The desmo- and osteoplastic ameloblastoma. Histologic variant or clinicopathologic entity? Case reports.

Two cases of desmoplastic ameloblastoma (DA) are presented, bringing the total number of reported cases to 29. One case of the so-called "hybrid lesion" is added to the presentation. Immunohistochemical studies indicate that the desmoplasia is caused by active de novo synthesis of extracellular matrix proteins. Moreover, the DA may also show osteoplasia, and this probably explains the characteristic radiographic appearance of many DAs, i.e. the occurrence of both radiolucent and radiopaque changes, suggestive of a fibro-osseous lesion. Many more cases of DA are needed to clarify the true nature of this most interesting tumor.