Abstract

Metaplastic carcinomas (carcinomas with metaplasia) of the breast are difficult to accurately diagnose and classify because of their rarity and varied histologic patterns. Cystic change can be encountered in mammary carcinoma, especially in carcinoma with squamous metaplasia, but are rare in pseudosarcomatous metaplastic carcinoma. We recently experienced a case of pseduosarcomatous metaplastic carcinoma in a 69-year-old female who had an extensive cystic change in radiologic and histopathologic findings. The precise cell type that gives rise to metaplastic carcinomas remains uncertain. Immunohistochemical findings raised the possibility of the myoepithelial nature of the tumor.

• Keywords: Breast;Metaplastic carcinoma;Cystic change;Immunohistochemistry