in orde r to understand whether multiple synchronous colorectal carcinomas aro se independently. Twenty-eight multiple synchronous tumours, assessed by means of a computerized image analysis system for DNA ploidy, were categorized as diploid (4) or not diploid (24). The ploidy classes wer e: DNA-diploid, DNA-tetraploid, and DNA-aneuploid. The DNA Index (DI) ranged from 0,90 to 2,66. The overall concordance rate for ploidy and DI class with synchronous tumours was 69% and 31%, respectively. The h igh concordance rate in ploidic categories suggests the metastatic ori gin of our multiple synchronous tumours. Moreover, they showed site, D ukes' classification, degree of differentiation, percentage of ploidy class, and DI distribution comparable to the single colorectal carcino mas. In conclusion, image analysis is a reliable technique to determin e the independent clonality or the common origin of multiple colorecta l tumours when the evaluation based on the simple histopathological cr iteria is not satisfactory.