Clinical and histological characteristics of melanocytic nevus in external auditory canals and auricles.

Nevi, which consist of nevus cells arising from external auditory canals (EACs) and auricles, are rare and their characteristics are not thoroughly understood. The purpose of this study was to analyze the clinicopathological characteristics of melanocytic nevus (MN) in EACs and auricles. Medical records were reviewed in 35 cases with junctional, compound and intradermal nevi treated in Ajou University Hospital, Korea between 2001 and 2011. Patient demographic, location, shape, and diameter of nevi, and pathologic results were analyzed according to the location, EACs (23 cases) and auricles (12 cases). Female predominance was noted in both EAC (60.9 %, 14 cases) and auricular (75 %, 9 cases) nevi. The mean age of EAC nevi (37.1 years) was younger than that of auricular nevi (42.2 years). The chief complaint was a symptomless mass in both groups, mostly in dome-like gross appearances. The mean diameter of EAC and auricular nevi was 9.6 (3-16) mm and 12.2 (3-25) mm, respectively. Histological findings chiefly presented intradermal nevi in EACs (78.3 %) and auricles (83.3 %) which showed preference to older patients, in contrast to the compound type. All nevi including five cases with skin grafts were completely excised without any recurrence within the follow-up period (average 5.3 months). A possible dysplastic nevus was detected in only one case. All MNs in EACs or auricles reveal similar characteristics. Early and complete excision is recommended to avoid skin graft, functional problems, and the risk of malignant melanoma.