Related Experiment Video
Updated: Feb 8, 2026

Genetic Analysis of Hereditary Transthyretin Ala97Ser Related Amyloidosis
Published on: June 9, 2018
Light Chain Amyloidosis Presenting as Bilateral External Auditory Canal Obstructing Masses
Shenon Sethi1, Agne Paner2, Tochukwu Okwuosa3
1Department of Pathology.
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.
Related Concept Videos
Mass Spectrometry: Long-Chain Alkane Fragmentation
Electron Transport Chains
The ETC is comprised of...
Work Done on a System by External Force
In the presence of a non-conservative opposing force, like friction, some part of the work done...
The Auditory Ossicles
The aptly named stapes look very much like a stirrup. The three ossicles are unique to mammals, and each plays a role in...
Auditory Pathway
When viewed cross-sectionally, the cochlea reveals the scala vestibuli and scala tympani flanking...
Auditory Perception

