Twelve cases of metaplastic carcinoma of the breast: experience of the university hospital of Fez Morocco.

Introduction: Metaplastic breast carcinoma (MBC) is a distinct invasive breast carcinoma. It is a rare and heterogeneous group of malignancies, generally characterized by hormone receptor and human epidermal growth factor receptor 2 (HER2) negativity. The aim of the study is to evaluate epidemiological aspects, clinical characteristics, pathological features and biological profile of MBC cases diagnosed in our institution.
Methods: All patients with MBC diagnosed and treated in our institution between January 2004 and June 2009 were included.
Results: Twelve patients were identified. The median age was 46.5 (range 35-57 years) and the average tumor size was 6.9 cm (3.5-18 cm). Seven cases were purely squamous cell carcinomas, one was an adenosquamous carcinoma and four cases were mixed epithelial and mesenchymal metaplastic carcinomas. Primary treatment was mastectomy in 11 patients and wide local excision in one patient. There was lymph node (LN) involvement in four patients. Three patients were stage IIA, eight were stage III (2 IIIA, 6 IIIB), and one was stage IV. Estrogen and progesterone receptors status and over expression of HER2 were assessed. Eleven tumors had a basal-like phenotype and one tumor had luminal B phenotype.
Conclusion: This study found a high incidence of MBC compared to Western countries. The tumors occur at an earlier age of onset and are usually diagnosed at a late stage with predominance of squamous cell carcinoma subtype. LN metastases are found in the third case and the tumors are most often basal-like phenotype significantly reducing therapeutic options.