This effect is localized to ceruminous gland membranes. Examples of exocrine glands include sweat, salivary, mammary, ceruminous, lacrimal, sebaceous, prostate and mucous. In this location, they are referred to as ceruminous glands. The benign tumors include ceruminous adenoma, ceruminous pleomorphic adenoma, and ceruminous syringocystadenoma papilliferum. The malignant tumors include ceruminous adenocarcinoma, adenoid cystic carcinoma, and mucoepidermoid carcinoma. Ceruminous adenocarcinoma is a malignant neoplasm derived from ceruminous glands of the external auditory canal. The most common tumor type is ceruminous adenoid cystic carcinoma and ceruminous adenocarcinoma, NOS. Ceruminous adenoma are rare tumors, accounting for less than 1% of all external ear tumors.