calcifying epithelial odontogenic tumor ( ceot ) is an odontogenic tumor arising from the odontogenic epithelium . it was first described in 1956 by the late dr . histogenesis is uncertain and is believed to arise from remnants of dental lamina and stratum intermedium . here a 42-year - old male patient reported to our institution with a chief complaint of a swelling in the right side of the mandible in the region of 43 , 44 , and 45 . extraorally , there was a diffuse swelling on the right side of the face with associated facial asymmetry . intraorally , there was an exophytic soft tissue overgrowth in the region of 43 and 44 . on palpation , the intraoral swelling was smooth , firm , and nontender with bicortical expansion of both buccal and lingual cortical plates . there was a displacement of 42 and 44 with grade iii mobility [ figure 1 ] . exophytic growth in relation to 42 , 43 , 44 , and 45 radiographic examination revealed missing 43 and 44 with a multilocular radiolucency , sclerotic borders , and displacement of 42 and 45 . mandibular occlusal view radiographs revealed bicortical expansion of both buccal and lingual cortical plates . computed tomography scan with three - dimensional reconstruction showed an expansile soft tissue mass with areas of calcification [ figure 3 ] . multilocular radiolucency with many radiopaque spots of driven snow appearance computed tomography reconstructed image of the lesion incisional biopsy was done , and a small bit of lesional tissue was given for histopathological examination . histopathology of the excised specimen showed islands and strands of polyhedral epithelial cells with prominent intercellular bridges . leisegang ring type of calcifications were also seen [ figures 4 and 5 ] . from the histopathology , a diagnosis of ceot / pindborg tumor was made . epithelial cells with prominent intercellular bridge and amyloid - like material leisegang ring calcifications and amyloid - like material in connective tissue stroma the patient was advised to come for regular follow - up to monitor the healing and prognosis . the follow - up of 1 year revealed good healing of the site and no recurrence . it was first described by the oral pathologist pindborg , so ceot is also called pindborg tumor . this is based on the morphological resemblance of tumor cells to that stratum intermedium and a high activity of alkaline phosphatase and adenosine triphosphate in both these cells . the tumor occurs most commonly in the middle age , and the mean age was 40 years . the present case was reported in a 42-year - old patient with a painless swelling in the mandibular premolar region . the radiographic features of the tumor may be unilocular or multilocular radiolucency . in our case , it was multilocular . approximately , 50% of the cases are associated with an unerupted tooth or odontome , but was not so with our case . histopathologic feature usually shows islands and strands of polyhedral epithelial cells with nuclear pleomorphism , prominent nucleoli , and intercellular bridges . one of the characteristic microscopic features of this tumor is the presence of amorphous , eosinophilic hyalinized , and acellular areas resembling amyloid within or adjacent to epithelial islands . many histologic , histochemical , immunohistochemical , and electron microscopic investigations were done to identify the nature of amyloid - like material in pindborg tumor . studied the histologic , histochemical , fluorescent , and ultrastructural study of ceot and found that eosinophilic substance was not amyloid . it is now identified that this material has a unique protein that has similarity with enamel proteins and is produced by this tumor cells . another characteristic feature of this tumor is the presence of concentric ring of basophilic calcifications called leisegang rings within the amyloid - like masses . these leisegang ring calcifications were thought to be a form of dystrophic calcification and cemental masses . they usually fuse to form large masses of calcification . on rare occasions , clear cells , langerhan cells , and myoepithelial cell the follow - up of 1 year showed good healing of the site and no recurrence . we have reported a rare case of ceot or pindborg tumor which was diagnosed and confirmed as ceot by incisional and excisional biopsy . it is an extremely rare odontogenic tumor and included in differential diagnosis of all the odontogenic tumors .
calcifying epithelial odontogenic tumor ( ceot ) , also known as pindborg tumor , is a rare odontogenic epithelial neoplasm . 
 so far , nearly 200 cases have been reported in the literature . 
 we are reporting a case of ceot in a 42-year - old male patient with painless bony swelling in the mandible . 
 the clinical , radiographic , and histopathologic features are discussed with relevant references .