Breast Metaplastic Carcinoma With Osteosarcomatous Differentiation: A Case Report and literature Review

Abstract

Metaplastic breast carcinoma (MBCs) is a rare heterogeneous group of malignancies. Herein, we report a case of metaplastic breast carcinoma, which had 2 components. One of them was typical invasive ductal carcinoma (IDC), the other one was presenting as osteosarcoma with lots of immature trabeculae. The results of immunohistochemistry showed different presentations between them. The majority of MBCs show triple-negativity for ER, PR, and HER-2 and are thus associated with poor prognosis. Our report shows that, it is necessary to describe the proportion of the components and the presentations of immunohistochemistry in the diagnosis, which will be important to develop specific and effective therapies.

Osteosarcoma Originating From a Malignant Phyllodes Tumor: A Case Report of a Rare Malignancy

“…This tumor needs to be distinguished from metaplastic cancer, and to diagnose it, the tumor epithelial component must be confirmed on immunohistochemistry. The majority of metaplastic carcinoma exhibit immunopositivity for p63 and cytokeratin (CK) [13].…”

Metaplastic carcinoma with osteosarcomatous differentiation in the breast: Case report

“…Metaplastic breast carcinoma is a heterogeneous group of malignant neoplasms of the breast comprised of malignant invasive breast carcinoma and an admixed non-gland-forming component [3] . Less than 5% of breast carcinomas demonstrate metaplastic pathology, with subtype differentiation including squamous, spindle, matrix-producing, and those demonstrating frank heterologous sarcomatous differentiation [3 , 9] . Heterologous sarcomatous differentiation is the least common subtype of metaplastic breast carcinoma, in which case the sarcomatous component is typically high-grade and aggressive [9] .…”

“…Less than 5% of breast carcinomas demonstrate metaplastic pathology, with subtype differentiation including squamous, spindle, matrix-producing, and those demonstrating frank heterologous sarcomatous differentiation [3 , 9] . Heterologous sarcomatous differentiation is the least common subtype of metaplastic breast carcinoma, in which case the sarcomatous component is typically high-grade and aggressive [9] . Frequently, the tumors will not demonstrate KIT activating mutations, but upregulation of EGFR copies [3] .…”

“…MBC is usually triple negative and in general portends a worse prognosis and 5-year survival than triple-negative breast carcinomas without metaplastic features [5 , 8] . Osseous and sarcomatous differentiation are the rarest mesenchymal subtypes of MBC and are typically poorly differentiated [9] with osteosarcomatous differentiation accounting for between 0.003% and 0.12% of all breast cancer cases [10 , 11] . We present a case of a 61-year-old female with a history of previously treated left invasive ductal carcinoma with subsequent diagnosis of a triple negative metaplastic left breast carcinoma with osteosarcomatous differentiation approximately 7 years after an initial breast cancer diagnosis.…”

Rapidly progressive metaplastic breast cancer: a case report from Latin America

“…4 This type of tumor was initially described in 1973 and is characterized by presenting a partial or total differentiation of the tissue that conforms it to a squamous, spindle cell, mesenchymal epithelium or other lines. 7,8 Being a triple negative breast cancer, these tumors have a poor prognosis and are characterized by being aggressive, chemo resistant and usually having metastatic involvement. Metaplastic cancers usually present as high-grade lesions, except for squamous and fibromatosis-like variants.4 It is also important to mention that this type of cancer tends to have TP53, pik3CA, and PTEN genetic alterations that may be possible drug targets in treatment, but which have not yet been established.…”