Survival Impact of Variant Histology Diagnosis in Upper Tract Urothelial Carcinoma.

Variant histology UTUC is associated with advanced stage and poor survival, and could serve as a useful biomarker for high-risk disease when pathological stage is unknown. However, the inferior CSS and OS with variant histology can be explained by the higher tumor stage on nephroureterectomy. Thus, finding variant histology on surgical pathology does not provide additional prognostic information beyond stage.