An Extremely Rare Case of Squamous Cell Carcinoma Following Treatment for External Auditory Canal Papilloma

The case is of a 60-year-old woman with a history of radiotherapy for parotid adenoid cystic carcinoma. Twenty years after irradiation, a papilloma developed in the left external auditory canal. Nine years after excision of the papilloma, a squamous cell carcinoma developed in the same region. This is a rare case of squamous cell carcinoma following treatment for a papilloma and is considered radiation-induced cancer. Because re-irradiation is not possible as a treatment for radiation-induced cancer, it is necessary to diagnose the cancer early so that curative resection is possible. Multiple biopsies should be considered when malignancy is suspected because a single biopsy may not be sufficient to diagnose an auditory canal tumor.