Turkish Journal of Pathology

Türk Patoloji Dergisi

Turkish Journal of Pathology

Turkish Journal of Pathology

2012, Vol 28, Num, 2     (Pages: 134-141)

Metaplastic Breast Carcinomas and Their Relationship with Basal-Like Phenotype

Aslı ÇAKIR 1, İpek Işık GÖNÜL 1, Ömer ULUOĞLU 1

1 Department of Pathology, Gazi University, Faculty of Medicine, ANKARA, TURKEY

DOI: 10.5146/tjpath.2012.01112
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Objective: Metaplastic carcinoma is a rare tumor showing high histological grade and low hormone receptor expression. It has pure epithelial and mixed types. Studies have suggested that metaplastic carcinomas may have a basal-like profile. Our aim was to evaluate the clinicopathological features of 11 metaplastic carcinomas and determine their resemblance to basal-like breast carcinomas regarding their morphological and immunohistochemical profile.

Material and Method: Eleven metaplastic carcinoma cases were reviewed for their histopathological features. All tumors but one were evaluated for the immunohistochemical expressions of the cytokeratin 5/6, cytokeratin 14 and epidermal growth factor receptor; and hormonal status was assessed.

Results: Four of eleven cases were carcinoma with chondroid metaplasia, 3 were adenosquamous carcinoma, 2 were squamous cell carcinoma and 2 were carcinosarcoma. The mean patient age was 53 years and the mean tumor size was 5,1 cm. Histological grade was 3 for all with a nuclear grade of 3. Average mitotic count was 31/10 high power fields. Four cases had a central scar, 5 had central necrosis and 7 had geographic necrosis. Tumor growth pattern was pushing in 6 cases and no carcinoma in-situ was identified in 5 cases. Seven of 10 patients had axillary lymph node metastasis. Seven of 10 cases were triple-negative (estrogen receptor-, progesterone receptor-, HER2-) and 6 of them were positive for cytokeratin 5/6 and/or epidermal growth factor receptor, consistent with basal-like immunophenotype. Cytokeratin 14 was positive in 7 cases.

Conclusion: Metaplastic carcinomas are large-sized, high-grade tumors with prominent nuclear pleomorphism and frequent mitosis. They rarely overexpress hormone receptors and HER2 and generally have basal-like immunophenotype.

Keywords : Breast, Carcinoma, Metaplasia