Clinical features:
(1) The typical patient is an adult over 40 years of age with actinic skin damage.
(2) The patient has a history of chronic trauma to the ear.
(3) The lesion is a solitary, tender, erythematous papule on the ear (most often helix) that becomes crusted.
(4) The lesion may measure 3-15 mm in diameter.
(5) The lesion does not heal despite therapy.
(6) The lesion may be painful if touched,
Histologic features:
(1) A developed lesion shows an area of ulceration with granulation tissue, chronic inflammation and fibrinoid degeneration in the dermis.
(2) Pseudoepitheliomatous hyperplasia is present in the surrounding skin.
(3) A piece of degenerated cartilage can be seen at the base of the lesion if the biopsy is taken deep enough.
Differential diagnosis:
(1) basal cell carcinoma or squamous cell carcinoma
(2) chronic granuloma
