Volume 3, Issue 4 , Pages 182-187, December 2008
Cementoblastoma previously misdiagnosed as fibrous dysplasia: Report of an uncommon case and discussion of the differential diagnosis
Article Outline
Summary
Cementoblastoma is a rare odontogenic tumor that has a distinct clinicoradiographical feature normally suggesting the correct diagnostic. Opinions have varied over the years regarding its nature and behavior, nowadays cementoblastoma is considered an innocuous neoplasm that can be conservatively treated. However, clinicians and oral pathologists must have in mind several possible differential diagnosis that can lead to a misdiagnosed lesion, especially when unusual clinical features are present. The aim of this paper is to report a case of cementoblastoma with uncommon features in a 19-year-old female patient and to discuss its probable differential diagnosis.
Keywords: Cementoblastoma, Odontogenic tumor, Differential diagnosis
Introduction
Cementoblastoma is a rare mesenchymal odontogenic tumor of the jaws, being considered as the unique true neoplasm derived from cementum [1]. The lesion accounts for less than 1–6.2% of all odontogenic tumors [2] and characteristically, it is always attached to the roots of a tooth, most frequently a first inferior molar, usually leading to pain and swelling of the affected region. This neoplasm forms a large mass of cementum or cementum-like tissue on the tooth root [3] and must be distinguished from other pathological conditions that may produce clinical and radiographic features similar to those observed in cementoblastoma [4]. The purpose of this paper is to report a case of benign cementoblastoma that was previously misdiagnosed as fibrous dysplasia, affecting the right superior first and second molars in a 19-year-old female patient and to discuss the possible differential diagnosis of the lesion.
Case report
A 19-year-old caucasian female patient presented to the Service of Buccal Pathology of the João de Barros Barreto University Hospital, Brazil to treatment for a previously diagnosed fibrous dysplasia. The patient's major complaint was a swelling in the posterior region of maxilla and a mild pain, especially during the night that was relieved after taking salicylates (Fig. 1). Nevertheless, our surgical-pathological staff did not have access to the previous radiographies and microscopic exams, therefore, we decided to perform another evaluation of the patient.
Figure 1.
Intra-oral and extra-oral clinical features.
Her medical and family histories were noncontributory and the clinical evaluation revealed a swelling of the buccal and palatal regions. A panoramic radiography and a tomography exam were taken for imaginological examination, revealing a radiopaque mass attached to the lateral portion of the roots of the upper right first and second molars, and a radiolucent periphery could be observed surrounding the tumor (Figure 2, Figure 3).
Figure 2.
Panoramic radiography.
Figure 3.
Gross macroscopic aspect and tomography exam.
An incisional biopsy of the lesion was performed and histologically, the lesion consisted of broad trabeculae of sparsely cellular cementum (Fig. 4A and B). These merged with areas of cemental islands in a vascular stroma with prominent cementoblasts (Fig. 4C). The peripheral zone of the tumor showed characteristic radiating columns of cementum running perpendicular to the surface of the lesion. Hence, the clinical–radiographic aspects associated to the microscopic features suggested a diagnosis of cementoblastoma.
Figure 4.
Microscopic features. (A and B) Broad trabeculaes of sparsely cementum in a vascular stroma, fused to the dental root (Left) (HeE; 10× and 20×). (C) Prominent cementoblasts around the trabeculaes of cementum (HeE, 40×).
Enucleation of the calcified mass with the extraction of the teeth involved was performed under general anesthesia and the lesion was easily differentiated from normal bone (Fig. 5). Macroscopically, a hard ovoid mass of calcified material attached to the roots of the right maxilla first and second molars was obtained (Figure 3, Figure 6). The surgical specimen was sent for pathologic examination that confirmed the diagnostic of cementoblastoma.
Figure 5.
Enucleation of the calcified mass.
Figure 6.
Macroscopic features.
Discussion
Cementoblastoma is a benign odontogenic tumor arising from cementoblasts [4]. It has been described as a benign solitary, slow-growing lesion with unlimited growth potential [1], although there have been reports of aggressive behavior [5]. The last World Health Organization tumors classification has included the condition into odontogenic tumors group [6].
