Histopathology of Anterior Urethral Strictures: Toward a Better Understanding of Stricture Pathophysiology

Purpose: Histopathology can provide insights into disease mechanisms but to date it has been poorly described for urethral stricture. The purpose of this study was to comprehensively describe histopathological findings of stricture specimens obtained at the time of anterior urethroplasty. Materials and Methods: All pathological specimens of men who underwent anterior urethroplasty of urethral stricture disease from 2010 to 2017 at a single institution were rereviewed by a single blinded pathologist directed to rule out lichen sclerosus and then describe inflammatory cell type and severity when present. Cohorts comprising strictures with no inflammation, minimal to mild inflammation or moderate to severe inflammation were developed and stricture, patient and surgical outcome characteristics were compared. Results: Histopathology slides from 100 anterior urethroplasty cases were reviewed. Two or more lichen sclerosus characteristics were present in 21% of specimens and 44% of specimens showed chronic inflammation, which was minimal in 20%, mild in 39%, moderate in 39% and severe in 2%. Lymphocytes in 86% of specimens and plasma cells in 12% were the predominant cell types. Patients with inflammatory stricture reported worse overall health. Inflammation was largely absent from isolated bulbomembranous strictures (9%) and more common in lichen sclerosus strictures (100%). The 11% overall failure rate was not affected by the presence (7%) or absence (14%) of inflammation. Conclusions: Chronic inflammation is prevalent in a significant percent of urethral stricture disease specimens. Associations with worse overall health suggest systemic mediators. Absent inflammation in bulbomembranous strictures suggests a unique pathophysiology in this region. The presence of inflammation did not affect surgical outcomes at mid-term followup.