Osteoid osteoma in the mandible: Case report

RAFAEL SARAIVA TORRES1 | SAULO LOBO CHATEUBRIAND DO NASCIMENTO1 | PAULO MATHEUS HONDA TAVARES1 | VALBER BARBOSA MARTINS1 | JOEL MOTTA JUNIOR1 | GUSTAVO CAVALCANTI DE ALBUQUERQUE1 | MARCELO VINICIUS OLIVEIRA1

Osteoid osteoma is a benign tumor characterized by limited growth. It is more common in long bones and extremely rare in gnatic bones. It is typically presented as an injury that causes pain mainly at night, which can be alleviated with the use of non-steroidal anti-inflammatory drugs. Radiographically is a radiopaque lesion delimited by a radiolucent region. It usually does not exceed 20 mm in diameter. The treatment of choice is usually surgical removal, and recurrence is very rare. The purpose of this study is to report a case of a rare osteoid osteoma in the posterior mandible region, near the mandibular canal. Radiographically, is presented as a sclerotic lesion, well delimited, surrounded by a radiolucent halo. Clinically, it caused recurrent discomfort to the patient. Surgical removal was performed in an outpatient setting under local anesthesia. After the lesion was excised, the patient presented resolution of the symptoms.

Keywords: Osteoma, osteoid. Bone neoplasms. Tomography.

1 Universidade do Estado do Amazonas, Programa de Residência em Cirurgia e Traumatologia

Buco-maxilo-facial (Manaus/AM, Brazil).

» The authors report no commercial, proprietary or financial interest in the products or companies described in this article.

» Patients displayed in this article previously approved the use of their facial and intraoral photographs. How to cite: Torres RS, Nascimento SLC, Tavares PMH, Martins VB, Motta Junior J, Albuquerque GC, Oliveira MV. Osteoid osteoma in the mandible: Case report. J Braz Coll Oral Maxillofac Surg. 2021 Jan-Apr;7(1):50-4. DOI: https://doi.org/10.14436/2358-2782.7.1.050-054.oar

Submitted: October 22, 2018 - Revised and accepted: February 07, 2019

Contact address: Rafael Saraiva Torres E-mail: saraivatorres@gmail.com

The osteoid osteoma is characterized as a tumor of benign origin, with the first reports by Heine; histology by Bergstrand; and, in 1953, Jaffe described and classified it as a clinical and pathological entity. This allowed to differentiate it from other tumors.1 It is a benign primary tumor whose niche is composed of hypervascular immature osteoid tissue surrounded by reactive sclerotic bone. It has low growth potential and usually has diameter smaller than 15mm.1

The osteoid osteoma can develop in multiple locations, yet it is most often seen in the long bones of the lower limbs, i.e., the femur, tibia and fibula, with less than 1% occurring in the jaws. The male-to-female ratio is about 4:1 and it predominates in children and young adults from the first to the third decade of life. The most common symptom is localized bone pain, which can be relieved with the use of non-steroidal anti-inflammatory drugs (NSAIDs).1,2

In the oral and maxillofacial complex, this type of lesion is commonly described, mainly in the mandible, in the molar region; however, few cases have been reported.3 Radiographically, it is characterized by the presence of a radiolucent area, with small diameters, rarely exceeding 20 mm, almost always surrounded by reactive sclerotic bone.2 Its occurrence in the mandible usually mimics most common odontogenic lesions, such as cementoblastoma and osteoblastoma. Imaging exams can often favor a better characterization of the niche; these include magnetic resonance imaging and computed tomography. Bone scintigraphy can also show intense niche activity and low activity in the region of surrounding reactive zone; however, anatomopathological examination is responsible for the final diagnosis.4,5

Macroscopically, the niche is wine-colored and almost always well defined. In most cases, it does not exceed 2 cm in diameter. Microscopically, it is composed of mature bone trabeculae and an osteoid matrix with abundant vascularization. In some cases, it presents central calcification zones. It is believed that its etiology may be related to continuous muscle traction and osteogenic reactions, hamartomatous events, inflammatory processes or even healing of trauma in the final stage.6

The main treatment option for these tumors has been classic surgery for a long time. Thus, the options are curettage, en bloc resection and wide resection (with graft). Complete removal of the lesion assures the absence of relapse. If the osteoid osteoma is located deeply, the surgical procedure will be difficult. The success rate of classic surgery ranges from 88% to 100%. However, the main point of concern is the occurrence of complications such as necrosis and fractures.7 According to Cantwell et al.9, complications occur in 20-45% of procedures. Besides these complications, the surgical time is longer, and tissue damage, healing and morbidity are greater compared to minimally invasive therapies.

