Download Case 7 Clinical data: 38 year old female presented with unilateral

Case 7
Clinical data:
38 year old female presented with unilateral (left) breast pain and a palpable breast mass.
Mammography showed a 20x20x19mm hypoechogenic lesion with marked peripheral edema.
Clinical head and neck, respiratory tract, GIT and genitourinary tract examinations were all negative
for malignancy.
Gross description:
We received a 100x70x40mm partial mastectomy specimen. On sectioning, 2 distinct lesions (25mm
and 6mm in diameter) were discovered. A sentinel node biopsy was subsequently performed with
negative results.
Histology:
Both lesions had the same histological picture: invasive tumor comprising islands of cells of basaloid
appearance with focal squamous differentiation and abundant desmoplastic stroma. Central necrosis
was seen in some tumor islands. Rare tubule formation was also present.
Immunohistochemistry:
The tumor cells were CK18, CK7, CD10, ER, PR and HER2 negative. They showed strong diffuse
expression of p63 and p16. Ck5/6 and HMW were strongly expressed focally. Ki-67 was expressed in
90% of tumor cells.
Differential diagnosis:
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Metastasis of cervical squamous cell carcinoma to the breast
Metastasis of head and neck squamous cell carcinoma to the breast
Neuroendocrine carcinoma
Invasive ductal carcinoma NOS
Primary squamous cell carcinoma (metaplastic carcinoma) of the breast
Our diagnosis
Primary basaloid squamous cell carcinoma of the breast
Discussion
Metaplastic carcinomas of the breast are epithelial malignancies with partial or complete
transformation to a non-glandular epithelial or mesenchymal process. They account for less than 1%
of all breast malignancies. They may be grouped into 5 subtypes: i.) squamous cell carcinoma (SCC),
ii.) matrix-producing carcinoma, iii.) spindle cell carcinoma, iv.) carcinosarcoma and v.) metaplastic
carcinoma with osteoclast-like giant cells.
These tumors are often large and palpable, usually triple negative and frequently express basal
makers. About 70% of metaplastic carcinomas show EGFR gene amplification and protein
overexpression. Unlike other special histological types of triple negative breast cancer, metaplastic
carcinomas appear to be inherently aggressive and associated with poorer prognosis than invasive
ductal carcinoma NOS. Over 50 % of the patients develop local or distant metastasis within 5 years.
The absence of SCC at a non-breast site and the absence of skin involvement are required in order for
the diagnosis of primary metaplastic SCC to be made. Also, over 50 % of the tumor must show
squamous differentiation.
Most authors suggest that this type of breast cancer originates from squamous metaplasia such as
can be found in fibroepithalial lesions, papillomas and inflammatory lesions. Others suggest
myoepithelial or embryologic (ectodermic) origins.
Treatment does not differ from that of invasive ductal carcinoma.
Reference:
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Kuroda N, Fujishima N, Inoue K, Ohara M, Hirouchi T, Mizuno K, Hayashi Y, Lee G. Basal-like
carcinoma of the breast: further evidence of the possibility that most metaplastic carcinomas
may be actually basal-like carcinomas. Med Mol Morphol .2008;41:117-120
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Jung S, Kim H, Nam B, Min S, Lee S, Park C, Kwon Y, Kim E, Ko K, Shin K, Lee K, Park I, Lee S,
Kim S, Kang H, Ro J. Worse prognosis of metaplastic breast cancer patients than other
patients with triple-negative breast cancer. Breast Cancer Res Treat. 2010;120:627-63
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Rungta S, Kleer C. Metaplastic carcinomas of the breast: Diagnostic challenges and new
translational insights. Arch. 2012;136:896-900
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Yamaguchi R, Tanaka M, Kondo K, Yokoyama T, Maeda I, Tsuchiya S, Yamaguchi M, Takahashi
R, Ogata Y, Abe H, Akiba J, Nakashima O, Kage M, Yano H. Immunohistochemical study of
metaplastic carcinoma and central acellular carcinoma of the breast: central acellular
carcinoma is related to metaplastic carcinoma. Med Mol Morphol. 2012;45:14-21
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Grenier J, Soria J, Mathieu M, Andre F, Abdelmoula S, Velasco V, Morat L, Besse B, Dunant A,
Spielmann M, Delaloge S. Differential immunohistochemical and biological profile of
sqamous cell carcinoma of the breast. Anticancer Research. 2007;27:547-55