Endometrial Lesions, Unusual Tumors, and Extrauterine Cancer
S '
Fig. 10.36 Clear cell carcinoma of the endometrium. LBC SurePath
Papanicolaou x HP. from a postmenopausal woman (same patient as that in
Fig. 10.31). Many neutrophils have accumulated in the cytoplasmic vacuoles.
dilatation or branching of the glands may lead to confusion with
hyperplastic processes. Not infrequently, metaplastic changes
are also common in the background of disordered proliferation.
Norimatsu has noted that the changes of eosinophilic and cili-
ated metaplasia can be identified with direct endometrial sam-
ples.80 Importantly, however, these authors noted that the features
of papillary syncytial metaplasia are difficult to distinguish from
hyperplastic processes. In papillary syncytial metaplasia, the
cells have abundant eosinophilic cytoplasm and rounded bland
nuclei. Cell clumps with projections of cytoplasm noted on the
surface are seen. These clumps are associated with condensed
stromal clusters and the bland nuclear morphology may aid in
making this diagnosis in contrast to the significant nuclear aty-
pia noted with serous carcinomas.
Endometrial Hyperplasia in Direct Endometrial
Direct endometrial sampling devices have had limited success
in the cytologic diagnosis of the precursors of endometrial
carcinoma, endometrial hyperplasia, and the precursor lesion
of type I endometrial adenocarcinoma.54,71,81-84 The cytologic
appearance of endometrial hyperplasia without cytologic atypia
overlaps considerably with that of proliferative endometrium
and regenerative endometrium, the latter of which frequently
occurs in the surface of endometrial polyps, with endometri-
tis, or with areas of repair.74 In simple endometrial hyperplasia
both endometrial stroma and epithelium are present in usual
amounts. The epithelial cells are columnar in shape, and show
moderately large ovoid nuclei. The nuclei are uniform through-
out, with finely granular chromatin. Small micronucleoli are evi-
dent (Figs 10.37 and 10.38). In addition, cytologic samples may
not reflect the overall histopathologic state of the endometrium.
The epithelial cells present in endometrial sampling may be
largely derived from superficial endometrial epithelium; such an
origin has little in common with the underlying deeper glandu-
lar epithelium.74 Consequently, there may be a lack of adequate
morphologic criteria in all samples for the recognition of these
endometrial hyperplasias.71
At the other end of the spectrum of hyperplasia, the cytologic
appearance of atypical hyperplasia resembles that of low-grade
Fig. 10.37 Simple endometrial hyperplasia. Direct endometrial
sampling (Papanicolaou x LP). Note the dilated and branching pattern of the
cellular fragment.
endometrioid adenocarcinomas. The glandular epithelium has
lost normal polarity, and is crowded and stratified (Figs 10.39
and 10.40). The nuclei are pleomorphic, and may show irregular
distribution of the chromatin. Nucleoli are often seen, and
may vary in size from small to medium. The epithelial cells are
enlarged, and show variable staining ranging from cyanophilic
to eosinophilic. Tissue necrosis is not a feature, and if seen,
should raise the possibility of adenocarcinoma.
For the above reasons, cytologic findings are usually com-
bined with architectural and histologic appearances of the
endometrium for a final cytodiagnosis. Even cytologic endome-
trial sampling systems emphasize the retention of architectural
features ("microbiopsies") so that interpretation of endome-
trial aspirates includes pattern-based criteria for histologic
Endometrial Carcinoma and Direct Endometrial
Although the cytologic detection of endometrial hyperplasia
has been disappointing, attempts to use endometrial aspirates
to detect endometrial carcinoma have been more successful. A
high degree of sensitivity for detecting endometrial carcinoma
has been reported in several series.71,81,85, 86 The cytodiagnosis
of carcinoma is based upon both architectural and cytologic
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