Symptoms may be totally absent [1], but most patients initially present with mild pain and bony swelling in the area of the lesion, leading to expansion and facial asymmetry in a few cases. Patients under 20 years old have been reported as the most affected group [2], [4]. In the present case, we noted a swelling in both buccal and palatal portions of the affected region and the patient used to complain of a mild pain, especially during the night, that was controlled with the administration of salicylates. Her age was in agreement with the expected.
Several authors have stated that there does not appear to be any significant gender or racial predilection [4], however, some studies have shown a slight prevalence of male patients affected by cementoblastoma [2], [7], being white individuals the most affected racial group [2]. Mandible is by far the most common location and the majority of cementoblastomas are associated with a mandibular permanent first molar [4], characterized by being attached to a single root in the molar area, despite some cases have been reported the involvement of multiple roots simultaneously, impacted molars, unerupted teeth [1] and attached to a developing tooth [8]. Unusually, in the present case maxilla teeth are being affected by the neoplasm and the lesion is physically attached to the roots of two upper teeth (teeth 17 and 18) simultaneously, representing a rare presentation of this lesion.
The cementoblastoma often has a pathognomonic radiographic appearance. It appears as a well-defined solitary circular radiopacity with a radiolucent halo, fused to the partly resorbed root(s) of the associated tooth [1], [4], however, mixed-density and completely radiolucent lesions have been reported, depending on its stage of maturation [2].
Depending on the stage of development of the lesion there are several lesions that must be distinguished from benign cementoblastoma (Table 1). Hypercementosis, focal osseous dysplasia, focal sclerosing osteomyelitis, idiopatic osteosclerosis, odontoma, osteoblastoma, osteoid osteoma and fibrous dysplasia must be considered [9]. Regarding histopathological features, cementoblastoma must be differentiated from osteoid osteoma, benign osteoblastoma, or atypical osteosarcoma [5].
Table 1. Clinical and radiographic features of the lesions
| Lesions | Clinical features | Radiographic aspects |
|---|---|---|
| Cementoblastoma | Slow-growing lesion with unlimited growth potential; presence of a mild pain and bony swelling; patients under 20 years old; mandibular permanent first molar; fused to a single root | Well-defined solitary circular radiopacity with a radiolucent halo, fused to the partly resorbed root of the associated tooth |
| Hypercementosis | Usually premolars teeth; adult patients most affected; fused to the roots surface; no associated pain or jaw swelling | Well-defined radiopaque mass fused with the root of a vital tooth with a radiolucent halo |
| Osseous dysplasia | Not fused to the roots surface; asymptomatic; no swelling; presence of a limited growth potential | Correlated with the amount of calcification |
| Focal sclerosing osteomyelitis | Presence of a dental inflammatory stimulus; dental pulp of the involved tooth presents necrosed; absence of swelling; not fused to the roots surface | Radiopaque regions not presenting a radiolucent halo |
| Idiopatic osteosclerosis | Patients from 20 to 40 years old; always assyntomatic; not fused to the roots surface | Radiopaque regions not presenting a radiolucent halo |
| Odontoma | Nonaggressive behavior; young adults patients; posterior region of the jaw; not fused to the roots surface | Well-defined radiopacity with a radiolucent halo with various degrees of radiopacities |
| Endosteal osteoma | Young patients; body of the mandible or the condyle; asyntomatic; no swelling; limited growth potential | Small radiopacity without a radiolucent halo |
| Osteoblastoma | Unlimited growth potential; presence of a mild pain during the night, not relieved with salicylates; not fused to the roots surface | Correlated with the amount of calcification |
| Osteoid osteoma | Presence of a night pain relieved with salicylates; limited growth potential; not fused to the roots surface | Correlated with the amount of calcification |
| Osteosarcoma | Presence of pain and swelling; adult patients; fast volume increase; presence of malignant features | Correlated with the amount of calcification, it may be completely lytic, sclerotic or both, with presence of radiopacity resembling sunrays |
| Fibrous dysplasia | Less than 20 years; female patients; absence of pain; presence of swelling | “Ground-glass” radiographic appearance and loss of lamina dura |
Hypercementosis, representing excessive deposition of cementum around the apex of a tooth, may present as a well-defined radiopaque mass fused with the root of a vital tooth [9]. The lesion is involved by a radiolucent halo representing the normal periodontal ligament and can affect only one tooth, several teeth or can be a generalized process. Premolars are the most affected teeth and the lesion is more often observed in adults than in young patients [10]. Various local and systemic factors have been suggested to be associated to a higher frequency of hypercementosis, such as oclusal traumas, Paget's disease, Gardner's Syndrome and Hyperthyroidism [9], [10]. Differently from cementoblastoma, the radiopaque lesion of hypercementosis is usually smaller, and there is no associated pain or jaw swelling [4], being usually found during routine radiographic examination [9], besides its histopathological features that show a normal cementun tissue being excessively deposited on the root surface [10].
