Ductal Carcinoma
In Situ
335
diagnosed during 1973 to 1974 in Japan and the United
States reported a higher frequency of DCIS in Japanese pa-
tients and noted that the carcinomas tended to form bulky,
palpable tumors in Japanese women.
75
Pandya et al.
74
com-
pared the characteristics of DCIS detected in eras prior to
(1969 to 1985) and after the “intensified use of screening”
(1986 to 1990) at the Lahey Clinic. The proportion of mam-
mographically detected cases increased from 19% to 80%,
whereas palpable lesions decreased from 54% to 12%. The
proportion of cases presenting with duct discharge and Paget
disease also decreased. Comedo DCIS was found in 7% and
38% of palpable and mammographic lesions, respectively.
Currently, DCIS is not palpable in the majority of patients
with this disease.
76
Negative mammograms may be reported
in up to 25% of cases, with a sensitivity ranging from 56% in
women younger than 40 years to 67% in the 40- to 49-year
age group and 76% in those 50 years or older.
32
Nonpalpable
lesions are detected because of imaging findings, Paget dis-
ease, nipple discharge, or as an incidental finding in a bi-
opsy for a concurrent palpable benign tumor
41,76
(Fig. 11.2).
About 25% of biopsy procedures performed for “suspicious”
calcifications reveal carcinoma, largely of the intraductal
type.
77,78
Duct hyperplasia and sclerosing adenosis (SA) ac-
count for the majority of “significant” calcifications that do
not prove to be carcinoma. Comedocarcinoma is the type
most frequently detected by mammography alone, whereas
micropapillary DCIS is more often found as a result of a pal-
pable lesion or other clinical signs.
76
Frozen Section Evaluation
The diagnosis of DCIS requires histologic sections of ex-
cised breast tissue. DCIS can be recognized in frozen sec-
tions (FSs), but if any difficulty is encountered, the decision
should be immediately deferred to permanent sections be-
cause there is a significant risk of trimming away the lesional
area if more FSs are made.
79
FS is not appropriate for the
diagnosis of mammographically detected, nonpalpable le-
sions, unless there are exceptional clinical circumstances. In
one study of DCIS, 50% of the lesions were diagnosed at the
time of FS, 36% were reported to be benign, 8% were de-
ferred, 5% were diagnosed as atypical hyperplasia, and one
case was diagnosed as invasive.
80
Approximately 3% of biop-
sies reported to be benign at FS prove to contain carcinoma
when paraffin sections are examined.
79
Because the sampling
of a biopsy is limited during surgery, approximately 20% of
patients with a FS diagnosis of DCIS prove to have invasion
after multiple paraffin sections of the same biopsy specimen
were examined.
81
The use of FS evaluation of margins in breast-conserving
surgery has been shown to decrease reoperative rates; how-
ever, “technical changes in freezing breast tissue,” specifi-
cally those with “high adipose content,” is a major limitation
of such analyses besides the obvious difficulty in interpre-
tation of “atypical ducts.”
82
The possibility of “skip lesions”
of DCIS must be kept in mind when assessing margins of
lumpectomies (and nipple margins in nipple-sparing mas-
tectomies) by FS analyses.
83
Ultrasound Evaluation
Ultrasound is only uncommonly helpful in diagnosing
DCIS. In general, “ductal changes” with associated micro-
calcifications are the most common sonographic findings
in about one-third of the cases of high-grade DCIS, and an
irregular hypoechoic mass with an indistinct margin is the
most frequent finding in about one-third of non–high-grade
DCIS cases.
58
Magnetic Resonance Imaging
Magnetic resonance imaging (MRI) has proven to be an ef-
fective method for detecting DCIS, especially lesions that
lack calcifications. Menell et al.
60
found that MRI was more
sensitive than mammography for detecting DCIS overall and
for detecting multifocal DCIS. Lesion detection is based on
the finding of contrast enhancement in breast parenchyma
after injection of a gadolinium contrast agent compared
with the preinjection image.
61–63
Orel et al.
64
described three
patterns of enhancement associated with DCIS: ductal, re-
gional, and a peripherally enhancing mass. The mean size of
MRI-detected DCIS was 10 mm. Correlation of immunohis-
tochemical studies for vascularity and MRI characteristics of
the lesions suggested that tumor angiogenesis contributed to
MR enhancement in one series.
61
Contrast-enhanced MRI
has proven to be an effective method for the detection of
concurrent, unsuspected contralateral carcinoma in women
with ipsilateral DCIS.
65
MRI has higher sensitivity for invasive carcinoma (up to
98%) than for DCIS (sensitivity of 60% to 80%).
66
On MRI,
DCIS typically has a non-mass, delayed peak enhancement
profile; however, this methodology has a high rate of false neg-
atives. Gadolinium, the contrast media used in MRI, has been
shown to accumulate within the intraductal space of DCIS.
67
Current
indications
for adjunct MRI include the detec-
tion of an occult primary tumor, the examination of dense
breast tissue, the presence of known
BRCA
mutations, and
the detection of chest wall involvement.
68
MRI has two main
roles
in the evaluation of DCIS. The first is assessing the ex-
tent of disease, and the other is early detection in breast can-
cer screening programs.
The sensitivity of MRI for the accurate assessment of
DCIS is more than 60%, compared with approximately 55%
for mammography and 45% or so for ultrasound
69
; MRI
screening may potentially double the probability of carci-
noma detection in a high-risk population compared with
either mammography or ultrasound alone.
68,70
Owing to the
higher detection rate of otherwise occult significant disease
on MRI (including so-called “elsewhere carcinoma”), there
is a strong association between preoperative MRI performed
in women with DCIS and mastectomy.
71
Palpable DCIS
Prior to the widespread use of mammography, palpable
tumors were reportedly present in 50% to 65% of women
who had DCIS.
72–74
A study comparing breast carcinomas
