Ureter, Amyloidosis, H&E stain

Amyloidosis is caused by accumulation of proteins in the form of abnormal, insoluble fibres, known as amyloid fibrils, within the extracellular space in the tissues of the body. The fibrils, which measure 7-12 nm in diameter, form a beta-pleated sheet structure that confers birefringence after staining with Congo red. Amyloid deposits may be limited to a single organ - as in this case - (local amyloidosis) or they may be systemic and widely distributed to multiple tissues in the body. There are more than 20 different amyloidogenic proteins. AL amyloid is produced by clonal proliferation of plasma cells (multiple myeloma). AA amyloid is produced in diseases with chronic inflammation such as rheumatoid arthritis.

This slide shows H&E stain, see Related Content for Congo red stain.