The present study uses morphometric
techniques to assess whether altered differentiation
patterns exist in PPM which might reflect its premalignant
status. Samples were obtained from resected
malignant lesions of large bowels of 10 Chinese patients.
Normal (N) samples were biopsied from the margins of
each resected large bowel. Potentially premalignant
(PPM) mucosae were obtained from within 2 cm of the
margins of the malignant lesions. Tissues were processed
for histological examination and using strict criteria,
colorectal crypts were divided into basal (B), intermediate
(I) and surface (S) segments. Interactive
digitisation of sections from each group was used to
generate the following morphometric parameters in each
segment: nuclear profile circularity indices (NSF and
NCI); nuclear numerical density (NA and Nv); the
degree of deviation of the major nuclear axis in relation
to the epithelial-connective junction (AGDMAX); cell
height (CH); the distance between nuclear apex to cell
apex (DNACA); the distance between cell base to
nuclear apex (DCBNA); stratification index (SI) - the
ratio of DCBNA and CH; and the volume density
of mucous vacuoles in the reference epithelium
(VVMV,EP)I.n comparisons of different segments within
groups, the nuclei at the S segment of N and PPM crypts
were more irregular and less circular in shape than
nuclei from other segments. There was a shift of nuclear
profile shape (NSF and NCI) from circular to ellipsiodal
between B and S segments. In comparisons of similar
segments between groups, no significant nuclear shape
changes were detected in nuclei of PPM crypts when
compared with nuclei in similar segments of N crypts
and the pattern of nuclear shape alterations resembled
those of normal crypts. In comparisons of different
segments within groups of N and PPM crypts,
AGDMAX. DNACA, DCBNA, CH and S1 parameters
demonstrated that epithelial cells at the I segments have
more centrally positioned nuclei with the tallest
Offprint requests to: Dr. George L. Tipoe, Department of Anatomy,
Faculty of Medicine, The University of Hong Kong, Li Shu Fan Building,
5 Sasson Road, Hong Kong
* In memoriam
epithelial height when compared with epithelial cells in
other segments of both crypts. In B segments, nuclear
NA and Nv were almost double those of other segments
in both N and PPM crypts, with marked reductions in
these parameters between B and I segments. VVMV,EP
was significantly highest in the I segment and
significantly lowest in the S segment of both groups.
Both N and PPM crypts showed similar trends in
VVMV,EP within the crypt segments but when
comparing similar segments between both crypts, a
significant difference was detected only between S
segments. The alterations of nuclear shape and packing
densities, orientation and mucous content in N crypts
were similarly expressed in PPM crypts and distinct
differences in numerical density (Nv) and stratification
index existed in crypts between these two groups when
comparing similar segments. All values in PPM were
consistently lower when compared with N crypts. These
preliminary observations may represent a subtly altered
state of cellular differentiation in PPM which may be a
reflection of early preneoplastic transformation