Bilateral Radiolucencies of the Posterior Mandible:
A Clinicopathologic Review
In the case above, TN was considered given its proximity to the IANC. Due to asymptomatic nature, the separation of the lesion from the IANC, and lack of any surgical or traumatic history, TN was considered unlikely in the differential diagnoses. Furthermore, bilateral intraosseous traumatic neuromas have been reported, but are extraordinarily rare. 7
C. Idiopathic bone cavity( IBC)( also known as traumatic bone cyst or simple bone cyst) is a bone lesion with an unknown etiology, although there is a question of trauma playing a role in the development. However, cases of IBC have arisen without a history of trauma. 1 It usually presents surgically as an empty cavity, but occasionally can be a fluid-filled cavity. IBCs can present in any bone, with the long bones as the most common location. While they may be seen anywhere, when present in the mandible, the favored location of the lesion is the molar-premolar area or at the symphyseal area. 1 No gender predilection is reported in jaw lesions, and they are commonly seen in the second or third decade of life. IBCs are usually asymptomatic, and 20 percent of them can present with swelling. 1 Consequently, they are usually incidental findings on routine radiologic studies. Commonly, they present as single lesions, but occasionally multiple lesions can be present. 8 They are most likely to present as a well-circumscribed, unilocular radiolucencies radiographically, but some cases of ill-defined multilocular radiolucencies have been reported. Rarely, multiple IBCs have been reported in a patient. 9 The borders can range from well-corticated to diffuse. They can vary in size from a few millimeters to up to 10cm. The borders often scallop around the roots of teeth, with the teeth in the area remaining vital. A panoramic radiograph of an anterior IBC is included for comparison( Figure 3). It depicts a well-defined, unilocular radiolucency in the left mandibular premolar and canine area. It has the classic scalloping of the border around the roots of the teeth. IBC often mimic other bone lesions, such as periapical lesions or in our case, SDs. Histologically, the lesions contain fragments of thin, vascular, fibro-collagenous soft tissue with a lack of epithelial cystic lining. Red blood cells and osteoid-like material may be seen along with osteoclastic, multinucleated giant cells and calcifications. The lesion lacks an epithelial cystic lining, and therefore is not a true cyst. Hence, traumatic bone cyst and simple bone cyst are misnomers, and IBC is the preferred terminology.
Treatment involves surgical exploration and curettage. Exposure with or without curettage is enough to induce bone regeneration. Although minimal tissue is usually obtained from curettage, it is advisable to submit the tissue for histopathologic review to confirm the diagnosis.
Figure 2: A computed tomography scan with bilateral, well-circumscribed, unilocular radiolucencies in the posterior mandible which are in communication with the inferior alveolar nerve. Histologically, these lesions are compatible with bilateral intraosseous traumatic neuromas.
Figure 3: A panoramic radiograph with a well-circumscribed, unilocular radiolucency present in the anterior left mandible. Its borders scallop around the roots of the canine and premolar.
JANUARY / FEBRUARY 2017 | PENNSYLVANIA DENTAL JOURNAL 31