Bilateral Limbal Keratin-Associated Amyloidosis

Area of Science:

• Ophthalmology
• Dermatology
• Biochemistry

Background:

• Conjunctival amyloidosis is typically associated with immunoglobulin light chain (AL) amyloid.
• Previous descriptions of cytokeratin-related amyloid involve immunohistochemical analysis of cutaneous and mucous membrane lesions.

Observation:

• The case involved bilateral limbal amyloid deposits.
• The conjunctival lesion in the right eye exhibited intraepithelial dyskeratotic cells leading to leukoplakia.
• Hereditary benign intraepithelial dyskeratosis was excluded in this patient.

Findings:

• Mass spectrometry identified the limbal amyloid deposits as keratin-related, specifically basal keratinocyte keratins 5 and 14.
• This represents the first documented instance of cytokeratin-related amyloid in ocular tissues.

Implications:

• This discovery expands the known spectrum of amyloidosis in ocular tissues.
• Highlights the utility of mass spectrometry in diagnosing rare amyloid subtypes.
• May necessitate re-evaluation of diagnostic approaches for conjunctival lesions.