Eble JN, Sauter G., Epstein JI, Sesterhenn IA - iarc

A
Fig. 3.12 A Organ-confined adenocarcinoma of the prostate extending to edge of gland.
B Adenocarcinoma of the prostate with focal extra-prostatic extension.
B
Fig. 3.15 Extraprostatic extension by prostatic adenocarcinoma,
with tracking along nerve, into
periprostatic adipose tissue.
cases of obvious carcinoma, there may
be cells that closely mimic basal cells.
These cells when labeled with basal cell
specific antibodies are negative and represent
fibroblasts closely apposed to the
neoplastic glands. Conversely, basal
cells may not be readily recognized in
benign glands without the use of special
studies. The histopathology of prostatic
cancer, and its distinction from benign
glands, rests on a constellation of architectural,
nuclear, cytoplasmic, and intraluminal
features. With the exception of
three malignant specific features listed at
the end of this section, all of the features
listed below, while more commonly seen
in cancer, can also be seen in benign
mimickers of cancer.
A
Fig. 3.13 A Intraprostatic lymphovascular space invasion by prostatic adenocarcinoma. B Ejaculatory duct
invasion by prostatic adenocarcinoma, with duct wall invasion, with sparing of ejaculatory duct epithelium
and lumen.
Fig. 3.14 Limited adenocarcinoma of the prostate on needle biopsy.
tinguish them from benign prostatic
glands, to poorly differentiated tumours,
difficult to identify as being of prostatic
origin. A feature common to virtually all
prostate cancers is the presence of only
a single cell type without a basal cell
layer. Benign prostate glands, in contrast,
contain a basal cell layer beneath
the secretory cells. The recognition of
basal cells on hematoxylin and eosin
stained sections is not straightforward. In
B
Architectural features
Benign prostatic glands tend to grow
either as circumscribed nodules within
benign prostatic hyperplasia, radiate in
columns out from the urethra in a linear
fashion, or are evenly dispersed in the
peripheral zone {1685}. In contrast,
gland-forming prostate cancers typically
contain glands that are more crowded
than in benign prostatic tissue, although
there is overlap with certain benign mimickers
of prostate cancer. Glands of adenocarcinoma
of the prostate typically
grow in a haphazard fashion. Glands oriented
perpendicular to each other and
glands irregularly separated by bundles
of smooth muscle are indicative of an
infiltrative process. Another pattern characteristic
of an infiltrative process is the
presence of small atypical glands situated
in between larger benign glands. With
the loss of glandular differentiation and
the formation of cribriform structures,
fused glands, and poorly formed glands,
the distinction between benign glands
based on the architectural pattern
becomes more apparent. Tumours composed
of solid sheets, cords of cells, or
isolated individual cells characterize
undifferentiated prostate cancer. These
architectural patterns are key components
to the grading of prostate cancer
(see Gleason grading system).
170 Tumours of the prostate