Histopathologic and clinical comparison of recurrent and non-recurrent urethral stricture disease treated by reconstructive surgery

BACKGROUND: Urethral stricture is a relatively frequent problem often requiring multiple surgical interventions. The objective of this study was to compare the clinicopathologic features of urethral resections from patients who underwent open end-to-end anastomotic urethroplasty and later recurred compared to those who did not. METHODS: A retrospective review of the pathology files identified 36 consecutive patients who underwent urethroplasty. The histopathological analysis included evaluation of the inflammatory infiltrate based on the predominant (>50%) cell type: lymphocyte-rich, neutrophil-rich, plasma cell-rich, and mixed; length and thickness of the fibrous plaque; and the cellularity of the fibrous plaque: cellular (>40 stroma nuclei/HPF) or paucicellular (<40 stroma nuclei/high power field). RESULTS: Ten (28%) patients recurred, and 26 (72%) did not. There was no significant difference between recurrent and non-recurrent cases in age, race, comorbidities, location of the stricture, and etiology. All patients with recurrent strictures showed dense paucicellular fibrotic plaques (10/10; 100%), while this was seen in 14/26 (53.8%) non-recurrent cases (P=0.01). Only one patient with cellular fibrosis showed recurrence during follow-up. The log-rank test shows that time to recurrence is significantly shorter in patients with paucicellular fibrosis compared to those with cellular fibrosis (P=0.036). The inflammation consisted of a mixed population of CD3(+) T-lymphocytes, CD20(+) B-lymphocytes, and CD68(+) histiocytes, and there was no difference in the composition of the inflammation between groups. All cases with plasma cell-rich infiltrate showed normal IgG4:IgG. CONCLUSIONS: Our study supports reporting cellularity of the fibrous plaque as a potential predictor of outcome in patients undergoing reconstructive urethroplasty. Patients with paucicellular fibrosis are at increased risk of recurrence.