MED12, TERT and RARA in fibroepithelial tumours of the breast. Issue 1 (29th October 2019)

• Record Type: Journal Article
• Authors: Chang, Huan Ying; Koh, Valerie Cui Yun; Md Nasir, Nur Diyana; Ng, Cedric Chuan Young; Guan, Peiyong; Thike, Aye Aye; Teh, Bin Tean; Tan, Puay Hoon
• Is Part Of: Journal of clinical pathology. Volume 73:Issue 1(2020)
• Page Start: 51
• Page End: 56
• Publication Date: 2019-10-29
• Subjects: breast pathology -- breast -- molecular genetics; Pathology -- Periodicals; Pathology, Molecular -- Periodicals; 616.0705
• DOI: 10.1136/jclinpath-2019-206208
• Languages: English
• ISSNs: 0021-9746

Abstract

Abstract : Fibroepithelial tumours are biphasic neoplasms of the breast comprising the common benign fibroadenomas and the less common phyllodes tumours (PTs), which have recurrent potential. PTs are classified into benign, borderline or malignant, based on five histopathological criteria, with malignant PTs having the highest metastatic capability. Accurate diagnosis can be challenging due to the subjective assessment of histopathological parameters. Fibroadenomas bear morphological similarities to benign PTs, while borderline and malignant PTs can sometimes be difficult to distinguish from other spindle cell tumours of the breast. From clonality studies to whole-genome sequencing, much research has been conducted to elucidate the molecular pathogenesis of fibroepithelial tumours, which, in turn, have allowed leveraging the findings for diagnostic applications, including grading of PTs. The most noteworthy discovery was of recurrent MED12 mutations in both fibroadenomas and PTs. Subsequent studies also uncovered relatively frequent genetic mutations in TERT promoter and RARA . A customised panel of 16 most frequently mutated genes in fibroepithelial tissues has been compiled previously and has contributed to resolving a few diagnostic dilemmas. This review will introduce the 16 genes and focus on the top three that are most frequently mutated in fibroepithelial tumours: MED12, TERT, and RARA .