Adenoid cystic carcinoma (ACC) arises most commonly in the salivary glands of the head and neck. Adenoid cystic carcinoma can also appear in the trachea, lacrimal gland (tear gland), and skin.
Adenoid cystic carcinoma is a slow-growing cancer, but it will generally recur and progress, metastasizing (spreading) to distant organs. It seldom spreads to nearby lymph nodes.
There are three major classifications for structural growth patterns: cribriform, tubular, and solid. Under a microscope, cribriform structures appear to have open spaces or small holes. In tubular structures, the cells appear to be arranged in the form of tubules. The solid structure, which is generally the most aggressive of the three, contains no cysts or liquid areas.