Summary: Prepared by
David T. Boyd, MD, Pouneh Razavi, MD,
Erini Makariou, MD,
Department of Radiology,
Pedro Debrito, MD,
Department of Pathology, and
Shawna C. Willey, MD,
Department of Surgery, Georgetown University Hospital,
Summary: CASE SUMMARY
Summary: A 48-year-old Hispanic woman with no significant medical history
presented with a rapidly enlarging, palpable, painful left breast
mass. On examination, the breast mass was located centrally,
measured approximately 10x9 cm, and was tender to palpation. The
nipple was flattened and hyperpigmented (Figure 1). There was no
palpable axillary, cervical, or supraclavicular
Metaplastic ductal carcinoma of the breast with a predominant
Sonographically guided incisional core needle biopsy revealed a
malignant spindle cell neoplasm containing osteoclastic-like
giant cells with a focal production of osteoid-type matrix.
The patient underwent a left total mastectomy. The removed tumor
measured 7 cm in greatest dimension and had a significant
hemorrhagic component (Figure 8). The surgical margins were
negative for malignancy.
The final histopathologic diagnosis was metaplastic carcinoma
with a predominant osteosarcomatous differentiation (>99% of
thetumor volume) (Figure 9) and minor components of poorly
differentiated infiltrating ductal carcinoma, not otherwise
specified (Elston Score = 8), and high-grade intraductal carcinoma,
cribriform-type with apocrine features (Figure 10).
Immunohistochemical stains verified the metaplastic nature of
this carcinoma. These tissues were negative for estrogen and
progesterone receptors and for the HER-2/neu immunostain.
Left sentinel lymph node excisional biopsy revealed 2 lymph
nodes without evidence of local metastatic carcinoma. This finding,
combined with the fact that hemorrhage made up much more of the
gross tumor volume than actual solid tumor, contributed to the
decision not to perform a full axillary dissection. The patient
tolerated the surgery well, and received postsurgical chemotherapy
and radiation therapy. No distant metastases have been identified,
and no local recurrence has been seen.
Mammography revealed a large, 4.8-cm, dense, round,
well-circumscribed mass that corresponded to the palpable mass
(Figure 1). It also showed clustered dystrophic and pleomorphic
calcifications at the posterior edge of the mass (Figure 2).
B-mode sonography showed a hypoechoic complex mass at 12 o'clock
in the retroareolar position that measured 4.8x4.7x3.4 cm. The mass
had solid and cystic components and multiple fluid-fluid levels.
These findings suggested a solid tumor with regions of hemorrhage
and cystic necrosis (Figure 3).
Using a 1.5T magnet with a dedicated breast coil, magnetic
resonance imaging (MRI) with gadolinium contrast depicted a large
dominant mass in the center of the left breast that measured
5.5x6.3x6.1 cm. The mass extended anteriorly to the areola.
Markedly enlarged vessels circumscribed and traversed this lesion.
On T1-weighted (T1W) precontrast fat-suppressed MR images, foci of
increased and decreased signal intensity were seen within this
hypointense mass. These MRI findings suggested regions of
hemorrhage and necrosis, respectively (Figure 4). On short tau
inversion recovery (STIR) images, the large mass showed
hyperintensity. Areas of especially high signal intensity centrally
suggested necrosis (Figure 5). On T1W postcontrast digital
subtraction images, this mass exhibited heterogeneous contrast
enhancement (Figure 6). Utilizing T1W post contrast images, the
mean curve illustrated rapid uptake of contrast followed by rapid
washout (Figure 7). These features were all suggestive of
malignancy. The breast mass did not extend into the chest wall. No
suspicious contralateral breast lesion was identified.
Metaplastic ductal carcinoma of the breast is a well-recognized
but rare manifestation of poorly differentiated invasive carcinoma,
which contains both epithelial (ductal) and mesenchymal elements,
and represents <1% of all breast
carcinomas.1-3Osseous metaplasia is a veryrare
manifestation of metaplastic carcinoma, occurring in only 0.2% of
all breast carcinomas.4
Clinically, metaplastic carcinoma has similar features to those
of breast carcinoma in general.2,3,5,6 As studies of
similar cases of metaplastic carcinoma by Gunhan-Bilgen et
al2(n = 8), Velasco and colleagues3(n = 12),
and Patterson and coworkers7(n = 9) found that patients
usually present at approximately the age of 50 with a palpable
breast mass. Also similar to these series, our patient’s
metaplastic tumor was relatively large in size (7 cm), but lacked
local or distant metastasis at presentation.2,3,5,7 This
case of infiltrating ductal carcinoma with osseous metaplasia is
unusual enough to not be definitely identified in any of these
larger series.2,3,7 In contrast, the case reported by
Evans et al4 of infiltrating ductal carcinoma with
osseous metaplasia is most analogous to ours, as their patient
exhibited similar clinical features. The 47-year-old woman
presented with a palpable mass measuring 5.5 cm.4
On mammography, well-circumscribed masses tend to indicate benign
disease.2,3,5,7 However, metaplastic carcinomas also
tend to be well-circumscribed, as in this case. Therefore, it
should be included in the differential diagnosis, especially if the
mass enlarges rapidly, as in this case, to avoid delay in proper
treatment.2-6,8,9 As in the patient reported by Evans et
al4 and in all 12 cases in the series from
Gunhan-Bilgenet al,2 this particular tumor lacked
spiculations, a feature that has been previously described for
metaplastic carcinoma by Patterson et al7and
others.3,8 Such lack of spiculation may result from the
fact that this tumor had only a very minor component of
infiltrating ductal carcinoma (<1% of tumor volume), which tends
to correspond to spiculaton on mammography.7 These
findings suggest that shape and border regularity may not be enough
to distinguish metaplastic carcinomas mammographically.
