Adenoid Cystic Carcinoma in Unusual Locations – Differential Diagnosis Difficulties

Adenoid Cystic Carcinoma (ACC) is an uncommon malignant salivary gland tumor, representing 1% of all malignant tumors of the oral and maxillofacial region and 22% of all salivary gland malignancies. Although in the majority of cases ACC manifests in the major salivary glands, in rare instances it can be found in locations such as the esophagus, larynx, trachea, lacrimal gland, breast, prostate, lungs, or auditory canal. These unusual locations of ACC often pose a diagnostic challenge to the clinician and are associated with poorer outcomes for patients as compared to those ACC of a more typical presentation. In this study we examined three cases of ACC, originating in the external auditory canal, larynx, and trachea, highlighting the hallmark features that may aid the clinician in their detection