Ceruminous adenocarcinoma

Ceruminous adenocarcinoma is a malignant neoplasm derived from ceruminous glands of the external auditory canal. This tumor is rare, with several names used in the past. Synonyms have included cylindroma, ceruminoma, ceruminous adenocarcinoma, not otherwise specified (NOS), ceruminous adenoid cystic carcinoma (ACC), and ceruminous mucoepidermoid carcinoma. Ceruminous adenocarcinoma is a malignant neoplasm derived from ceruminous glands of the external auditory canal. This tumor is rare, with several names used in the past. Synonyms have included cylindroma, ceruminoma, ceruminous adenocarcinoma, not otherwise specified (NOS), ceruminous adenoid cystic carcinoma (ACC), and ceruminous mucoepidermoid carcinoma. This tumor only affects the outer 1/3 to 1/2 of the external auditory canal as a primary site. If this area is not involved, the diagnosis should be questioned. The most common tumor type is ceruminous adenoid cystic carcinoma and ceruminous adenocarcinoma, NOS. Pain is the most common symptom, followed by either sensorineural or conductive hearing loss, tinnitus or drainage (discharge). A mass lesion may be present, but it is often slow growing. Imaging studies are used to define the extent of the tumor and to exclude direct extension from the parotid gland or nasopharynx. The imaging findings are usually non-specific, and cannot give a specific diagnosis. Tumors are polypoid, identified most often in the posterior canal. It is not uncommon to have ulceration of the surface squamous epithelium. Most tumors are about 1.5 cm in greatest dimension, a limitation of the anatomic site rather than of the tumor type itself. The tumors are separated into three main histologic or microscopic types: All of the tumors are infiltrative into the soft tissue, benign ceruminous glands, and/or bone. The tumor may expand into the overlying squamous surface epithelium, but it usually does not arise from the surface epithelium. The tumors are cellular, arranged in solid, cystic, cribriform, glandular, and single cell patterns. It is uncommon to see tumor necrosis, but when it is present, it is diagnostic of cancer. The same is true of perineural invasion. Nuclear pleomorphism is usually easily to identify, with the nuclei containing prominent nucleoli. There are usually increased mitotic figures, including atypical forms. There are usually areas of stromal fibrosis. Ceroid (cerumen or ear wax) is not seen in malignancies, although it is seen in benign tumors. The specific features of each tumor type can help with the separation into adenoid cystic carcinoma or mucoepidermoid types.