Primary cutaneous amyloidosis of the auricular concha - case report

First Report of Bilateral External Auditory Canal Cochlin Aggregates (“Cochlinomas”) with Multifocal Amyloid-Like Deposits, Associated with Sensorineural Hearing Loss and a Novel Genetic Variant in COCH Encoding Cochlin

“…In diagnostic surgical pathology, Congo red-positive amorphous deposits with yellow and green birefringence under crossed polarization light microscopy elicits a provisional diagnosis of amyloidosis. While Congo red-positive amyloid deposits in the external ear have been reported as a form of primary cutaneous amyloidosis in the auricular concha [17], Congo red reactivity of cochlin protein has not been previously described in the published literature. Rarely, entities other than amyloid may be Congo red-positive, such as DNAJB9 protein in fibrillary glomerulonephritis [18].…”

Lichen Amyloidosis of the External Ear

“…Treatment options include topical keratolytic agents with mild to moderate topical corticosteroids and various physical modalities such as curettage and radiofrequency ablation. [ 5 ]…”

“…Differential diagnosis, when isolated conchal papules are present, includes discoid lupus erythematosus, adnexal neoplasms, and seborrheic keratosis. [ 5 ] However, the presence of multiple closely grouped keratotic papules in the concha with the absence of follicular plugging may be a useful clue. Through this report, we wish to increase awareness about this uncommon benign condition.…”