a 27-year - old woman was referred for evaluation of a mass in the right side of face between eye and nose . the patient stated that the mass had first appeared 2 years ago and had been gradually increasing in size ever since . the host had non - specific headache , and no visual disturbances , dysphagia or dyspnea . , there was a soft tissue mass occupying right ethmoid and sphenoid sinuses destructing the bony lamina papyracea and minimally extended into the right globe . there is also destruction of the posterior wall of the mentioned sinuses and is extended into the right frontal lobe extra - axially ( figure 1 ) . brain coronal ct scanning there is a soft tissue mass occupying right ethmoid and sphenoid sinuses destructing the bony lamina papyracea and minimally extended into the right globe . there is also destruction of the posterior wall of the mentioned sinuses and is extended into the right frontal lobe extra - axially . on brain mri study , a mass occupying right ethmoid sinus and partially sphenoid sinus was seen which is isosignal to hyposignal to gray matter on t1-weighted sagittal image ( figure 2 ) , and isosignal to gray matter on proton density axial image ( figure 3 ) . the mass was extended to right globe and right frontal lobe extra - axially with no surrounding edema . brain mri study a mass occupying right ethmoid sinus and partially sphenoid sinus is seen which is isosignal to hyposignal to gray matter on t1-weighted sagittal image . brain mri study a mass occupying right ethmoid sinus and partially sphenoid sinus is seen which is isosignal to gray matter on proton density axial image . there was pressure on the right globe and frontal lobe , but no invasion to optic nerve or brain tissue was seen . pathology sample with h&e staining on low and high power fields showed psammo - ma - like masses with ossification in cellular stroma . central cemeto - ossifying fibromas are a distinct form of benign fibro - osseous lesions of the mandible and maxilla . they are believed to be originated from the periodontal ligament and are made up of various amounts of cementum , bone , and fibrous tissue . the hybrid name central cemento - ossifying fibroma is used because there is a spectrum of fibro - osseous lesions that arise from the periodontal ligament , ranging from those with only deposition of cementum to those with only deposition of bone.10 central cemento - ossifying fibroma is more common in women than in men . they arise in the mandible in 62% to 89% of patients , 77% occurring in the premolar region . most are diagnosed between 20 and 40 years of age.10 when the tumor occurs in children , it is called the juvenile aggressive cemento - ossifying fibroma , which presents at childhood age and is clinically more aggressive and pathologically more vascular.10 central cemento - ossifying fibromas are asymptomatic if they are not expanded . therefore , they are generally not diagnosed until the tumor has had time to produce calcifications . although the mandible is a common site for central cemento - ossifying fibromas , the maxillary sinus is an unusual site for central cemen - to - ossifying fibromas . central cemento - ossifying fibromas are typically well - circumscribed , solitary radiolucencies with scattered radiopaque foci . they maintain a round shape , expand the surrounding cortical bone with no cortical violation , and may cause tooth divergence . the expanded tumors may involve the nasal septum , infraorbital foramen , and orbital floor . at the time of diagnosis , maxillary central cemento - ossifying fibromas are large ; indicating the ability of the tumor to expand freely within the maxillary sinus . pathologic examination of the central cemento - ossifying fibroma represents a sum of irregularly - shaped calcifications within a hypercellular fibrous connective tissue stroma . the appearance of calcifications is extremely variable and shows different stages of bone and cementum deposition . most of the calcified fragments are immature cementum , with basophilic coloration on hemotoxillin and eosin - stained sections , which are called central cementifying fibroma . in other cases , the calcified fragments are osteoid , with typical eosinophilic coloration on hemotoxillin and eosin - stained sections , which are called central ossifying fibromas . however , central ossifying fibromas can also be basophilic , causing difficulty in differentiating from central cementifying fibromas . most pathologists believe that these two tumors namely central ossifying fibromas and central cementifying fibromas arise from the same progenitor cell ; producing different amounts of bone and cementum within any one lesion . the hybrid central cemento - ossifying fibroma has evolved to indicate the likely presence of both types of tissue within the same lesion . it is due to two reasons : difficulty in distinguishing reliably immature cementum from immature bone and the presence of both of these substances in many lesions . therefore , the most accurate histological term is central cemento - ossifying fibroma , but it is interchangeable with either central ossifying fibroma or central cementifying fibroma . apparently , there is no clinical or radiologic difference between the central ossifying fibroma and central cementifying fibroma , so the hybrid central cemento - ossifying fibroma is useful enough for radiology , too.10 the differential diagnoses includes other lesions that contain radiopacities within a rounded radiolucent mass : osteosarcoma or chondrosarcoma , odon - togenic cysts , fibrous dysplasia , calcifying odontogenic cysts ( gorlin cysts ) , calcifying epithelial odontogenic tumors ( pindborg tumors ) , and squamous cell carcinomas . the factor that can differentiate central cemento - ossifying fibroma from aggressive sarcomas and carcinomas is its well - defined border . fibrous dysplasia contains a characteristic of  ground glass  appearance that can not be found in the central cemento - ossifying fibroma . the radiologic differentiation of central cemento - ossifying fibroma from gorlin cysts and pindborg tumors is difficult ; the final diagnosis is based on histological appearance . there is a strong association between pindborg tumors and impacted teeth.10 surgical excision is the recommended treatment for the central cemento - ossifying fibroma . the entire tumor should be excised including involved regions of the maxillary sinus walls and orbital floor . central cemento - ossifying fibromas usually  shell out  easily at surgery ; however , maxillary types are more difficult to remove totally than mandibular types . this may be attributable to the difference in bone character between the mandible and maxilla and to the available apace for expansion in the maxillary sinus . the recurrence rate of mandibular central cemento - ossifying fibromas is as many as 28% of patients . the recurrence rate of maxillary central cemento - ossifying fibromas is unknown , but it is likely to be higher because of the greater difficulty of their surgical removal and larger size at the time of presentation.1011
cemento - ossifying fibroma is a lesion containing both fibrous and osseous components . 
 such lesions include fibrous dysplasia , ossifying fibroma , cemento - ossifying fibroma and cementifying fibroma . 
 periodontal membrane is the origin of fibro - osseous lesions other than fibrous dysplasia.here a clinical case of a young woman referred for evaluation of a mass in the right side of face between eye and nose is presented . the first time she noticed the mass was 2 years ago and was growing larger inwards . 
 she was treated with surgical resection.in this case of a cemento - ossifying fibroma , histological interpretation was critical , and was the basis of correct treatment .