URINARY BLADDER PATHOLOGY
Congenital anomalies of the bladder. Exstrophy of the bladder is a developmental failure of the formation of the abdominal wall and bladder which leaves the blad-der open at the body surface. Urachal cyst remnants may permit drainage of urine from a newborn’s umbilicus, and may also be a cause of bladder adenocarcinoma.
Cystitis. The etiology of cystitis varies, with important causes including organ-isms, notably from fecal flora (Escherichia coli, Proteus, Klebsiella, Enterobacter); radiation cystitis (may follow radiation therapy); and chemotherapy agents such as cyclophosphamide (hemorrhagic cystitis).
Clinically, it affects females far more than males. Symptoms include frequency, urgency, dysuria, and suprapubic pain; systemic signs such as fever and malaise are uncommon. Predisposing factors include benign prostatic hypertrophy, bladder calculi, and cystocele.
Malakoplakia is a bladder inflammatory pattern associated with a defect in macro-phage function. The cause is unknown. Macrophages contain Michaelis-Gutmann bodies, laminated basophilic structures.
Urinary bladder tumors are most commonly due to transitional cell carcinoma. There is an increasing incidence of urinary bladder tumors; males are affected more than females, and peak incidence is age 40-60. Risk factors include:
• Cigarette smoking and occupational exposure to azo dye production (transi-tional cell carcinoma) (both due to 2-naphthylamine)
• Chronic bladder infection with Schistosoma haemotobium (squamous cell car-cinoma) (Africa including Egypt and the Middle East)
Bladder cancer usually presents with painless hematuria, but it may also cause dys-uria, urgency, frequency, hydronephrosis, and pyelonephritis.
Prognosis of bladder cancer depends on the tumor grade and stage. There is a high incidence of recurrence.
Precursors of invasive transitional cell carcinoma can arise from a flat or papil-lary lesion.
• Carcinoma in situ (CIS) is a high-grade lesion with cytologic atypia in the full thickness of the epithelium. It is frequently multifocal. In 50-75% of untreated cases, it progresses to invasive cancer.
• Papillary precursors to invasive carcinoma include papilloma ⇒ papillary urothelial neoplasia of low malignant potential ⇒ low-grade urothelial carcinoma ⇒ high-grade urothelial carcinoma.
Other bladder tumors include papillomas, adenocarcinoma, and embryonal rhab-domyosarcoma.
Miscellaneous bladder conditions
• Acquired diverticuli can complicate urinary tract outlet obstruction due to benign prostatic hyperplasia or other causes.
• Cystocele is the term used for prolapse of the bladder into the vagina. It is common in middle-aged to elderly women.
• Cystitis cystica et glandularis causes formation of small cysts and glands in the bladder mucosa related to chronic inflammation. It is associated with an increased risk of adenocarcinoma.