Abstract
The term amyloidosis refers to a series of pathologies with abnormal folding of proteins, that have in common the formation of extracellular deposits of insoluble protein fibrils in organs and soft tissues. The fibrils present green apple birefringence after being dye with red Congo and observed with electronic microscopy. Up to 60 types of proteins have been identified in the amyloid deposits, that is why it is so important to perform immunohistochemical studies to identify the protein present in an amyloid fibril. The amyloidosis that occurs in the context of inflammatory or infectious chronic disease presents a protein called serum amyloid A. The case of a patient with chronic osteomyelitis that presents serum amyloid A amyloidosis is discussed.