Desmoplastic ameloblastoma: a systematic review of the cases reported in the literature.

The aim of this study was to integrate the available data published on desmoplastic ameloblastoma (DA) into a comprehensive analysis of its clinical/radiographic features. As it is not clear whether the hybrid ameloblastoma has a unique biological behaviour, the clinical/radiographic features of conventional DA were compared with those of the hybrid variant. An electronic search was undertaken in May 2019. Eligibility criteria included publications with sufficient clinical/radiographic/histological information to confirm the diagnosis. A total of 128 publications reporting 285 DAs were included (246 central non-hybrid, 33 central hybrid, 6 peripheral). There was a statistically significant difference between non-hybrid and hybrid cases concerning lesion location, radiographic limits, and size. In contrast to non-hybrid tumours, which showed a similar distribution in the mandible and maxilla, hybrid tumours showed a high predominance of mandible location. Non-hybrid lesions more often showed ill-defined radiographic margins, and were smaller tumours than hybrid DAs. Enucleation with an additional therapy (either curettage or peripheral osteotomy) or resection led to a lower recurrence risk in comparison to curettage or enucleation without additional therapy. The location of the lesion and type of treatment are related to tumour recurrence. There are important differences in location and radiographic limits between hybrid and non-hybrid DAs, which support their classification as distinct lesions.