Central fibroma of the jaw, odontogenic or desmoplastic.

Discerning desmoplastic fibroma from odontogenic fibroma may present considerable diagnostic difficulty. In the present article five cases of jaw fibroma serve to emphasize the various problems. Two cases represented desmoplastic fibroma. Both were treated by curettage, which was successful in one case but failed to provide a cure in the other. Factors responsible for this differing clinical course are discussed. A third case of desmoplastic fibroma proved to have been misdiagnosed, being a low-grade fibrosarcoma that subsequently showed dedifferentiation, and two cases were diagnosed as central odontogenic fibroma. After a discussion of the various histologic aspects of the reported cases, it is concluded tha desmoplastic fibroma is a well-delineated entity. Odontogenic fibroma, on the contrary, can exhibit a varying histomorphology, perhaps because of the existence of different entities that at present are taken together. To prevent the uncertainties concerning the odontogenic fibroma from making the definition of desmoplastic fibroma also indistinct, it is proposed that a central jaw fibroma that does not show the typical morphology of a desmoplastic fibroma should be considered an odontogenic fibroma.