Han L, Gallan AJ, Steinberg GD, et al. - This study was attempted to define the histological features of genomically classified bladder cancers more extensively to tumors in radical cystectomy (RC) specimens. Applying the BASE47 genomic classifier, 48 bladder cancers submitted to The Cancer Genome Atlas (TCGA) were categorized into luminal subtype (LS) (14 cases), basal subtype (BS) (18 cases), and claudin-low subtype (CLS) (16 cases), and TCGA samples and the corresponding RC specimens were histologically evaluated. The results of this study demonstrate that histologic features associated with aggressiveness (eg, marked pleomorphism, high proliferation, and sarcomatoid change) are enriched in CLS tumors, correlating with its known poorer outcome that may provide hints in their microscopic distinction. The findings revealed that features more correlated with BS than with LS tumors (eg, squamous, marked pleomorphism, and sarcomatoid change) are also distinguished or enhanced in CLS tumors, supporting the genomic findings implying CLS tumor as a hyperbasal form of BS tumor.