Histological And Immunohistochemical Comparison Of Secondary Post-traumatic Amyloidosis And Polymorphic Amyloid Degeneration Of The Cornea

Abstract

Purpose: : To present the clinicopathological findings in the cornea from eight patients with localized, degenerative corneal amyloidosis. We compared the histopathological and immunohistochemical features in four cases of localized, corneal amyloidosis following perforating wounds, and in four cases of polymorphic amyloid degeneration utilizing immunohistochemical stains of amyloid protein precursors.

Methods: : Retrospective case series with a study group of eight patients found to have localized, degenerative corneal amyloidosis. The clinical history and histopathological features of all the corneal specimens were reviewed. The nature of the amyloid protein in these conditions was assessed by immunohistochemical stains for amyloid AP, AA, and AL (kappa and lambda light chains). Two cases of lattice corneal dystrophy, type 1, were used as controls to compare with the findings in these two degenerative conditions.

Results: : We found that a prominent break in Bowman’s layer was evident in all four cases of post-traumatic amyloidosis. Histopathologically, the amyloid had an amorphous, pale, eosinophilic appearance within the corneal stroma on hematoxilyn and eosin staining and showed positive Congo red staining with apple-green birefringence under polarized light. We found positive staining in the amyloid deposits only for amyloid AP with negative staining for amyloid AA and AL.

Conclusions: : There are few reports in the reviewed English literature of the histopathologic and immunohistochemical findings in amyloid deposition post-corneal trauma or in polymorphic amyloid degeneration. We identified the nature of the amyloid deposits with histological characterization of these two uncommonly reported corneal disorders. The amyloid proteins deposited in secondary post-traumatic amyloidosis and in polymorphic amyloid degeneration of the cornea showed only amyloid AP and do not represent amyloid AA or AL.

Keywords: pathology: human • immunohistochemistry • cornea: stroma and keratocytes