A rare case of adenoid cystic carcinoma of the ceruminous glands of the external auditory canal

This report examines a case of ceruminous gland adenoid cystic carcinoma, which is a rare malignancy of the external auditory canal that can mimic or present with concurrent chronic otitis externa or simple cerumen impaction. This patient was a 33-year-old who presented with right-sided otalgia and conductive hearing loss due to an enlarging right external auditory canal mass. The initial excision and histopathology of a fragmented sample revealed ceruminous gland adenoid cystic carcinoma without perineural invasion. Due to the nature of the sample, clear margins were not established. Subsequently, the tumour remanifested within the surgical bed four months later. A second wide local excision revealed Grade 2 adenoid cystic carcinoma on immunohistochemistry (CK7+, p63+, Ki-67 50%), with clear margins. Following MDT review, a canal wall down mastoidectomy was performed with facial nerve monitoring. The final histology showed no residual tumour, and CT thorax abdomen and pelvis did not reveal any metastasis. Currently, the patient is awaiting adjuvant intensity-modulated radiotherapy. This case highlights the need for high degree of suspicion of any ear canal granulation as well as locally recurrent behaviour of ceruminous ACC and underscores the importance of long-term multidisciplinary surveillance.