Large Epithelial and Stromal Lesion of Breast: It’s Not Always Phyllodes!

Fibroepithelial lesions (FELs) of breast often pose a diagnostic challenge to pathologists.1 In this article, we share gross and microscopic findings of 3 large breast lesions with epithelial and spindle cell components: (1) a giant fibroadenoma (FA; Figure 1 [1A-C]), (2) a borderline phyllodes tumor (World Health Organization classification2; Figure 1 [2A-C]), and (3) a nodular pseudoangiomatous stromal hyperplasia (NPASH; Figure 1 [3A-C]). This brief report highlights histological overlap between NPASH and FELs, and describes morphological clues that can help pathologists in differentiating NPASH from FELs with PASH-like stroma