NUCLEAR AND CELLULAR MORPHOMETRY OF NORMAL AND POTENTIALLY PREMALIGNANT EPITHELIUM DURING EPITHELIAL CELLULAR-DIFFERENTIATION AND MATURATION IN HUMAN LARGE-BOWEL CRYPTS

This study investigates whether variations of nuclei and cells exist d uring differentiation of normal (N) and potentially premalignant (PPM) epithelia of the human large bowel using morphometric techniques. Sam ples were obtained from resected large bowels with malignant lesions o f 10 Chinese patients. N samples were biopsied from the margins of eac h resected large bowel. PPM samples were obtained within 2 cm of the m argins of the malignant lesions. Tissues were processed for routine hi stology under strictly standardised schedules and 4 mu m serial sectio ns were stained with H&E. Crypts were divided into basal(B), intermedi ate (I) and surface (S) segments using strict criteria. Interactive di gitisation was performed using a Zeiss VIDAS image analyser and morpho metric parameters quantified comprised nucleo-cytoplasmic (N/C) ratio and nuclear (V-N), cytoplasmic (V-CYT) and cellular (V-CELL) volumes, major (a) and minor (b) axes, nuclear axial (a/b) ratio, nuclear area (AN), nuclear perimeter (PERIM) and nuclear diameter (D). The largest nuclei (A(N), D, V-N) were observed in S segments and differed signifi cantly from the nuclei of the other two segments of N and PPM crypts. Nuclear size of PPM crypts in all segments was significantly smaller t han the nuclei of corresponding segments of N crypts. Data for PERIM a nd a/b ratio suggested that the nuclei at the surface segment of N and PPM crypts were less circular in shape and had longer boundaries than nuclei from other segments. Nuclear volumetric variations and the shi ft of nuclear profile shape from circular to ellipsiodal between B and S segments might reflect an increase in functional and metabolic requ irements of the actively dividing and differentiating cells at the B a nd I segments of the N and PPM crypts. The patterns of change in N cry pts were similarly expressed in PPM crypts and distinct differences ex isted in crypts between these two groups when comparing similar segmen ts. All values in PPM were consistently lower when compared with N cry pts. These initial observations may represent a subtle altered state o f cellular differentiation in PPM which may be a reflection of early p reneoplastic transformation.