Discussion

Abstract

The ameloblastoma is the quintessential odontogenic tumor. Histologically and behaviorally, this jaw neoplasm resembles the basal cell carcinoma of skin. The aggressive nature of ameloblastomas has been well documented in the literature, and the variations that this tumor may assume histologically have not been found to correlate with prognosis nor does the histology govern therapy. An exception emerged with the report by Robinson and Martinez, 1 Robinson L Martinez MG Unicystic ameloblastoma: A prognostically distinct entity. Cancer. 1977; 40: 2278 Crossref PubMed Scopus (246) Google Scholar who first described a subset of ameloblastoma that is cystic in nature and tends to arise during the second decade. This so-called unicystic (or simply cystic) ameloblastoma (UCA) was segregated from the “conventional” or “solid” or “invasive” type of ameloblastoma based on clinical, radiographic, gross surgical, and histologic criteria. The invasive form is typically encountered in midadult life, tends to be multilocular, is solid or only microcystic on gross examination, grows in an invasive fashion characterized by solid or microcystic nests of odontogenic epithelium that resemble the ectodermal portion of the cap stage tooth germ, and frequently recurs after surgical curettage. Alternatively, the unicystic variant arises during the teens; is unilocular or occasionally multilocular, and usually pericoronal (typically mandibular third molar association); is grossly cystic with some tumors exhibiting an intraluminal tumor mass; shows a cyst lined by basal ameloblastic epithelium and upper strata stellate reticulum; and, on follow-up studies, the rate of recurrence after curettage is low.