922
Chapter 33
be classified as T4b or T4c.”
221
Patients with IBC tend to
be younger than women with locally advanced carcinoma
without an inflammatory component, and their tumors are
more likely to be ER negative.
226,245–247
A substantial num
ber of patients with IBC present with enlarged regional
lymph nodes.
234
IBC may be mistaken for a non-neoplastic
inflammatory condition because of its rapid onset and the
main symptom of pain.
220
Diffuse leukemic or lymphoma
tous involvement of the breast may simulate inflammatory
carcinoma.
Immunohistochemistry and Molecular Studies
The primary tumor of IBC has been negative for ER and PR
in up to 83% of cases.
246,248–251
HER2 overexpression was
found significantly more often in inflammatory (41%) than
in noninflammatory (19%) breast carcinomas,
249
and there
was a trend toward more frequent amplified expression of
HER2/
neu
in cases with negative ER or with positive lymph
nodes. In another study, all 22 samples of IBC were immu
noreactive for HER2.
248
A transplantable xenograft model of
human inflammatory carcinoma displayed the same absence
of ER and PR and EGFR as the primary tumor used to de
velop the xenograft.
252
Overexpression of p53 occurs in up to 84% of IBC.
253–255
Charafe-Jauffret et al.
256
reported that IBC was characterized
by the following immunophenotype: high E-cadherin expres
sion, ER negativity, highMIB1 proliferative index, cytoplasmic
MUC-1 (mucin glycoprotein) expression, and HER2 overex
pression. If all five features were present, there was a 90.5%
chance that a tumor was inflammatory carcinoma. There was
a 75% likelihood of this diagnosis when any four of five mark
ers were found. The prognosis for patients with non-IBC that
expressed four or five of these markers was not significantly
different from the prognosis for patients with IBC.
256
Clinical Features
IBC is primarily a clinical diagnosis characterized by ery
thema of the mammary skin (Fig. 33.30). Typically, the skin
is thickened, especially at the edge of the erysipeloid area,
with
peau d’orange
changes that are usually more conspic
uous over dependent portions of the breast.
234–236
The cu
taneous changes are due to lymphedema initiated by tumor
emboli within dermal lymphatic channels. These changes
may extend to the skin of the chest wall (Fig. 33.31). In ad
vanced cases, the breast is diffusely indurated or a mass can
be palpated centrally, but the lesion may not be palpable in
earlier stages of the disease.
237
Mammography usually dem
onstrates skin thickening, and within the breast there may
be a mass or diffusely increased parenchymal density.
238–241
However, cutaneous edema is not a specific radiologic fea
ture of inflammatory carcinoma.
236,242
Calcifications may
be present in the parenchymal tumor. Skin thickening,
mass lesions, axillary lymphadenopathy, and other abnor
malities may be evident on ultrasound examination of the
patient with inflammatory carcinoma.
241
Positron emission
tomography with computerized tomography (PET-CT)
and MRI have proven to be particularly effective for the
diagnosis of IBC.
243,244
Cutaneous erythema is sometimes localized to the re
gion overlying a palpable tumor. Detection of a mass
may precede the appearance of the skin change. Despite
Haagensen’s original requirement that the lesion involve at
least one-third of the mammary skin to qualify as IBC
232
—a
definition still used in the latest AJCC-TNM guidelines
221
—
it has been noted that the prognosis of patients with less
extensive cutaneous changes may be just as grave as that of
women with classical inflammatory carcinoma.
245
Accord
ing to current guidelines, the “rare case that exhibits all the
features of inflammatory breast carcinoma, but in which
skin changes involve less than one-third of the skin, should
FIG. 33.30.
Primary inflammatory carcinoma.
A:
Cutaneous erythema predominantly over the
dependent part of the breast.
B:
Most of the swollen breast is involved, and there is desquamation
of the skin.