Osseous dysplasia occurring focally in the jaws has been called as focal osseous dysplasia and must be considered as a differential diagnosis for cementoblastoma. It is a reactive or a dysplastic process [11], generally asymptomatic and usually discovered on routine radiographic examination [9]. Differently from cementoblastoma, the lesion is not physically attached to the root surface of the affected tooth, does not cause local swelling and pain and have a limited growth potential, not being recognized as a neoplasm.
Focal sclerosing osteomyelitis (FSO) is characterized by a localized bony sclerotic area associated to the apex of the adjacent tooth [9], [10]. A low-grade inflammatory stimulus, such as chronic periapical inflammation or malocclusion, may be the causative factor of the lesion [9]. In contrast to cementoblastoma, FSO does not show any peripheral radiolucent rim [4], [9], [10] and the dental pulp of the involved tooth presents necrosed or with a pulpitis with no signs of clinical swelling [10], while cementoblastoma is not associated to a pulpitis and clinical swelling is normally observed.
Idiopatic osteosclerosis are radiopaque regions of dense bone production associated to no specific cause, mainly affecting patients from 20 to 40 years old [10] and in contrast to cementoblastoma the condition is always assyntomatic, not presenting a radiolucent halo around it, is not fused to the roots surface of a tooth and microscopically only a higher deposition of normal bone tissue can be observed.
Odontomas are hamartomas composed of various dental tissues, i.e., enamel, dentin, cementum and sometimes pulp. They are slow-growing, benign lesions showing nonaggressive behavior, usually being discovered incidentally in children or young adults during routine radiographic examination [10]. Complex odontomas tend to occur in the posterior region of the jaw [12] and radiographically, it presents as a well-defined radiopacity with a radiolucent halo typically surrounding the tumor, similar to cementoblastoma. Nevertheless, variations in the degree of radiopacity due to the presence of various dental tissues may facilitate differential diagnosis from other radiopacities [4], [9], [12] and it is not fused to the adjacent tooth [4].
Endosteal osteoma is a benign tumor of the jaws, most commonly encountered in young patients usually involving the body of the mandible or the condyle [9]. It is generally asyntomatic, not causing swelling of the region, like cementoblastoma does. The dense bony overgrowths can hardly be considered neoplastic because their growth potential is severely restricted [5], [10], [13]. Radiographically, an endosteal osteoma presents as a small radiopacity without a radiolucent rim, different from benign cementoblastoma [9], [10].
Osteoblastoma is a benign neoplasm of bone characterized by the proliferation of numerous plump osteoblasts and bone trabeculae embedded by a well-vascularized fibrous connective tissue stroma [14]. It has an unlimited growth potential and radiographically, the degree of opacification of the lesion correlates with the amount of calcification noted histologically, as well as cementoblastoma does [10], [14]. According to Unni [5] there is no histopathological difference between cementoblastoma and osteoblastoma and we can only differ both lesions by the attachment or not to the tooth root surface, present in the cementoblastoma and absent in the osteoblastoma. In addition, osteoblastoma shows the typical mild pain during the night, however, it cannot be relieved with salicylates [5].
