The aesthetic and oncological challenges in the management of an atypical nodular hidradenoma of the pinna.

Nodular hidradenomas are benign adenomatous tumours of sweat gland origin, which commonly arise from the skin of the head, neck and extremities. Some of these benign appearing lesions exhibit aggressive clinical behaviour with rapid growth, pigmentation and ulceration. These tumors are designated as "atypical nodular hidradenomas" and are known to histologically possess some focal atypical features i.e. nuclear pleomorphism, focal necrosis or prominent mitotic activity. Nodular hidradenomas involving the pinna are rare and to the best of our knowledge there have been no prior reports in the English language literature. We describe a unique case of a 45-year-old woman with an atypical nodular hidradenoma of the left pinna and discuss the aesthetic and the oncological issues pertaining to the reconstruction of the pinna.