Beca F, Krings G, Chen YY, et al. - In this study, the clinical, pathologic, and genomic features of ten cases of PMAS, including one patient with the bilateral disease were explored. Investigators distinguished recurrent genomic alterations in KDR (70%), PIK3CA/PIK3R1 (70%), and PTPRB (30%), each at higher frequencies than reported in AS across all sites. They did not identify MYC or TP53 aberrations in this series. It was reported that immunohistochemistry for VEGFR2 was unable to discriminate between KDR-mutant tumors and benign vascular lesions of the breast. The data indicate, in PMAS, the underrecognized frequency of KDR and PIK3CA mutation, and a significant subset with hypermutation, implying pathogenesis distinct from other AS.