A huge osteoma of the mandible detected with head and neck computed tomography

Abstract

a b s t r a c tWe encountered a patient with a huge osteoma extending over half of the mandible, which was incidentally discovered on a head-and-neck computed tomography (CT) by an otolaryngological examination for vertigo.A tumorous lesion of the right mandible was noted, and the patient was referred to our department. The tumor extended from the median mandible over the right anterior margin of the ramus of the mandible.To improve the abnormal intraoral morphology, tumor resection and orthopedic surgery were performed. The histopathological diagnosis was a cancellous osteoma.Dentures were attached after surgery, and the postoperative course has been favorable with no tumor re-enlargement.

A case of mandibular peripheral osteoma on the inferior border of the mandible

“…The differential diagnosis of osteoma must always include exostosis 2‐4 . Exostosis consists of the outward‐directed nontumorous growth of bony tissue, and its occurrence on the mandible is known as “torus mandibularis” and on the palate as “torus palatinus” 2,3 .…”

“…Some authors have argued that one difference between them is that osteomas contain a medullary cavity, which is not present in exostoses 5,6 . Others have suggested that they are so similar that they are often difficult to distinguish, 4 and histologically their differentiation is problematic. Some studies have reported that exostosis ceases to increase in size at the conclusion of skeletal bone growth, whereas osteomas continue to grow 2‐4,7,8 .…”

“…Others have suggested that they are so similar that they are often difficult to distinguish, 4 and histologically their differentiation is problematic. Some studies have reported that exostosis ceases to increase in size at the conclusion of skeletal bone growth, whereas osteomas continue to grow 2‐4,7,8 . It was reported that bone scintigraphy showed a circular area of radioisotope accumulation with indistinct boundaries, consistent with a tumor lesion, 4,9 but as diagnostic criteria these are also ambiguous.…”

“…Some studies have reported that exostosis ceases to increase in size at the conclusion of skeletal bone growth, whereas osteomas continue to grow 2‐4,7,8 . It was reported that bone scintigraphy showed a circular area of radioisotope accumulation with indistinct boundaries, consistent with a tumor lesion, 4,9 but as diagnostic criteria these are also ambiguous. In the WHO classification, the 2005 version described exostosis as synonymous with osteoma, stating that the etiology of osteoma is not clear, and it consists of a spherical, pedunculated lesion composed of cortical lamellar bone on the outside overlying trabecular bone, with intervening marrow spaces on histological examination, whereas exostosis appears to be related to trauma and does not usually show marrow spaces 6 .…”

“…If other bone‐related diseases have been excluded by radiography and CT examinations, bone scintigraphy, and other imaging modalities, bone growth regarded as due to occlusal force, trauma, or other physical stimulus on the basis of its location, course, and clinical pathophysiology is clinically classified as “exostosis,” and lesions that show autonomous growth in the absence of such physical stimuli are classified as true “osteomas.” We attempted to re‐evaluate the previously reported 11 cases of “osteomas” by our proposed criteria (Table 1). Five cases were considered as “true osteoma” 2,4,10,11,12 and others are considered as reactive bone formation called “exostosis” 3,5,7,8,9,12 . Further studies with many cases are needed in order to reach a consensus for the differentiation criteria between neoplastic peripheral osteoma and exostosis of the mandible．…”