2014, Volume 30, Number 3, Page(s) 225-227
Primary Chondroblastic Osteosarcoma of the Breast
Mohamed Reda EL OCHI1, Fouad ZOUAIDIA2, Rachad KABAJ1, Hafsa EL OUAZZANNI1, Mohamed ALLAOUI1, Mohamed OUKABLI3, Abderrahman AL BOUZIDI3, Basma EL KHANNOUSSI1
1Department of Pathology, National Institute of Oncology, RABAT, MAROC
2Ibn Sina Hospital, RABAT, MAROC
3Mohamed V Military Hospital, RABAT, MAROC
Keywords: Breast, Osteosarcoma, Sarcoma
Pure sarcomas of the breast are uncommon, accounting for less
than 1% of primary breast malignant tumors. Mammary osteogenic
sarcomas are very rare and less than 100 cases have been reported
in literature. They mainly affect older and middle aged women and
are highly aggressive. We report an additional case in a 56-year-old
woman. Histological and immunohistological characteristics
were similar to those described in other localizations. Differential
diagnosis involves phyllodes sarcoma, breast metaplastic carcinoma
with chondroid and osteoid differentiation, osteosarcoma of the ribs,
and metastatic osteosarcoma. The prognosis is poor.
Extraskeletal osteosarcomas are uncommon neoplasms
representing less than 1% of soft tissue sarcomas. Mammary
sarcomas are also rare, accounting for less than 1% of all
primary breast malignant tumors. In this group, primary
osteosarcomas are one of the least common sarcomas of the
. Most cases have been reported in the literature as
case reports except Silver et al who reported a retrospective
analysis of 50 cases3
. With less than a hundred cases of
primary mammary osteosarcoma reported in the literature4,
we report an additional case with this unusual tumor.
A 56 year-old postmenopausal woman, without clinical
antecedent, presented with a breast lump that had rapidly
grown for 7 months. On examination, breast palpation
revealed a painless, mobile, hard, relatively regular shaped
and large mass of 11x8 cm, involving all four quadrants of
the right breast. There was no axillary lymphadenopathy.
Ultrasound showed a heterogenous hypoechoic solid mass.
Mammography showed a large hyperdense and round
mass with calcifications (Figure 1
). Biopsy was performed
and showed a high-grade sarcoma with chondromatous differentiation. Preoperatively, the staging did not reveal
primary or metastatic extramammarian sarcomatous
A mastectomy was performed. Grossly, a right mastectomy
specimen measuring 18x12x5cm was received. The tumor
was grey white, hard, with regular margins, measured
11x8.5x6 cm, and involved all four quadrants of the breast
with small areas of haemorrhage, cysts and necrosis.
Histological examination revealed chondrosarcomatous
proliferation, with foci of chondroid background containing
atypical neoplastic cells. Furthermore, there were solid and
compact sheets of spindle cells (Figure 2) producing an
osteoid and bony matrix (Figure 3). No areas of epithelial
component were identified despite achieving complete
section slices of the tumor. Nipple areolar areas, skin and
lymph nodes were free of tumor. On immunohistochemistry,
tumor cells displayed immunoreactivity for vimentin.
Positivity for S-100 and EMA was noted in chondroid areas
(Figure 4). The spindle cell component was positive for
smooth muscle actin but negative for desmin. Cytokeratin,
p63 and CD34 were all negative. Thus, a diagnosis of
primary chondroblastic osteosarcoma was made.
The search for a primary bone tumor, especially in the
rib cage, was negative. The patient presented with lung
metastasis 2 months after mastectomy. She died 3 months
Click Here to Zoom
|Figure 4: On immunohistochemistry cells of chondromatous
component were positive for S-100 protein (S100; x40).
Pure sarcomas of the breast are uncommon, accounting for
less than 1% of primary breast malignant tumors5,6
common breast sarcomas include fibrosarcomas, malignant
fibrous histiocytoma, angiosarcoma, and liposarcoma3,7
Primary mammary osteosarcoma of the breast represents
12.5% of breast sarcomas5,8
. Tumors with the following
criteria are considered ‘pure osteosarcoma’: absence of bone
origin, presence of osteoid or bony matrix, absence of an
epithelial differentiation, and absence of a benign tumor9
. The largest series, from the Armed Forces Institute of
Pathology, Washington in the U.S.A., reported 50 cases,3
Mammary osteosarcoma predominates in middle-aged
and older women3,9. Most often, they arise as de
novo conditions without predisposing factors especially
after radiation therapy3. The association between
osteosarcoma and fibroadenoma was previously reported4. The duration of symptoms is variable but most present
within few months3. All cases reported in literature had
Clinical features, mammographic and macroscopic
findings are not specific10. Mammographically, these
tumors are usually dense and well-circumscribed with
focal or extensive coarse calcifications5,11. They may
radiologically simulate a benign tumor5.
