Unicystic ameloblastoma, luminal type. The neoplastic epithelium is confined to the luminal surface of the cyst i.e. the lesion consists of a simple unilocular cyst with a fibrous wall and lined partially or completely by multiple layers of ameloblastic epithelium. The basal portion of the lining epithelium is tall columnar or cuboidal with peripheral palisading and reverse polarity (nuclei oriented away from the basement membrane). The peripheral portion (towards the luminal aspect) is composed of loosely cohesive cells resembling stellate reticulum. Image courtesy of: @reportesvillarroel, Caracas, Venezuela.