Upper tract urothelial carcinoma (UTUC) with variant histology is associated with aggressive features such as advanced stage, lower survival, and higher recurrence after surgery, according to investigators.
In a review of 115 high-grade UTUC cases published in Virchows Archiv, Antonio Lopez-Beltran, MD, PhD, of the University of Cordoba in Spain, and colleagues found that variant histology is typically observed in patients with high pathologic stage (82% pT2-pT4) patients and is associated with lower survival rates (46% vs 36% of conventional UTUC patients died of disease; median survival: 31 months). Variant histology also significantly predicts worse recurrence-free survival.
Of the 115 cases, variant histology was found in 39 (34%). It comprised urothelial carcinoma with 1 (23%), 2 (3%), or 3 or more variants (3%) as well as pure variant histology (4%). Common variants (alone or in combination) included, in descending order, squamous divergent differentiation (7%), sarcomatoid (6%), glandular (4%), and 3% each of micropapillary, diffuse-plasmacytoid, inverted growth, clear cell glycogenic, or lipid-rich variant. The pseudo-angiosarcomatous variant was observed in 2%, and 1% each of nested, giant-cell, lymphoepithelioma-like, small-cell, trophoblastic, rhabdoid, microcystic, lymphoid-rich stroma, or myxoid stroma/chordoid. In addition, the investigators identified loss of mismatch repair protein expression in 1 case with inverted growth variant.
According to Dr Lopez-Beltran’s team, “the current study shows that upper tract urothelial carcinoma with variant histology harbored aggressive biologic features in concordance with previous studies and, therefore, supports reporting the presence (and extension) of variant histology as part of the final pathology report in patients with upper tract urothelial carcinoma.”
Rolim I, Henriques V, Rolim N, et al. Clinicopathologic analysis of upper urinary tract carcinoma with variant histology [published online January 16, 2020]. Virchows Archiv. doi: 10.1007/s00428-020-02745-4