Enucleation of a Rare Hybrid Odontogenic Lesion in the Anterior Maxilla of a 10-Year-Old Boy

Hybrid odontogenic lesions are a well-recognized phenomenon. They most often show features of various odontogenic neoplasms arising within cyst-like structures. The etiopathogenesis of hybrid odontogenic lesions is not well defined, however, the presence of numerous, closely approximated sources of pluripotent epithelial cells in the developing jaws is likely associated with their development. This case highlights an interesting mixed radiolucent and radiopaque, expansile cystic lesion with a follicular relationship to an unerupted tooth in a young child. Histologically, the lesion showed a combination of dentigerous cyst, calcifying odontogenic cyst and adenomatoid odontogenic tumor. Close radiographic proximity of the hybrid odontogenic lesion to a focal expansion of the gubernacular canal suggests that the adenomatoid odontogenic tumor portion of the hybrid lesion may have arisen directly from this structure, resulting in delayed eruption of the adjacent tooth and subsequent development of a dentigerous cyst with foci of calcifying odontogenic cyst. Complete enucleation of the cystic structure with retention of the associated tooth was performed, with a 6-month follow-up showing complete healing of the surgical site and no evidence of recurrence of the cystic lesion. To date, there have been only six reported cases of lesions with features of both calcifying odontogenic cyst and adenomatoid odontogenic tumor. The current case represents the first documented case of a dentigerous cyst with foci of both calcifying odontogenic cyst and adenomatoid odontogenic tumor. Given the variable nature and biological behavior of the odontogenic entities that compose hybrid odontogenic lesions, unusual clinical presentations and unexpected progression are possible. Further documentation of such hybrid lesions is necessary to fully elucidate how these entities behave clinically, radiographically and pathologically.