Eosinophilic cystitis. A study of 16 cases

Area of Science:

• Urology
• Pathology
• Allergy

Background:

• Eosinophilic cystitis (EC) is a rare bladder inflammation characterized by eosinophil infiltration.
• Previous reports show varied demographics and associations, suggesting different underlying causes.
• Distinguishing EC from other bladder conditions, including cancer, is crucial for appropriate management.

Purpose of the Study:

• To describe a series of 16 cases of eosinophilic cystitis.
• To compare these cases with previously reported English-language series.
• To investigate potential predisposing factors, diagnostic challenges, and related conditions.

Main Methods:

• Retrospective analysis of 16 patient cases with eosinophilic cystitis.
• Comparison of clinical and pathological findings with 21 previously reported cases.
• Histopathological examination including Giemsa stain for eosinophils and trichrome stain for fibrosis.

Main Results:

• The authors' series predominantly featured older men with co-existing bladder/prostate conditions.
• In contrast, reported English cases were mainly women and children with allergies and eosinophilia.
• Bladder injury and allergic disorders appear to be key predisposing factors for EC.
• Clinical and pathological misdiagnosis, particularly as bladder carcinoma or chronic inflammation, was common.
• Muscle necrosis and fibrosis were significant findings, sometimes mimicking mucosal changes.
• Giemsa and trichrome stains proved valuable for diagnosis.

Conclusions:

• Eosinophilic cystitis likely arises from either bladder injury or allergic predisposition.
• The bladder-injury type may be underdiagnosed due to its presentation mimicking other conditions.
• EC shares pathological links with allergic cystitis and interstitial cystitis, highlighting the role of inflammation and allergy.