RESUMO
Metaplastic breast carcinoma (MBC) represents a rare subtype of breast cancer, characterized by poor prognostic indicators that have been recently identified. Clinical and radiological presentations often mimic other breast cancer types, necessitating immunohistochemistry (IHC) for accurate diagnosis. In this study, we report a case involving a 31-year-old female presenting with a painless, fixed, non-inflammatory mass in the left breast, which was confirmed as MBC. Treatment encompassed lumpectomy, chemotherapy, radiotherapy, and subsequent hormonal therapy. Understanding this rarely reported yet aggressive form of breast cancer holds significant importance for clinicians, enabling them to promptly establish a diagnosis and implement effective management strategies.