Malignant myoepithelioma of the breast (MMB); An interesting case report with pathological, immunohistochemical findings and review of literature

• Published in: Human pathology : case reports 2019-09, Vol.17, p.200301-200301, Article 200301
• Main Authors: Harb, Ola A, Obaya, Ahmed A, Baiomy, Taha A, Gertallah, Loay M, Yousif, Sherif Y
• Format: Article
• Language: English
• Subjects: Breast; Immunohistochemistry; Malignant myoepithelioma; Pathology
• ISSN: 2214-3300; 2214-3300
• DOI: 10.1016/j.hpcr.2019.200301

AbstractBackgroundMalignant myoepithelioma (MMB) of the breast is an extremely rare and aggressive malignant tumor. The biological behavior of such malignancy and treatment outcomes of patients has not been clearly determined.HypothesisMMB is morphologically difficult to be distinguished from benign spindle cell proliferations. Identification and further research on the genesis of these tumors could help to discover new molecular targets for its management.Case reportWe herein describe the pathological and immunohistochemical characteristics of a case of MMB in a 51 year-old woman to add to the previous data about biological behavior and management strategy of such a rare aggressive entity.We have confirmed the diagnosis of our case using immunohistochemisrty because malignant cells revealed diffuse expression of P63, SMA and S-100 in addition to high Ki-67 labeling index.ConclusionsMMB is extremely rare entity which showed be suspected during differential diagnosis of any malignant spindle cell tumor of the breast.