Although osteoid osteoma is considered a latent lesion, it also requires a strategic approach, so that surgery has minimal invasion, but allows complete lesion removal.9

Female patient, Caucasoid, aged 23 years, was referred to the Oral and Maxillofacial Surgery and Traumatology service at the State University of Amazonas, complaining of discomfort in the region of tooth 37, with repercussion on the left ear, besides episodes of recurrent paresthesia, with one year of evolution.

The patient did not report history of trauma or infection in the dental region, only reporting that she had undergone extraction of tooth 38 exactly three years ago, due to orthodontic indication.

Extraoral examination did not reveal facial asymmetry or bone alteration during palpation, as well as on the intraoral examination, which showed normality at the region of pain complaint.

Imaging examination revealed a radiopaque image, with well-defined margins, in the region of tooth 38. In the parasagittal section, the lesion was 7.80 mm high and 6.60 mm wide. The suggestive diagnosis at first was complex odontoma (Fig 1).

Surgical removal of the lesion under local anesthesia was planned in the outpatient clinic. Access to the mandible was achieved by intraoral approach, with a flap extending up to the mesial aspect of tooth 37, with full mucoperiosteal detachment, followed by osteotomy for lesion exposure and removal (Fig 2).

After complete removal, the specimen obtained was submitted to histopathological examination, which showed mineralized material with prominent reverse lines and sheets of irregular trabeculae, evidencing a lesion of osteoid osteoma type (Fig 2).

At seven days postoperatively the patient had no complications, only discomfort in that region. At 12 months after surgical removal the patient did not have any complaint, thus presenting an excellent prognosis (Fig 3).

Figure 1: Computed tomography presenting, on panoramic and parasagittal sections, a radiopaque image with well-defined margins, in the region of tooth 38.

Figure 2: Transoperative aspect: A) Flap extending to the mesial surface of tooth 37 (similar to the access for third molar removal). B) Osteotomy for lesion exposure and removal. C) Macroscopic aspect. D) Histopathological aspect, showing mineralized material with prominent reverse lines and irregular trabeculae.

Figure 3: Computed tomography at 12 months postoperatively, showing new bone formation and lesion resolution.

Osteoid osteoma is a benign lesion that consists of a small, rounded nest. It accounts for 3% of all primary bone tumors and about 10% of benign bone tumors. About 80% of osteoid osteomas occur in long bones, while less than 1% occur in the jaws. Mild pain and discomfort are the main symptoms, as in the present case.10

Analysis of reports in the literature reveals that most osteoid osteomas of the jaws occur in the second and third decades of life, and the majority of cases were reported in the mandible, not the maxilla.1,3,5,6 This is because the posterior mandibular body, especially the molar region, is more prone to development of this lesion, which coincides with the present case report.

The actual prevalence of osteoid osteoma is unknown. It is more frequently observed in men than women, at a ratio of approximately 4:1,1,2,10 contrasting with the present study, which reports a case in a female patient.

The exact etiology and pathogenesis of osteoid osteoma is unknown. Neoplastic and reactive causes have been suggested as possible etiological factors. It is believed that its etiology may be related to continuous muscle traction and osteogenic reactions, hamartomatous events, inflammatory processes or even final healing stage of trauma.8 However, in the present case, we only have information about extraction of tooth 38 approximately three years before, which may be a possible cause.

Histologically, osteoid osteomas consist of compact bone, which are interconnected and are sometimes separated by small medullary spaces as reported in this case. Radiographically, osteomas show a well-circumscribed, densely sclerotic and radiopaque mass. They are usually identified in routine radiographic examination and treated by local excision,9 data that coincide with the present case.

Recurrence after surgical excision is extremely rare.1,2,5,8,9 The present case had a good prognostic evolution, without relapse of neoplasia. Removal was performed effectively, thus showing no harmful signs and symptoms postoperatively.

Osteoid osteoma of the mandible is a benign neoplasm that is increasingly frequent, even though it is of unknown origin. Imaging methods are used in the evaluation of osteoid osteoma, such as computed tomography, which play a fundamental role in identifying the lesion. Surgery remains the standard treatment in cases where the histology of the lesion is doubtful.

The present case is similar to cases reported in most national and international literature, demonstrating that the evolution, diagnosis, treatment and prognosis do not differ in different regions.

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