Primary cutaneous amyloidosis of the auricular concha: case report and review of published work.

A 70-year-old Japanese female developed tiny papules on her bilateral ears 2 years previously. A histological study of a biopsy specimen revealed that amorphous materials were present in the widened dermal papillae. Because these materials were positive for both Congo red and Dylon, we diagnosed the lesion as primary cutaneous amyloidosis of the auricular concha. Immunohistochemically, the amyloid substance stained positively with 34betaE12 (cytokeratin 1/5/10/14), suggesting that it had an epidermal origin. Seven reported cases of this unique disorder were also reviewed.