Chapter 21: The Lower Urinary Tract and Male Genital System

The Lower Urinary Tract and Male Genital System begins with the ureters and bladder, detailing developmental anomalies such as ureteropelvic junction obstruction and bladder exstrophy while explaining how chronic irritation or infection leads to various forms of cystitis, including the distinctive macrophage-rich malakoplakia and the symptomatic challenges of interstitial cystitis. A significant portion of the text is dedicated to urothelial neoplasms, highlighting the distinct molecular pathways of non-invasive papillary tumors versus muscle-invasive cancers and identifying critical environmental risk factors such as tobacco use and industrial chemical exposure. Moving to the male genital tract, the discussion examines penile pathologies ranging from congenital defects like hypospadias to the oncogenic role of high-risk human papillomavirus (HPV) in squamous cell carcinoma development. Testicular health is addressed through the clinical urgency of spermatic cord torsion and the diverse landscape of germ cell tumors, including seminomas and nonseminomatous variants, which are traced back to their origins in germ cell neoplasia in situ. Finally, the chapter provides an extensive overview of the prostate gland, contrasting the high prevalence of benign prostatic hyperplasia (BPH) and its dihydrotestosterone-driven pathogenesis with the significant morbidity associated with prostatic adenocarcinoma. It outlines the current standards for oncological stratification using the Gleason grading system and evaluates the utility and limitations of prostate-specific antigen (PSA) testing in diagnostic screening and long-term patient management.