Bladder paragangliomas: a pictorial review

Area of Science:

• Urology
• Oncology
• Radiology

Background:

• Bladder paragangliomas (bPGL) are rare neuroendocrine tumors originating from sympathetic paraganglia in the bladder wall.
• They can be submucosal, intramural, or subserosal, impacting visibility during cystoscopy.
• Tumor size and complexity vary, with larger bPGLs exhibiting neovascularity and necrosis.

Purpose of the Study:

• To review the diagnostic imaging modalities for bladder paragangliomas.
• To discuss the role of imaging in surgical planning and treatment selection for bPGL.
• To highlight the importance of genetic screening and lifelong surveillance in bPGL patients.

Main Methods:

• Review of imaging characteristics of bPGL on ultrasound, MRI, CT, and nuclear medicine.
• Discussion of the utility of 68Ga-DOTATATE PET/CT and 123I-mIBG SPECT/CT in diagnosis and treatment planning.
• Emphasis on the genetic basis of bPGL and recommended screening protocols.

Main Results:

• Ultrasound shows increased color Doppler signal; MRI offers superior soft tissue resolution for localization.
• Restricted diffusion and avid contrast enhancement on MRI help differentiate bPGL from leiomyomas.
• Nuclear medicine, particularly 68Ga-DOTATATE PET/CT, is highly specific for detecting bPGL and metastases.

Conclusions:

• Imaging is essential for accurate diagnosis, surgical planning, and treatment of bladder paragangliomas.
• Advanced imaging techniques like PET/CT are vital for assessing treatment suitability, especially for advanced disease.
• Germline mutations are common, necessitating lifelong screening for associated conditions.