Invasive urothelial carcinoma: Subtypes and divergent differentiation

Abstract

Invasive urothelial carcinoma is the most frequent type of bladder cancer and may occur in pure or classical form or with the presence of variant or subtype histology and/or evidence of divergent morphology such as squamous, glandular, or trophoblastic differentiation. Increasingly, it is recognized that certain subtypes impact patient prognosis and outcome hence the need to correctly recognize and document their presence. Certain subtypes and divergent features correlate with the emerging molecular bladder cancer subtypes, which can also influence patient management decisions. The pathologist therefore plays a crucial role in providing clinically relevant information, mostly derived from hematoxylin and eosin slides, which will guide urologists and oncologists in terms of risk stratification and treatment planning.