362
Chapter 11
FIG. 11.39.
DCIS in sclerosing adenosis in a needle core
biopsy.
A:
DCIS occupies the structure of SA. Groups of
carcinoma cells resemble invasive carcinoma cells. Immu-
nostains for SMM-HC
(B)
and SMA
(C)
on sections parallel
to
(A)
reveal myoepithelial cells enveloping the groups of
carcinoma cells.
A
C
B
DCIS. Coexistent
in situ
lesions have been found in asso-
ciation with invasive duct and invasive lobular carcinoma.
This pattern of
in situ
carcinoma should be distinguished
from lobular extension of DCIS, so-called lobular cancer-
ization. In the latter condition, the nonneoplastic lobular
epithelium is displaced by carcinoma cells with the same
cytologic appearance as the DCIS. As outlined earlier, the
E-cadherin stain, among others, can be used to identify
LCIS in DCIS. Computerized image analysis systems for
classifying various noninvasive proliferative and neoplastic
lesions on digitized slides are in development, and at this
time they have more potential as an educational tool rather
than as a stand-alone diagnostic tool.
146
Grading of DCIS
The interval between DCIS and the development of invasive
carcinoma is shorter for high-grade DCIS, averaging 5 years,
than for low-grade DCIS, which takes a mean period of
more than 15 years.
147,148
Grading of DCIS can also be useful
for predicting the risk of breast recurrence after conserva-
tion therapy. When there is an invasive element associated
with DCIS, both components tend to have similar nuclear
grades.
149
Grading schemes consisting of two categories
(high grade and all others) and three categories (high, inter-
mediate, and low) have been devised for DCIS. The deter-
mination of grade is based upon nuclear cytology
150
and the
growth pattern. Nuclear grade tends to be relatively constant
in a given patient, even when there is substantial variation in
architectural pattern.
149
The presence or absence of necrosis
may also be considered in grading.
In past decades, DCIS was routinely classified as being
of “comedo” or “noncomedo” types. In general, “comedo”
carcinoma implied solid type of DCIS with pleomorphic
cells bearing high-grade nuclei associated with abundant
central necrosis. The term “comedo” referred to necrotic
cellular debris that oozed from the cut surfaces of affected
ducts when the excised tumor was compressed (i.e., resem-
bling the “comedones” in acne vulgaris). The collective term
“noncomedo” DCIS in the premammographic era implied
all other types of DCIS. These noncomedo DCIS were rarer,
