Solitary primary amyloidosis of urinary bladder. Light and electron microscopic study

A fifty-four-year-old white woman with a history of episodic gross hematuria was diagnosed as having solitary primary amyloidosis of the urinary bladder involving a large segment of the dome and anterior wall. A segmental resection of the bladder was performed with good results. Electron microscopic examination of the lesion revealed evidence to indicate that amyloid in this case was produced by the fibroblasts within the lamina propria of the bladder. The mode of amyloidogenesis is identical to that noted in some of the previously published electron microscopic studies on localized amyloidosis of skin. Solitary primary amyloidosis of the urinary bladder is a rare lesion with only 46 cases having been previously reported in the literature.