Light Chain Amyloidosis Presenting as Bilateral External Auditory Canal Obstructing Masses.

Abstract

: A morbidly-obese 57-year-old diabetic and hypertensive man with chronic kidney disease, diastolic heart failure, and bilateral hearing loss was found to have soft tissue masses/densities in the lateral aspect of both auditory canals on local examination and on imaging. He underwent biopsies of both ear canal masses and histologic examination revealed amyloid deposits in the dermis. These deposits were confirmed as AL (amyloid light chain) kappa-type amyloid by laser mass spectrometry. A systemic work-up showed plasma cell dyscrasia with 9% kappa light chain restricted plasma cells in the bone marrow as well as amyloid deposits on a kidney biopsy.Involvement of the external auditory canals is a rare manifestation of systemic amyloidosis with only 13 cases reported so far, of which four cases had bilateral external auditory canal involvement, associated with multiple myeloma. Interpretation of small biopsies can be challenging especially with early, scant amyloid deposits, but a sufficient biopsy to type amyloid by immunohistochemistry or laser mass spectrometry is imperative for further management. Early diagnosis and treatment of systemic light chain amyloidosis translates to better patient outcomes, while delay in management could lead to dismal prognosis.