Case Report: A Metaplastic Like Triple Negative Breast Cancer with Good Prognosis Histological Subtype

Abstract

Background:We report here the clinical case of a patient with low-grade metaplastic carcinoma, which represents a very rare subtype of breast cancer characterized by its triple-negative molecular profile but associated with a favourable prognosis. In this report, we present the diagnostic complexity of this subtype and review the literature to extract the principles of current management. Case presentation:A 77-year-old woman presented with a lesion of the left breast classified as ACR 4 during a screening examination. Microbiopsy revealed a grade 3 non-specific metaplastic carcinoma, finally requalified after lumpectomy as a grade 2 fibromatosis-like metaplastic carcinoma.Treatment by lumpectomy associated with adjuvant radiotherapy was finally retained after analysis of the literature and iterative discussion in multidisciplinary consultation meetings. Conclusion:This clinical case underlines the importance of the analysis of the whole lesion with a better immunohistochemical and molecular description that can conduct to a therapeutic de-escalation for the subtypes with good prognosis. Thus, the management of local triple negative metaplastic breast carcinoma is based on surgery with large margin alone. Nether less due to the few number of case around the world the level of evidence is still low and it is essential to continue a long-term survey after the treatment for improving the disease management.