8
Benign Proliferative Reactions, Intraepithelial Neoplasia, and Invasive cancer of the Uterine cervix
Fig. 8.85 Carcinoma
in situ.
Syncytial aggregate of cells. Nuclei vary in size
and shape and frequently overlap. Nuclear chromatin is irregularly distributed
and coarsely granular (Papanicolaou x OI).
the relatively higher differentiation (maturation) of the dysplas-
tic epithelium, in comparison with the epithelium composing
the carcinoma in situ.
Cell Size and Shape.
Cells from a carcinoma in situ lesion are
relatively small compared with cells from normal stratified
squamous epithelium or dysplastic cells. Cells from the histo-
logically large-cell variant of carcinoma in situ are predomi-
nantly in the range of small immature squamous metaplastic
cells. Similarly, cells from a histologically small-type carcinoma
in situ are in the range of reserve cells. From a series of cytologic
specimens in cases of histologically proven carcinomas in situ,
Patten computed a mean cell area of 238 pm2.12 The cells are
predominantly round to oval, reflecting their immature char-
acter. Irregular or elongated cell forms are related to a specific
superficial change of the lesion. The sparse cytoplasm stains
predominantly basophilic, a cytoplasmic staining reaction that
reflects the lack of keratinization in these undifferentiated cells.
The few cells showing an eosinophilic staining reaction are most
likely derived from a coexisting dysplasia. Owing to the highly
vulnerable cytoplasm in cases of carcinoma in situ, the finding
of cells with damaged cytoplasm or with bare nuclei is frequent
(Fig. 8.86).
Fig. 8.86 Carcinoma
in situ.
Syncytial aggregate with indistinct cell
borders and multiple isolated bare nuclei. Compare the size with the
intermediate squamous cells and columnar cells in the upper half of this field.
Nuclei have sharply outlined membranes, an irregular distribution of finely
granular chromatin, and nuclear grooves (Papanicolaou x HP).
Fig. 8.87 Carcinoma
in situ.
Coarsely granular irregularly distributed nuclear
chromatin. Large irregular condensations of chromatin—chromocenters—
should be differentiated from nucleoli. (Papanicolaou x OI).
Nuclear Morphology.
The lack of a differentiation stimulus,
usually associated with relatively rapid cell growth, becomes
apparent from the round-to-oval shape of the nuclei. On the
average, nuclei of cells derived from carcinoma in situ are usu-
ally somewhat smaller than nuclei derived from dysplastic cells.
Patten computed a mean nuclear area of 125 pm2.12 The nuclear
membrane in isolated cells is usually well defined; at higher
magnification, nuclear grooves may be seen and are rather
characteristic of these undifferentiated cells, even though they
are most likely artifacts due to fixation (Fig. 8.87; see also Fig.
8.86) . The chromatin varies from finely granular and unevenly
distributed to coarsely granular and hyperchromatic (see Fig.
8.87) . The number of small nuclei with coarse hyperchromatic
chromatin is correlated with the degree of dedifferentiation of
the cells from the carcinoma in situ. Another characteristic of
carcinoma in situ cells, recognizable at high magnification, is
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