Malignant transformation in a Breast Adenomyoepithelioma Caused by Amplification of c-MYC: A Common pathway to Cancer in a Rare Entity

Adenomyoepithelioma of the breast with malignant transformation and repeated local recurrence: A case report

BACKGROUND

Adenomyoepithelioma (AME) of the breast is a rare type of benign breast tumor. Many AMEs show benign behavior, but reports of the malignant type are rare. We present the case of a patient with AME with repeated local recurrences and further malignant transformation.

CASE SUMMARY

A 53-year-old woman visited our hospital with a 16-mm palpable mass in the right breast. A core needle biopsy was performed. The pathological diagnosis was AME. Lumpectomy with a safety margin was performed without axillary lymph node dissection (ALND). Two years later, local recurrence developed, and the patient again underwent lumpectomy with a safety margin. The pathology showed malignant AME, and the margin was negative. Eight months later, local recurrence developed again in the same location, and a total mastectomy was performed without ALND. The pathological diagnosis was malignant AME. The patient was disease-free for three years posttreatment.

CONCLUSION

The treatment of AME requires caution, as it may exhibit repeated recurrences after local excision as well as malignant transformation.

Adenomyoepithelioma of the breast: a proposal for classification

Breast lesions with a prominent myoepithelial cell component constitute a heterogeneous group of benign and malignant neoplastic proliferations. These lesions are often dual epithelial-myoepithelial, but may be purely myoepithelial cell in nature. Benign epithelial-myoepithelial lesions typically maintain the morphology and immunophenotype of the normal bilayer epithelial myoepithelial structures. However, the distinction between the two cell components is not always clear-cut in malignant lesions in which the histogenesis of myoepithelial cells remains uncertain. Neoplastic biphasic epithelial-myoepithelial lesions of the breast include adenomyoepithelioma (AME), pleomorphic adenoma and adenoid cystic carcinoma. Four histological patterns of classical AME have been described: tubular, lobulated, spindle-cell and adenosis variants. Overlapping patterns occur and some AMEs display an intraductal papillary pattern that may represent a fifth variant. AME can be benign or malignant. Classical AME may show atypical features, which are not sufficient for the diagnosis of malignancy (atypical AME). Atypical AME is recognised as a lesion of uncertain malignant potential with limited metastatic capability. Based on the histological features, we propose a classification of malignant AME (M-AME) into three variants: M-AME in situ, M-AME invasive and AME with invasive carcinoma. In this review, we provide an overview of myoepithelial lesions of the breast focusing on the classification of AME to improve not only the consistency of reporting but also help to guide further management decision-making.

C-Myc Signaling Pathway in Treatment and Prevention of Brain Tumors

Brain tumors are responsible for high morbidity and mortality worldwide. Several factors such as the presence of blood-brain barrier (BBB), sensitive location in the brain, and unique biological features challenge the treatment of brain tumors. The conventional drugs are no longer effective in the treatment of brain tumors, and scientists are trying to find novel therapeutics for brain tumors. In this way, identification of molecular pathways can facilitate finding an effective treatment. c-Myc is an oncogene signaling pathway capable of regulation of biological processes such as apoptotic cell death, proliferation, survival, differentiation, and so on. These pleiotropic effects of c-Myc have resulted in much fascination with its role in different cancers, particularly brain tumors. In the present review, we aim to demonstrate the upstream and down-stream mediators of c-Myc in brain tumors such as glioma, glioblastoma, astrocytoma, and medulloblastoma. The capacity of c-Myc as a prognostic factor in brain tumors will be investigated. Our goal is to define an axis in which the c-Myc signaling pathway plays a crucial role and to provide direction for therapeutic targeting in these signaling networks in brain tumors.