The central granular cell odontogenic tumor: report of 5 new cases.

This article reports 5 previously unreported cases of central granular cell odontogenic tumor and compares them with 25 cases from the literature. This lesion appears to be an uncommon benign odontogenic neoplasm of uncertain histogenesis; it occurs over a wide age range with a predilection for the mandibular premolar-molar region. Radiographically, it typically manifests as a well-defined unicystic or multilocular radiolucency, although it can be a mixed-density lesion as well. In our series, there was a narrow spectrum of histologic features consisting of fibrous tissue of altering density and cellularity with plentiful numbers of large eosinophilic granular cells, variable amounts of "inactive-appearing" odontogenic epithelium, and the variable presence of calcified tissue resembling cementum or dystrophic calcifications. The ultrastructural and immunohistochemical findings in this study support a mesenchymal origin for the granular cells. One recurrence was documented in the current series in contrast to no recurrences in the literature.