TY - JOUR T1 - Associations of epithelial c-kit expression in phyllodes tumours of the breast JF - Journal of Clinical Pathology JO - J Clin Pathol SP - 808 LP - 811 DO - 10.1136/jclinpath-2015-202921 VL - 68 IS - 10 AU - John Tawasil AU - Edna May L Go AU - Julia Y S Tsang AU - Yun-Bi Ni AU - Chun-Wai Ko AU - Gary M Tse Y1 - 2015/10/01 UR - http://jcp.bmj.com/content/68/10/808.abstract N2 - Background Mammary phyllodes tumours (PT) are rare biphasic neoplasms but have important clinical significance. Both epithelial and stromal components participate in PT development. Despite a number of studies on stromal c-kit in PT, little is known about the role of its epithelial expression.Objective To further evaluate the stromal and epithelial expression of c-kit in a cohort of patients with PT.Method and results Expression of c-kit in both epithelial and stromal components was examined and correlated with histological features in PT. Stromal c-kit expression was associated positively with stromal cellularity (median expression=10.0, 30.0 and 50.0 from mild to severe cellularity; p=0.019). Conversely, a significant negative trend between epithelial c-kit expression with stromal pleomorphism (median expression=55.0, 30.0 and 2.5 from mild to severe pleomorphism; p=0.043) and mitosis (median expression=70.0 and 20.0 for low and high mitosis respectively; p=0.003); and a trend of negative correlation with increased PT grade was found. Despite these reverse associations, epithelial and stromal c-kit expressions were positively correlated with each other. Notably, the correlation of stromal c-kit expression with malignant histological features appeared to be stronger in cases with low epithelial c-kit expression but not in those with high epithelial c-kit expression.Conclusions This study demonstrated the association of epithelial c-kit expression with stromal histological features and stromal c-kit. Interestingly, epithelial c-kit expression affected the strength of the correlation of stromal c-kit with these histological features. These findings provide further evidence of the interaction between the epithelial and stromal components in PT. ER -