Invasive breast carcinoma - IARC

A
B
Fig. 4.15 Simple hyperplasia. A The endometrial
glands vary from dilated to compact and are
bridged by a large squamous morule. B Note the
pseudostratified columnar epithelium with elongated
nuclei lacking atypia.
A
B
Fig. 4.16 Complex hyperplasia. A The endometrial glands show branching and budding. B There is glandular
crowding; however, cytological atypia is absent.
Rare types of endometrial carcinoma
Almost every type of carcinoma reported
elsewhere has been described in at least
a single case report as primary in the
endometrium.
Histopathology
These tumours are histologically (and
usually clinically, if enough cases are
available for analysis) identical to their
m o re common counterparts in other
organs. They include adenoid cystic carcinoma
{985}, glassy cell carc i n o m a
{1103} and mesonephric carc i n o m a
{2110}. Oncocytic/oxyphilic carcinoma is
thought by some to be a variant of clear
Fig. 4.17 Focal atypical hyperplasia. Atypical
hyperplasia is seen on the left and a cyclic
endometrium on the right.
cell carcinoma, whereas others consider
it to be a separate tumour.
Endometrial hyperplasia
Definition
A spectrum of morphologic alterations
ranging from benign changes, caused
by an abnormal hormonal environment,
to premalignant disease.
Criteria for histological typing
The endometrial hyperplasias are classified
by their degree of architectural complexity
as simple or complex (adenomatous)
and by their cytological (nuclear)
f e a t u res as hyperplasia or atypical
hyperplasia.
The endometrium is uniquely endowed
t h roughout the female re p roductive lifespan
with a complex regular cycle of periodic
proliferation, diff e rentiation, bre a k-
down and regeneration. This high cellular
t u rn o v e r, conditioned by ovarian hormones
and growth factors, has many
o p p o rtunities for losing its re g u l a t o ry cont
rols. Endometrial hyperplasia encompasses
conditions that range from benign
e s t rogen-dependent proliferations of
glands and stroma to monoclonal outg
rowths of genetically altered glands.
The high degree of morphological variability
of endometrial proliferations even
within the same sample is responsible for
the difficulty in defining consistent and
clinically meaningful diagnostic criteria
{240,3135}. A further complication is
fragmentation and scantiness of many
aspiration biopsies. Nevertheless, histological
interpretation remains the most
accessible, albeit somewhat subjective,
method of evaluating endometrial hyperplasias.
WHO classification
Many classifications had been proposed
prior to 1994 when the World Health
Organization (WHO) adopted its current
Table 4.02
World Health Organization classification of
endometrial hyperplasia {2602}.
Hyperplasias (typical)
Simple hyperplasia without atypia
Complex hyperplasia without atypia
(adenomatous without atypia)
Atypical hyperplasias
Simple atypical hyperplasia
Complex atypical hyperplasia
(adenomatous with atypia)
228 Tumours of the uterine corpus