Unicystic ameloblastoma. Unicystic ameloblastoma is an ameloblastoma that is entirely cystic and whose cyst lining is composed of traditional ameloblastomatous components: a palisaded basal layer with reverse nuclear polarity and an overlying stellate reticulum. In this example, squamous change is seen, a common finding in ameloblastoma. Careful examination of such a cystic lesion is required as separation from cystic ameloblastoma is critical from a treatment perspective. Unicystic ameloblastoma has no invasion or penetration of the cyst wall by the ameloblastomatous cystic lining while the similar sounding tumor, cystic ameloblastoma, has an ameloblastomatous cystic lining which also penetrates the wall of the cyst. The former can be treated with thorough curettage of the cyst lining with chemical cautery while the latter could require surgical therapy with excision of margins 1 cm from the radiographic border of the lesion, the same therapy as for ameloblastoma with no cystic change.