Metaplastic carcinoma’s high-density relative to surrounding
fibroglandular tissue, as seen in this case, is a mammographic
feature with widespread agreement.2,3,7 The especially
high density seen here, as well as in Evan’s4 case,
likely reflects the significant osseous matrix seen in both cases.
Associated calcifications, as seen here, have not been commonly
seen, but have been reported by
Valasco,3 Brenner,8 and
On sonography, this tumor exhibited complexity with both solid
and cystic components features that were also identified in 6 out of
8 ultrasound cases (75%) in the studies by Velasco et
al,3 but in only 1 of 8 ultrasound cases (12.5%) in the
series reported by Gunhan-Bilgen.2 However, even
Gunhan-Bilgen's group2 noted that breast masses with
solid and cystic components should include metaplastic carcinoma in
the differential diagnosis.
On MRI, this highly vascular tumor exhibited heterogeneous
contrast enhancement with a rapid uptake of contrast followed by
rapid washout, along with associated necrosis and hemorrhage. These
features are consistent with a malignant lesion rather than a
benign one, which helps to further delineate mammographic and
sonographic findings.9 All of the MRI cases reported by
Velasco et al3 showed contrast enhancement.
Additionally, the necrosis-related T2 hypersignal that is
frequently associated with this type of tumor was identified in 11
of 12 of the cases from Velasco et al3 and was also seen
in this case. Hence, MRI helps to better characterize metaplastic
carcinoma, after mammography and sonography have been
As Kurian and Al-Nafussi5 note, the main differential
pathological diagnosis in this case included primary breast
osteosarcoma versus our ultimate diagnosis, metaplastic ductal
carcinoma with osteosarcomatous differentiation. This distinction
has clinical ramifications affecting surgical treatments and
chemotherapy regimens because breast sarcoma metastasizes even less
frequently than metaplastic ductal carcinoma.7,11
Sonographically guided core biopsy tissue samples alone could not
distinguish between the two. The examination of the much larger
surgical specimen revealed that, although the bulk of the tumor
represented high-grade osteosarcoma (99% of tumor volume), the
presence of adjacent foci of infiltrating ductal carcinoma and
high-grade intraductal carcinoma indicated that the tumor was much
more likely to be a metaplastic ductal carcinoma with
osteosarcomatous differentiation than a primary extraskeletal
mammary osteo sarcoma.5
Metaplastic ductal carcinoma of the breast accounts for <1%
of all breast carcinomas. This case, which involved a predominant
osteosarcomatous differentiation, is an even rarer entity.
Mammography, sonography, and MRI all play helpful roles in
characterizing this tumor before the pathological diagnosis is
- Catroppo JF, Lara JF. Metastatic metaplastic carcinoma of the
breast (MCB): An uncharacteristic pattern of presentation with
clinicopathologic correlation. Diagn Cytopathol.
- Gunhan-Bilgen I, Memis A, Ustun EE, et al. Metaplastic
carcinoma of the breast: Clinical, mammograph ic, and sonographic
findings with histopathologic correlation.AJR Am J
- Velasco M, Santamaria G, Ganau S, et al. MRI of metaplastic
carcinoma of the breast. AJR Am J Roentgenol.
- Evans HA, Shaughnessy, EA, Nikiforov YE. Infiltrating ductal
carcinoma of the breast with osseous metaplasia: Imaging findings
with pathologic correlation. AJR Am J Roentgenol.
- Kurian KM, Al-Nafussi A. Sarcomatoid/ metaplastic carcinoma of
the breast: A clinicopathological study of 12 cases.
- Oberman HA. Metaplastic carcinoma of the breast: A
clinicopathologic study of 29 patients. Am J Surg Pathol.
- Patterson SK, Tworek JA, Roubidoux MA, et al. Metaplastic
carcinoma of the breast: Mammographic appearance with pathologic
correlation. AJR Am J Roentgenol. 1997;169:709-712.
- Brenner RJ, Turner RR, Schiller V, et al. Metaplastic carcinoma
of the breast: Report of three cases. Cancer.
- Buadu LD, Murakami J, Murayama S, et al. Breast lesions:
Correlation of contrast medium enhancement patterns on MR images
with histopathologic findings and tumor angiogenesis.
- Park JM, Han BK, Moon WK, et al. Metaplastic carcinoma of the
breast: Mammographic and sonographic findings. J Clin
- Moore MP, Kinne DW. Breast sarcoma. Surg Clin North