What is Cystitis Cystica?
Cystitis cystica is a benign chronic inflammatory bladder condition characterized by cystic proliferations within the bladder wall, not an infectious process despite its misleading name. 1, 2
Pathophysiology and Microscopic Features
- The condition represents focal epithelial proliferation with cyst formation in the bladder mucosa, consisting of 2-3 layered epithelium with either tall columnar or flattened cells lining fluid-filled lumens 2
- Histologically, cystitis cystica lesions are tertiary lymphoid tissue with germinal centers that resemble follicular cystitis, indicating an organized immune response rather than simple inflammation 1
- The cyst walls contain cells with short microvilli, membrane-bound secretory granules, and are separated from underlying connective tissue by a basal lamina 2
- Adjacent urothelium often shows abnormal features including large intracellular vacuoles, Brunn's nests, lymphocyte infiltration, and disorganized architecture 2
Clinical Associations and Risk Factors
- Cystitis cystica strongly correlates with postmenopausal status (OR: 5.53), pelvic floor myofascial pain (OR: 6.82), and having ≥4 urinary tract infections in the past year (OR: 2.28) 1
- The condition predicts worse recurrent UTI outcomes, with shorter time to next urinary tract infection (HR: 1.54) 1
- It can rarely cause bladder outlet obstruction when located at the bladder neck 3
Clinical Presentation and Diagnosis
- Cystitis cystica is typically identified during cystoscopy performed for evaluation of recurrent UTIs or other bladder symptoms 1
- The condition affects approximately 38% of women with recurrent UTIs who undergo cystoscopy 1
- This is NOT interstitial cystitis/bladder pain syndrome (IC/BPS), which requires bladder/pelvic pain for at least 6 weeks with negative cultures 4, 5
Natural History and Treatment
- Most lesions (82%) demonstrate improvement or resolution over time with appropriate treatment of underlying conditions 1
- Intravesicular sodium hyaluronate therapy has shown efficacy in ameliorating bladder mucosal inflammation and cell proliferation by inhibiting the IL-6/JAK2/Stat3 signaling pathway 6
- When lesions recur or cause obstruction, transurethral resection may be necessary, though recurrence after resection can occur 3, 7
Important Clinical Distinctions
- The term "cystitis cystica" is a misnomer—it is not an infectious cystitis but rather a proliferative bladder condition (more accurately termed "cystosis") 8
- When associated with bladder tumors, these tend to be non-infiltrating papillary lesions with good prognosis 8
- The condition can masquerade as low-grade urothelial carcinoma on cystoscopy, requiring biopsy for definitive diagnosis 7
Clinical Implications
- Identifying cystitis cystica in recurrent UTI patients may inform future UTI risk stratification and guide tailored treatment strategies 1
- The presence of cystitis cystica should prompt evaluation for underlying pelvic floor dysfunction and consideration of postmenopausal status as contributing factors 1