The 2005 WHO histological classification of odontogenic tumours lays out a classification system for neoplasms and other tumours related to the odontogenic apparatus. At the time of writing (2016), it is still the most widely used classification system. 

Classification

Malignant tumours

• odontogenic carcinomas
  • malignant ameloblastoma
  • ameloblastic carcinoma: primary type
  • ameloblastic carcinoma: secondary type (dedifferentiated), intraosseous
  • ameloblastic carcinoma: secondary type (dedifferentiated), peripheral
  • primary intraosseous squamous cell carcinoma: solid type
  • primary intraosseous squamous cell carcinoma derived from keratocystic odontogenic tumour
  • primary intraosseous squamous cell carcinoma derived from an odontogenic cyst 
  • clear cell odontogenic carcinoma
  • ghost cell odontogenic carcinoma