Cytologists increasingly encounter atypical endocervical cells, becaus
e of the increasing incidence of endocervical adenocarcinoma and the u
se of improved endocervical sampling devices. These atypical endocervi
cal cells can cause diagnostic problems, especially in recognizing ade
nocarcinoma in situ (AIS) and distinguishing it from a variety of nonn
eoplastic changes. We analyzed 33 cervical smears from 22 patients wit
h confirmed AIS and compared these to 19 cervical smears from 17 patie
nts having atypical endocervical cells of undetermined significance an
d negative follow-up, including at least one tissue biopsy per case, t
o further investigate the cytologic features of AIS. The AIS smears ty
pically had crowded three-dimensional cellular aggregates, with marked
ly hyperchromatic nuclei having altered polarity. Frequently, a minor
component of AIS formed strips of distinctly columnar cells oi sheets.
Individual AIS cells occurred in 22 (67%) smears, but these were usua
lly inconspicuous. The AIS smears also had increased nuclear to cytopl
asmic ratios (100%), enlarged nuclei (94%), feathering (88%), rosettes
(85%), nucleoli (76%), apoptosis (73%), mitoses (64%), multiple nucle
oli (18%), and ciliated atypical cells (3%). Cytologic features occurr
ing significantly (P less than or equal to 0.001) more often in AIS ca
ses were a predominance of three-dimensional crowded aggregates (79% v
s. 32%), altered nuclear-polarity in most groups (88% vs. 16%), marked
hyperchromasia (91% vs. 16%), apoptosis (73% vs. 26%), an increased n
uclear to cytoplasmic ratio (100% vs. 63%), feathering (88% vs. 26%),
and individual atypical cells (67% vs. 16%). In summary, we identified
a number of architectural and cellular features that occur-red signif
icantly more often in AIS cases than in cases having atypical endocerv
ical cells of undetermined significance and negative follow-up. (C) 19
97 Wiley-Liss, Inc.