Analysis of demographic differences according to histomorphological subtypes of 1312 cases of ameloblastoma.

Introduction: Ameloblastoma is a benign but locally aggressive odontogenic tumour broadly divided into conventional, unicystic, peripheral, adenoid and metastasising types. The first three entities compose the majority and especially the conventional type which has different histopathological subtypes such as follicular, plexiform, acanthomatous, granular cell, basal cell and desmoplastic have been described. We report the largest series of ameloblastoma in a single study to analyse the demographic characteristics according to histopathological subtypes of ameloblastoma.

Materials and methods: 1,312 cases of ameloblastoma reported from two centres in Sri Lanka and Malaysia were analysed according to age, site and histopathological subtype.

Results: Of the total of 1,312 cases, the mean age for conventional ameloblastoma (excluding desmolastic subtype) was 36.82±16.57. It was 46.3±15.21 for categorisewhile peripheral and unicystic ameloblastoma occurred at 40.77±16.35 and 31.00±17.37, respectively. Ninety percent of the cases were in the mandible (p=0.00001) with significant predilection for the right side. Unicystic and plexiform subtypes were mostly seen in the 11-20 age group while the desmoplastic subtype was seen in the 51-60 age group. The commonesthistological subtype was follicular subtype and acanthomatous changes were observed predominately in combination with follicular subtype. Majority of the acanthomatous subtype was observed inposterior mandible (p=0.00001). The frequency of luminal (243) and mural (246) subtypes werealmost similar.

Conclusion: This study provides a comprehensive demographic detail of differenthistological subtypes of ameloblastoma using the largest sample in the literature. The present findingswill be helpful in classification and understanding of different subtypes of the tumours.