Histopathological Spectrum Of Lesions In The Urinary Bladder: A Retrospective Study

Abstract

Introduction: The urinary bladder is susceptible to a broad spectrum of non-neoplastic and neoplastic conditions, which often overlap both clinically and radiologically. Histopathologically, these lesions display varied morphological features, with certain benign conditions closely mimicking neoplasms, necessitating the importance of meticulous histopathological evaluation. While non-neoplastic conditions impact the quality of life, malignant neoplasms present life-threatening implications. Comprehensive histopathological evaluation, integrated with clinical and radiological findings and careful distinction of potential mimickers, forms the cornerstone of accurate diagnosis and optimal patient management.

Objective: To study and classify the histopathological spectrum of urinary bladder lesions into non-neoplastic and neoplastic categories, and to further classify neoplasms according to the WHO 2022 Histological Classification.

Methodology: This retrospective study was conducted from January 2018 to July 2024. Specimens included

bladder biopsies, transurethral resection of bladder tumors (TURBT), and cystectomies.

Results: This retrospective study examined 42 urinary bladder specimens, with 34 identified as neoplastic (81%) and 8 as non-neoplastic (19%). The male-to-female ratio was 2.5:1, and the most affected age group was 51–60 years, predominantly male. Hematuria was the most common symptom, followed by dysuria, increased urination frequency, and flank pain. Follicular cystitis was the leading non-neoplastic lesion (42.8%), followed by chronic cystitis (25%), with one case each of granulomatous cystitis, cystitis cystica et glandularis, and malakoplakia. Neoplastic lesions were predominantly non-invasive urothelial neoplasms (67.6%), particularly Papillary Urothelial Neoplasm of Low Malignant Potential (PUNLMP) (35.3%), followed by invasive urothelial neoplasms (26.4%), including 8 high-grade and 1 low-grade case, with muscularis propria invasion in 4 cases. Additionally, single cases of Squamous cell carcinoma and Embryonal rhabdomyosarcoma were observed.

Conclusion: A diverse array of lesions manifests within the bladder, with urothelial tumors notably prevailing, followed by cystitis. The gold standard for diagnosis is histopathological analysis of bladder specimens, which helps identify non-neoplastic and neoplastic conditions, grade and stage tumors, and classify neoplasms for treatment purposes.