Basal cell carcinomas of the auricular region: a study of 23 cases

Basal cell carcinomas (BCCs) of the auricular region are not frequently reported, especially in the Japanese literature. Predisposing conditions such as sun exposure or frostbite are possibly involved in their development. In this study, we report our cases of auricular BCCs, discussing the obtained results, the possible significance of predisposing conditions, and the correlation with the histologic subtypes involved. Among 1094 patients with BCCs, auricular tumors were observed in 23 patients (2.1%), 4 women and 19 men. All of them were present on the external sun-exposed auricular side. Histologic patterns were nodular and micronodular (13 cases) and infiltrative (10 cases). No differences were observed between sexes. The relative degree of elastosis was higher in men than in women. Frostbite was recorded in 4 cases. The ear is an anatomical region that is heavily exposed to sun-light and equally prone to frostbite. Our data showed that all the lesions were located on the auricular region more or less exposed to sunlight. There was a recorded previous history of predisposing factors in most cases, and the high degree of elastosis suggests the involvement of these predisposing factors. Moreover, the high prevalence of infiltrative subtypes observed in our survey suggests a possible correlation between some histologic subtypes, sun-exposure, and frostbite. The differences between the relatively high number of auricular BCCs reported in the literature in contrast with the Japanese observations suggest the involvement of social or local conditions.