Pleomorphic Adenoma in the Auricle

Abstract

Pleomorphic adenoma (PA) is a rare tumor of the skin that may arise from either the apocrine or the eccrine glands. Only 4 cases of PA in the auricle have been reported. We experienced the case of a 40-year-old woman who had a slowly growing, nontender auricle mass for 3 years. Under a clinical diagnosis of an epidermal inclusion cyst, we performed a total excision of the tumor with the skin and with direct closure. No recurrence was found during the 18 months of postoperative follow-up. Histologic examination confirmed a diagnosis of PA. Hematoxylin-eosin stain showed tubules that were lined with 2 layers of epithelial cells. The stroma was composed of the myxoid and chondroid matrices. Immunohistochemical staining was positive for cytokeratin, epithelial membrane antigen, and gross cystic disease fluid protein, whereas it was negative for S-100 and carcinoembryonic antigen. These findings suggested that this tumor originated from the apocrine glands. Only a few cases of PA in the auricle have been reported in the literature, 2 of which occurred in the helical rim. Recurrence is rare if there is complete resection of the tumor along with the surrounding capsule. We report herein a rare case of PA that developed in the auricle.