Despite osteoid osteoma also presents a common night pain relieved by salicylate intake like our case does, this lesion has a limited growth potential not exceeding 1
cm, besides not being attached to the roots surface, differing this condition from cementoblastoma [5], [14].
Histopathologically, conventional osteosarcoma may have microscopical areas resembling a cementoblastoma [5], [6], however, some aspects such as the sharp circumscription with no permeation of surrounding bone [5] and the absent of atypias in the cementoblastoma, always associated to its benign clinical and radiographic features can guide us to the distinction from osteosarcoma.
Fibrous dysplasia is a rare disease predominantly found in the first and second decades of life and is more common in female patients [10]. The bone matrix is replaced by the cellular fibrous and connective tissue resulting in abnormal and unstable bone formation with less mineralization. The lesion may cause several problems, such as facial asymmetry, mandibular enlargement, chronic sinusitis, recurrent headache, nasal obstruction, conductive-type hearing loss, and dental problems including malocclusion [15]. This case report was previously misdiagnosed as fibrous dysplasia, what would lead to an erroneous aesthetic osteotomy as the surgical procedure to be performed, resulting in recurrences. However, the absence of the typical “ground-glass” radiographic appearance and loss of lamina dura, the presence of a radiolucent rim around the lesion and the complaint of pain led us to suggest the possibility of not being a fibrous dysplasia.
In conclusion, cementoblastoma is a rare odontogenic lesion that when arising in a different location from the inferior molar region can offer several diagnostic difficulties. Therefore, in order to perform a correct diagnostic, in these cases, the clinical exam associated to the imaginological features and the histopathological exam must be carefully evaluated.
References
- . Benign cementoblastoma: a case report. Med. Oral Patol. Oral. Cir. Bucal. 2006;11:E483–E485
- . Cementoblastoma: an innocuous neoplasm? A clinicopathologic study of 44 cases and review of the literature with special emphasis on recurrence. Oral Surg. Oral Med. Oral Pathol. Oral Radiol. Endod. 2002;93:311–320
- . Contemporary Oral and Maxillofacial Pathology. St Louis: Mosby; 1997;pp. 144–145
- . Benign cementoblastoma: a case report. J. Can. Dent. Assoc. 2001;67:260–262
- . Dahlin's Bone Tumors. General Aspects and Data on 11,087 Cases. Philadelphia: Lippincott-Raven; 1996;pp. 121–142
- . Pathology & Genetics: Head and Neck Tumours. Geneva: WHO; 2005;
- . Benign cementoblastoma involving multiple maxillary teeth: report of a case with a review of the literature. Oral Surg. Oral Med. Oral Pathol. Oral Radiol. Endod. 2004;97:53–58
- . An unusual recurrent cementoblastoma associated with a developing lower second molar tooth: a case report. J. Oral Maxillofac. Surg. 2007;65:2080–2082
- . Globular radiopacity around the apex of an impacted maxillary third molar. Oral Surg. Oral Med. Oral Pathol. Oral Radiol. Endod. 2007;103:594–598
- . Oral and Maxillofacial Pathology. Philadelphia: Saunders; 2002;pp. 553–571
- . Focal cemento-osseous dysplasia involving a mandibular lateral incisor. Int. Endo. J. 2003;36:907–911
- . Large erupting complex odontoma: a case report. J. Can. Dent. Assoc. 2007;73(2):169–172
- . Peripheral osteoma of the mandible: case report and review of the literature. J. Craniomaxillofac. Surg. 2005;33:276–281
- . Osteoblastoma of the maxilla and mandible: a report of 24 cases, review of the literature, and discussion of its relationship to osteoid osteoma of the jaws. Oral Surg. Oral Med. Oral Pathol. Oral Radiol. Endod. 2006;102:639–650
- . Fibrous dysplasia of the temporal bone and maxillofacial region associated with cholesteatoma of the middle ear. Auris Nasus Larynx. 1999;26(1):79–81
PII: S1871-4048(08)00028-2
doi:10.1016/j.pedex.2008.04.001
© 2008 Elsevier Ireland Ltd. All rights reserved.
Volume 3, Issue 4 , Pages 182-187, December 2008
