Dentinoma: a case report G.Margiotta*, T. Cutilli**, AR Vitale*, G. Coletti***, P. Leocata*. *Dept of Surgical Pathology, University of L’Aquila, L’Aquila, Italy** Dept of Maxillo-facial Surgery, Univeristy of L’Aquila, L’Aquila.*** Dept of Surgical Pathology, San Salvatore Hospital, L’Aquila. INTRODUCTION • “DENTINOMA” has been defined in 1971 by WHO as “a very rare neoplasm composed of odontogenic epithelium, immature connective tissue and dysplastic dentin”. • It generally occurs in young adults, without sex predilection. • The mandible represents the most common site of onset CASE REPORT We report on a case of a 41-year-old woman presented to our hospital for an asymptomatic, 1,5 cm in-diameter, radiolucent lesion of the mascellar. The lesion was excissed and the sample was processed routinarily in our laboratory (fixed in buffered formalyn 10%, decalcified with electrolytic decalcifyng solution, embedded in paraffin, sectioned at thickness of 4 μm, stained with Ematoxilin-Eosin with an automatic stainer) Immunoistochemestry was performed with Cytomation with antibodies provided by DAKO. DAKO DIAGNOSIS • Microscopically, the lesion consisted of dysplastic dentin without clear tubules, scanty epithelium and rare fibrous immature elements, stained positive for vimentin and cytocheratine. • The diagnosis of dentinoma was posed. HISTOLOGY: EE HISTOLOGY: EE IMMUNOISTOCHEMESTRY cytocheratine IMMUNOISTOCHEMESTRY vimentina DISCUSSION • First described by Straith in 1935, “dentinoma” is an entity that has not been fully accepted: some pathologists assume that this lesion must be regarded as ameloblastic fibroma or ameloblastic fibro-odontoma. • In our case, the presence of dysplastic dentin seems to preclude the diagnosis of ameloblastic fibroma, whereas the absence of enamel excludes the diagnosis of ameloblastic fibroodontoma. Thus, we hypothesize the diagnosis of dentinoma CONCLUSIONS • Up to now, only 20 cases diagnosed as dentinoma have been reported in literature. • The rarity of this entity and the difficulties in the differential diagnosis lead us to report on this case. BIBLIOGRAPHY • 1: Anthony H. Anker et al, Dentinoma of the mandible, Oral surg Oral med Oral Pathol, 1989; 67:731-3 • 2: Takeda Y. et al: So called immature dentinoma: a case presentation and histological comparison with ameloblastic fibrodentinoma. J Oral Pathol Med 1994; 23:92-96