Indian Journal of Pathology and Microbiology

: 2016  |  Volume : 59  |  Issue : 2  |  Page : 256--257

Mixed odontogenic tumor

Treville Pereira, Subraj Shetty 
 Department of Oral and Maxillofacial Pathology and Microbiology, D. Y. Patil University School of Dentistry, Navi Mumbai, Maharashtra, India

Correspondence Address:
Treville Pereira
Department of Oral and Maxillofacial Pathology and Microbiology, D. Y. Patil University School of Dentistry, Sector 7, Nerul, Navi Mumbai - 400 706, Maharashtra

How to cite this article:
Pereira T, Shetty S. Mixed odontogenic tumor.Indian J Pathol Microbiol 2016;59:256-257

How to cite this URL:
Pereira T, Shetty S. Mixed odontogenic tumor. Indian J Pathol Microbiol [serial online] 2016 [cited 2020 Aug 6 ];59:256-257
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Odontogenic tumors are a group of lesions, which are not only true neoplasms but also hamartomas.[1] The solid/multicystic ameloblastoma (A-S/M) and calcifying cystic odontogenic tumor (CCOT) are well-recognized odontogenic tumors in the oro-maxillofacial region, whereas mixed odontogenic tumors have been rarely reported.[2] A 30-year-old female reported with a painless swelling on the left side of the face for 6 months, which was progressive in nature. Heaviness and stuffiness of the left cheek with numbness of the nose was noted. On examination, a diffuse extraoral swelling extending from the ala of the nose to the tragus of the ear of 6 cm × 2 cm size was observed. The coronal computed tomography scan showed a large, homogeneous soft tissue mass occupying the left maxillary sinus and encroaching into the left nasal cavity and ethmoid sinus. Past dental history revealed a similar swelling 6 years back, for which a pathological diagnosis of adenomatoid odontogenic tumor (AOT) was given that recurred 3 years later and was again diagnosed as a follicular ameloblastoma. Segmental resection of the left maxilla was done. Hematoxylin and eosin stained section showed an odontogenic cystic lining of low cuboidal to flattened squamous cells with basophilic nuclei. Some islands of odontogenic epithelium had basal cells, which were columnar and hyperchromatic with palisading and reversal of polarity. Central cells resembled stellate reticulum. Nests of ghost cells were observed suggestive of CCOT. Deposits of scattered dentinoid were also noted. Based on this diverse histopathological feature, a diagnosis of mixed odontogenic tumor comprising of A-S/M and CCOT was made [Figure 1]. The World Health Organization has classified CCOT as a “benign neoplasm related to odontogenic apparatus.”[2] The characteristic feature of CCOT is an ameloblastic epithelium with variable amount of ghost cells. These ghost cells represent the stages of aberrant keratin formation or a product of an abortive enamel matrix in odontogenic epithelium.[3] The CCOT usually occurs in association with odontoma, A-S/M, ameloblastic fibroma, AOT, ameloblastic fibro-odontoma, and odontogenic myxofibroma.[4] In the present case, a unique histological feature was the evidence of ghost cells, which stained positive for Van-Gieson stain. Modified Gallego's staining was done to confirm the presence of dentinoid [Figure 2]. The proliferation of the odontogenic epithelium from the cyst lining and the condensation of cells within the stroma resembled primary ectomesenchymal induction of the dental lamina.[4] The formation of dysplastic dentin in these tumors is considered as a result of a metaplastic process rather than an epithelial-mesenchymal interaction. It is possible that the neoplastic epithelial cells could cause the ameloblastic differentiation, which may have produced the dentinoid.[5] The prognosis of this composite odontogenic tumor is determined by its treatment. Multiple histological components make the treatment of these lesions rather difficult. In the present case, surgical resection of the left maxilla was performed, and a 1-year follow-up showed no recurrence.{Figure 1}{Figure 2}


1Etit D, Uyaroglu MA, Erdogan N. Mixed odontogenic tumor: Ameloblastoma and calcifying epithelial odontogenic tumor. Indian J Pathol Microbiol 2010;53:122-4.
2Lin CC, Chen CH, Lin LM, Chen YK, Wright JM, Kessler HP, et al. Calcifying odontogenic cyst with ameloblastic fibroma: Report of three cases. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2004;98:451-60.
3Kusama K, Katayama Y, Oba K, Ishige T, Kebusa Y, Okazawa J, et al. Expression of hard alpha-keratins in pilomatrixoma, craniopharyngioma, and calcifying odontogenic cyst. Am J Clin Pathol 2005;123:376-81.
4Zhang W, Chen Y, Geng N, Bao D, Yang M. A case report of a hybrid odontogenic tumor: Ameloblastoma and adenomatoid odontogenic tumor in calcifying cystic odontogenic tumor. Oral Oncol 2006;42:287-90.
5Papagerakis P, Peuchmaur M, Hotton D, Ferkdadji L, Delmas P, Sasaki S, et al. Aberrant gene expression in epithelial cells of mixed odontogenic tumors. J Dent Res 1999;78:20-30.