So-called "immature dentinoma": a case presentation and histological comparison with ameloblastic fibrodentinoma.

The existence of the "dentinoma" as an independent entity has not been fully accepted, recently being regarded as an ameloblastic fibroma with formation of dentin and named an ameloblastic fibrodentinoma. However, there are histological differences between the several cases reported previously as "immature dentinoma" and the ameloblastic fibrodentinoma. This paper presents a case report of a dentin-forming intraosseous benign tumor without any histological features of ameloblastic fibroma. The patient was a 30-year-old woman with a rather well-circumscribed intraosseous lesion of the mandibular left premolar area. Histologically, the lesion consisted of dentin-like tissue with a tubular structure and globular calcifications, numerous epithelial strands and islands without enamel organ-like structure, and a cellular fibrous component without a primitive dental papilla-like appearance. The present case and a review of the literature suggest that epithelial elements in odontogenic fibroma-like lesions may occasionally have an inductive effect for dentin or dentin-like tissue formation.