Figure 3From: Oral involvement in a case of AA amyloidosis: a case report Histopathologic examination findings: the Congo red method was used to detect amyloid in tissue sections. Amyloid was identified as the AA type on immunohistochemical testing with the use of monoclonal antibodies specific to SAA. (A) Hematoxylin and eosin staining of the biopsy specimen shows homogen, eosinophilic material (×20, hemotoxylin and eosin). (B) The amorphous extra-cellular material stains positively with Congo red (×2.5, Congo red). (C) This Congo red-positive material appears apple-green when viewed under polarized light (×20 Congo red-positive material appears apple-green when viewed under polarized light). (D) Extra-cellular and peri-vascular deposits of amyloid reveal positive immunoreactivity with an antibody against amyloid A (×40).Back to article page