oprm-web-case-op-st-47

Patient: Young adult, either sex.

Chief Complaint:
The patient is concerned about a bony swelling of the mandible. The lesion is persistent, progressively increasing in size, nontender and of several months duration. The patient reports bruising the swelling when chewing something hard.

Medical History:
No abnormalities are identified.

Dental History:
No dental abnormalities relevant to the diagnosis of this case are identified.

Clinical Findings:
The enlargement involves the right posterior alveolus and body of the mandible with evidence of buccal and lingual expansion. The enlargement is firm and nontender. Crepitus is evident on palpation of the lingual cortical plate. The mandibular right first molar demonstrates vertical mobility. Radiographic examination reveals a circumscribed, delineated, radiolucent lesion with a corticated border in the right body and ramus of the mandible. The second molar is displaced posteriorly and inferiorly. There is directional root resorption of the first molar. The inferior mandibular cortical plate is thinned. Neuropathy, thrill and bruit are not present.

There are no clinical images available for this case.

There are no lab reports available for this case.

There are no charts available for this case.

Summary:
The patient is concerned about a persistent, progressive, nontender, bony swelling of the right posterior alveolus and body of the mandible that is of several months duration.  The enlargement demonstrates buccal and lingual expansion.  Crepitus is evident on palpation of the lingual cortical plate.  The mandibular right first molar demonstrates vertical mobility.  The image of the radiograph in this case is difficult to interpret, however radiographic examination of the original radiograph reveals a well-circumscribed radiolucent lesion with a corticated border in the right body and ramus of the mandible.  The second molar is displaced posteriorly and inferiorly.  There is directional root resorption of the first molar.  The inferior cortical plate of the mandible is thinned.  Neuropathy, thrill and bruit are not present. 

Lesions to Exclude from the Differential Diagnosis:
The radiographic features are described as a radiolucent lesion with well-defined, corticated borders.  Lesions that are consistently radiopaque are excluded from the clinical differential diagnosis.  Radiopaque benign odontogenic tumors that are excluded include odontomas and cementoblastoma.  Radiopaque benign nonodontogenic tumors that can be excluded include osteoma and monostotic fibrous dysplasia, which is also excluded because it has poorly defined borders.   

Within the category of cysts, the following lesions may be excluded.  Radicular cyst (and granuloma and abscess) may be excluded because the lesion in this case is not associated with the apical region of a non-vital tooth.  Primordial cyst can be excluded because there are no congenitally missing teeth.  Lateral periodontal cyst and nasopalatine duct (incisive canal) cyst can be excluded because of location.  Eruption cyst can be excluded because it is a soft tissue lesion associated with an erupting tooth.

Within the category of variable radiolucent-radiopaque benign odontogenic tumors, the following lesions may be excluded.  Periapical cemento-osseous dysplasia and focal cemento-osseous dysplasia can be excluded because these lesions do not grow to such a large size, do not cause bony expansion, and do not displace teeth.  Also, the larger or more mature lesions tend to have a mineralized radiopaque product.   

From the category of radiolucent benign nonodontogenic tumors, central arteriovenous malformation is excluded because it is associated with a thrill and a bruit. 

From the category of “other” radiolucent lesions, lingual salivary gland defect (Stafne defect) can be excluded because they do not attain such a large size, they are located inferior to the inferior alveolar canal, they do not cause expansion of the mandible, and they do not result in crepitus with palpation.  Idiopathic bone cavity can be excluded because it does not cause expansion of the mandible or crepitus with palpation.   

Lesions to Include in the Differential Diagnosis:
The differential diagnosis includes dentigerous cyst, odontogenic keratocyst, ameloblastoma, ameloblastic fibroma, central odontogenic fibroma, central giant cell granuloma, and non-ossifying fibroma.  Odontogenic myxoma is unlikely because the lesion in this case has corticated borders.

Other lesions that are possible but unlikely because of the absence of radiopaque foci within such a large radiolucent lesion include adenomatoid odontogenic tumor, calcifying epithelial odontogenic tumor, calcifying odontogenic cyst, ameloblastic fibro-odontoma,   ossifying/cementifying fibroma,  and chondroma.

Initial Management:
An incisional biopsy representative of the entire lesion with microscopic diagnosis is recommended because of the different modes of surgical treatment of lesions included in the differential diagnosis.

Final Diagnosis:
Odontogenic keratocyst

Treatment and Prognosis:
Treatment is controversial, but includes complete surgical removal with peripheral ostectomy.  Long-term radiographic follow-up is necessary because of the high recurrence rate of odontogenic keratocysts.  Also, if odontogenic keratocysts develop in a different location in the jaws, the patient should be evaluated for nevoid basal cell carcinoma syndrome (basal cell nevus syndrome, Gorlin-Goltz syndrome).