Secretory cells in adenomatoid odontogenic tumour: tissue induction or metaplastic mineralisation?

To undertake a detailed histological investigation of a large series of adenomatoid odontogenic tumours (AOT) to document the frequency and histomorphology of secretory cells which might indicate an inductive capacity.

Haematoxylin and eosin stained sections of 51 cases of AOT were reviewed. Selected cases were stained with periodic acid-schiff (PAS) and Congo red.

In five cases, secretory structures with a circular arrangement of tall columnar cells secreting enameloid-like matrix material were identified. Such structures have only very rarely been identified in AOT and their frequency, distribution and morphology have not been adequately documented.

We have documented the presence of tall secretory columnar cells, arranged in a circular configuration actively secreting enameloid-like material and believe that such an ordered arrangement of secretory cells is more likely a result of tissue induction rather than metaplasia. The origin of these secretory structures from the pseudo-ductular component is unlikely but cannot be ruled out.