380
Chapter 11
Extent of DCIS
The extent of DCIS ranges from one duct or 0.1 cm to
widespread involvement of multiple quadrants of the
breast.
261
Although exact determination of the extent of
DCIS may be “a wild goose chase,”
262
estimation of its di-
mension is significant for management purposes. The size
of DCIS can be accurately assessed by measuring micro-
scopic extent only when it is present on a single slide.
263
Estimating the size of DCIS from the radiologic extent of cal-
cification or by recording the number blocks can result in ei-
ther overestimation or underestimation, particularly in cases
where the sections are not taken consecutively. It has been
suggested that assessment of DCIS using the block method
underestimates size with a mean reduction of 33%.
In a study of 33 patients with a histologically proven
DCIS by needle biopsy, the mean lesion size was 25.6 his-
tologically, 28.1 mm by MRI, and 27.2 mm on mammog-
raphy. The correlation coefficient between histopathologic
measurement and MRI was 0.831 versus 0.674 between his-
topathology and mammography. The correlation coefficient
Subclassification of DCIS to distinguish between com-
edo and noncomedo variants may be suggested by FNA
cytology.
258–260
The aspirate from “comedo”-type, that is,
solid-type DCIS with high nuclear grade, typically consists
of pleomorphic, loosely cohesive cells with poorly differen-
tiated nuclei and prominent nucleoli, sometimes accompa-
nied by mitotic figures. Necrotic debris that may contain
calcifications is usually present. Specimens from noncom-
edo DCIS tend to contain more cohesive three-dimensional
cell clusters with a papillary or cribriform configuration, as
well as dispersed cells distributed singly or in small groups
(Fig. 11.64). Nuclei are intermediate to low grade cytologi-
cally, and they usually lack prominent nucleoli. Necrosis and
an inflammatory cell background are found much less often
in aspirates from noncomedo DCIS.
Although the foregoing cytologic features may be reliable
for distinguishing between classic examples of lesions such
as solid-type DCIS with high nuclear grade and orderly crib-
riform DCIS, there are circumstances in which the findings
are not clear. This can occur when the intraductal carcinoma
has nuclei of variable grade nuclei.
FIG. 11.64.
DCIS, cribriform, cytology.
A:
Irregular flat sheet of cells with a microlumen in an FNA
smear.
B:
Three adjacent microlumens are apparent in the epithelium with low-grade nuclear
cytology.
C,D:
Epithelial clusters with low-grade nuclei on
ThinPrep
(C)
and on
Diff-Quik
stain
(D)
.
C
D
