Primary cutaneous amyloidosis of the auricular concha.

Several patterns of primary cutaneous amyloidosis are recognized; in this report of four cases, we define a new pattern in which the lesions are composed of small papules grouped on the concha of the ear. The lesions typically are not pruritic but slightly friable. They may be present on both ears. The patients do not have lesions of amyloidosis on other parts of the body and no known insult precedes the appearance of lesions. This entity appears to have been described previously as collagenous papules of the ear. Histochemical and electron microscopic methods allow us to confirm the amyloid nature of the substance. We believe this condition to be a variant of primary cutaneous amyloidosis, particularly because monoclonal antikeratin antibody EKH4, which has been positive in lichenoid, macular, and skin epithelial tumor-associated amyloidoses, was positive in our cases.