Ameloblastoma : 2017 WHO Classification

The 2005 WHO classification of ameloblastomas consisted of solid/multicystic, extraosseous/peripheral, desmoplastic, and unicystic types.

The 2017 WHO classification includes:

• Ameloblastoma (75% to 85% of cases)
• Unicystic Ameloblastoma (15% to 20% of cases)
• Extraosseous (Peripheral) Ameloblastoma (1% to 4% of cases)

The term solid/cystic has been dropped because most conventional ameloblastomas show cystic changes. The desmoplastic type was moved under histologic subtypes instead of leaving it as a separate entity.

This gross photograph of a partial mandibulectomy shows a large mass (ameloblastoma) at the angle of the mandible.