Avoiding misdiagnosis in ceruminous gland tumours.

Ceruminous gland tumours are infrequent lesions of the external auditory canal (EAC). Controversy still exists about nomenclature, classification, tissue of origin, and accurate diagnosis of these tumours. We present three cases of ceruminous gland tumours, including benign eccrine cylindroma, ceruminous adenoma, and adenoid cystic carcinoma. Superficial biopsy led to an initial erroneous diagnosis of adenocarcinoma in the latter. All cases were positive for cytokeratin and S-100 protein, supporting a ceruminous gland origin. The benign eccrine cylindroma should be included in the ceruminous gland tumour classification. A wide excisional biopsy should be performed in every EAC lesion. The terms 'ceruminoma' and 'cylindroma' should be avoided.