Fig. 9.13 The endometrioid (or "small cell") variant of endocervical adenocarcinoma in situ. (A) A hyperchromatic crowded grouping of very
densely packed small cells resembling endometrium. In (B), feathering is noted at the margins of the group and can be a clue to the correct interpretation.
(C) A pseudostratified strip of cells can be seen. Compared to similar architectural strips seen in Fig. 9.12, these cells are much smaller. (D) A smooth contoured
group of endometrioid AIS (conventional smear, Papanicolaou x HP).
Table 9.1 Classification of cervical adenocarcinoma
Typical endocervical type
Well-differentiated villoglandular papillary adenocarcinoma
(1) Adenoma malignum (minimal deviation adenocarcinoma)
(2) Intestinal type (including signet-ring cell and colloid adenocarcinoma
Minimal deviation adenocarcinoma
A f t e r Y o u n g a n d C le m e n t . 52
Three-dimensional groupings or syncytia can also be present
particularly when lesions exfoliate cells from higher in the
endocervical canal. Such cells have "exfoliative" features and
will "ball-up" into more dense, spherical shapes as they float in
the endocervical mucus. The typical architectural features of AIS,
including epithelial rosette formation, pseudostratified strips of
cells, and marginal feathering of cells in groups may be noted,
but these features will become ill-defined and more difficult to
recognize as lesions become more poorly differentiated. Nuclei
are enlarged (generally greater than 2-3 times the size of an inter-
mediate squamous cell nucleus) and pleomorphic, and show
irregular chromatin with areas of "clearing." Macronucleoli are
commonly evident. The cytoplasm is finely vacuolated to granu-
lar and may show columnar configuration. Again, in tumors of
poorer differentiation, the nuclear features will increase in their
atypicality. Mitoses and apoptotic bodies are commonly noted.
Individual tumor cells are present due to the discohesive nature
of these lesions. Tumor diathesis is generally present, indicative
of tumor and host necrosis and concurrent inflammatory reac-
tion (Fig. 9.20). However, in low-grade and minimally invasive
tumors, diathesis may be absent or minimal.