External Beam Radiation Therapy for Amyloidosis of the Urinary Bladder

Amyloidosis is a condition characterized by the extracellular deposition of amyloid, a fibrillary substance consisting of low-molecular-weight protein subunits. Amyloidosis may present either as a systemic disorder or as a process isolated to a specific organ without systemic involvement.

Localized amyloidosis can occur in any tissue within the body. Primary bladder amyloidosis (PBA) is a rare disorder that presents with gross, painless hematuria that may be accompanied by lower urinary tract symptoms (LUTS). The computed tomography (CT) and cystoscopic findings of PBA can easily be confused with malignancy. The pathologic diagnosis of amyloidosis depends on affinity to Congo Red dye and apple-green birefringence under polarizing light microscopy.