Urinary Bladder Masses, Rare Subtypes, and Masslike Lesions: Radiologic-Pathologic Correlation.

Area of Science:

• Urologic pathology
• Diagnostic imaging
• Oncology

Background:

• Urinary bladder masses are common, with 95% originating from the epithelial layer.
• Neoplastic invasion depth is assessed via multimodality imaging, with MRI-based Vesical Imaging Reporting and Data System aiding staging.
• Diverse pathologic entities arise from the bladder's multiple layers and cell lineages.

Purpose of the Study:

• To review the diverse range of urinary bladder masses.
• To highlight the importance of histopathologic assessment for accurate classification.
• To discuss challenges in differentiating benign, malignant, and nonneoplastic bladder entities.

Main Methods:

• Review of current literature on urinary bladder masses.
• Discussion of imaging modalities, including MRI Vesical Imaging Reporting and Data System.
• Emphasis on histopathologic classification of bladder tumors.

Main Results:

• Urothelial carcinoma is the most common malignancy in the US.
• Other malignancies include squamous cell carcinoma, adenocarcinoma, melanoma, and neuroendocrine tumors.
• Atypical benign masses can mimic malignancy, necessitating careful pathologic evaluation.

Conclusions:

• Pathologic assessment is the gold standard for classifying urinary bladder masses.
• Distinguishing benign from malignant bladder masses is challenging, even with advanced imaging.
• Understanding the spectrum of bladder masses, including variants and mimics, is crucial for patient care.