Differential diagnosis of bladder masses and thickening

Abstract

Following the lecture, the attendee should be knowledgeable about the layers of the bladder and how pathology of the bladder manifests radiologically. The attendee should have obtained knowledge about the imaging features and optimal imaging modalities for the spectrum of bladder neoplasms as well as some of the more common inflammatory, idiopathic and miscellaneous disorders which the radiologist may encounter in practice. Specific imaging findings of these processes which may allow the radiologist to be more specific in their interpretation will be covered. In addition, the attendee will become familiar with the imaging findings of extrinsic masses involving the bladder. Many pathologic lesions have overlapping radiologic appearances but there are sorne patterns which may narrow the differential diagnosis and allow the radiologist to be more specific. For neoplasms, these include the papillary and multifocal appearance of urothelial carcinoma, the grape like appearance of botryoid rhabdomyosarcoma, the target sign of plexiform neurofibroma, the specificity of MIBG for paragangliomas, and the location and appearance of leiomyomas, and urachal adenocarcinoma. For non neoplastic disorders, radiologists should look for the characteristic MR features of bladder endometriosis and for the extravesical findings which allow the diagnosis of extrinsic involvement by adjacent bowel, prostate or gynecologic processes. The bladder has a limited response to a variety of irritants and chemicals, with many pathologic processes resulting in a similar end result of either a mass or wall thickening. This lecture will review the clinical and imaging features of the most common bladder neoplasms with particular reference to distinguishing features. Non neoplastic disorders including inflammatory and idiopathic processes may have clinical and imaging features in common with neoplasms. These will also be discussed.