Microscopic findings of primary mammary osteosarcoma
are similar to skeletal and other extraskeletal osteosarcomas.
Considerable diversity in morphological appearance
has been reported with variants like fibroblastic,
osteoblastic, osteoclastic, and chondroblastic; a variable
amount of osteoid tissue and bone are present in all5.
Chondrosarcomatous differentiation is unusual3,10 but
was extensive in our case.
The histogenesis of this entity is unclear. It probably develops
from totipotent stromal cells or a transformation from
pre-existing fibroadenoma or phyllodes tumor3,5. The
main differential diagnosis is malignant phyllodes tumor
with osteosarcomatous component but also metaplastic
carcinoma, osteogenic sarcoma arising from the underlying
ribs or sternum, and metastatic osteosarcoma3,9.
In localized forms, the treatment is based on surgical
excision with clear margins. Lymph node metastases are
exceptional so that lymphadenectomy is not indicated12,13. There is controversy regarding the use of
chemotherapy. For some authors, it is not recommended
especially in localized and well-resected low-grade tumors13. Regarding metastasizing tumors, treatment is based
mainly on chemotherapy using conventional drugs for
osteosarcoma (doxorubicine, ifosfamide, cisplatinium,
The prognosis is poor and the five-year survival is 38%.
Recurrences are less frequent in patients treated with
mastectomy than those treated with local excision.
Metastases occur mainly in the lung; there is no axillary
node involvement in almost all cases9. Cases of death
occurring a few months after the diagnosis have been
1) Adem C, Reynolds C, Ingle JN, Nascimento AG. Primary breast
sarcoma: Clinicopathologic series from the Mayo Clinic and
review of the literature. Br J Cancer. 2004;91:237-41.
2) Young JL Jr, Ward KC, Wingo PA, Howe HL. The incidence of
malignant non-carcinomas of the female breast. Cancer Causes
3) Silver SA, Tavassoli FA. Primary osteogenic sarcoma of the
breast. A clinicopathologic analysis of 50 cases. Am J Surg Pathol.
4) B rustugun OT, Reed W, Poulsen JP, Bruland OS. Primary
osteosarcoma of the breast. Acta Oncol. 2005; 44:767-70.
5) B ahrami A, Resetkova E, Ro JY, Ibaņez JD, Ayala AG. Primary
osteosarcoma of the breast: Report of 2 cases. Arch Pathol Lab
6) Saber B, Nawal A, Mohamed F, Hassan E. Primary osteosarcoma
of the breast: Case report. Cases J. 2008;1: 80-1
7) Jacob S, Japa D. Primary osteogenic sarcoma of the breast. Indian
J Pathol Microbiol. 2010;53:785-6.
8) B lanchard DK, Reynolds CA, Grant CS, Donohue JH. Primary
non-phylloides breast sarcomas. Am J Surg. 2003;186: 359-61.
9) Murakami S, Isozaki H, Shou T, Sakal K, Yamamoto Y, Oomor
M, Toyoda H. Primary osteosarcoma of the breast. Pathol Int.
10) Sperberg JT, Clayton JW 3rd, Masters GA. Primary osteosarcoma
of the breast. Del Med J. 2005; 77:11-4.
11) Ribeiro-Silva A, Zambelli Ramalho LN, Zucoloto S. Phyllodes
tumor with osteosarcomatous differentiation: A comparative
immunohistochemical study between epithelial and mesenchymal
cells. Tumori. 2006;92:340-6.
12) Ellmann A, Jawa ZM, Maharaj M. Primary osteogenic sarcoma of
the breast detected on skeletal scintigraphy. Clin Nucl Med. 2006;
13) Irshad K, Mann BS, Campbell H. Primary osteosarcoma of the
breast. Breast. 2003;12:72-4.