Maxillofacial Cemento‐Ossifying Fibroma: A Rare Case Report

ABSTRACT

Cemento‐ossifying fibroma is a relatively rare lesion affecting the jaws, especially the anterior mandible. The most common clinical presentation is swelling. Diagnosis based on clinical observation only is challenging. Radiological images and histological findings can be misleading due to similitudes with other osteo‐fibrous lesions. We report a rare case of a 22‐year‐old female patient who presented with a painless mass in the upper right maxillary region that has been developing for 10 years. On examination, this tumor was bulky, ulcerated, disfiguring, hard to the touch, and occupying the whole of nasal, malar and maxillary regions. CT scan showed a well‐circumscribed mass spanning from the right palatal and maxillary bones with mixed density content of soft tissue and diffuse calcified foci. The mass harbored dense bundles of fibrocollagenous connective tissue in a cellular stroma on histopathological examination. After a provisional diagnosis of osteoblastoma based on clinical and computed tomography features, the final diagnosis was based upon correlation of histopathological characteristics with both clinical and radiographic findings. A one‐time surgical resection was performed to enucleate the tumor. This was followed by curettage. The lateral maxillary location of this tumor makes it unusual. Henceforth, a proper conclusive diagnosis of cemento‐ossifying fibroma should be obtained from a histopathological study, in conjunction with clinical and radiological findings, and particular traits that the patient may present.

Key Clinical Message

Myxofibrosarcoma is a rare, aggressive soft tissue tumor with a high recurrence rate. Early diagnosis, complete surgical excision, and long‐term follow‐up are crucial to improving outcomes. This case highlights the diagnostic challenges and the importance of multidisciplinary management in atypical tumor presentations.

1. Introduction

Cemento‐ossifying fibroma (COF), as per the World Health Organization's (WHO) 2022 classification of head and neck tumors, is a well‐demarcated neoplasm which consists of fibrous tissue containing varying amounts of mineralized material resembling bone and/or cementum [1]. It is a benign fibro‐osseous lesion and is derived from the multipotential mesenchymal blast cells of the periodontal ligament [2].

COF was already defined as a benign mesenchymal odontogenic tumor in the 2017 WHO classification. However, it was described under the category of fibro‐osseous lesions [3], but is now an integral part of the benign mesenchymal odontogenic tumors in the 2022 classification, completely isolated from the non‐odontogenic juvenile trabecular (JTOF) and psammomatoid types (POF) [1].

COFs occur mostly in between the second and fourth decades of life with a definitive female predilection in the ratio of 4:1 [4]. However, they may be present in children and adolescents, as well as in older adults [5, 6]. The mandible—preferentially in the molar region—is more involved than the maxilla [7], albeit other cranial and facial bones such as the frontal, periorbital, sphenoid, ethmoid and temporal bones are also affected [8]. The tumor is termed central COF when lesions are located intraosseously, whereas peripheral COF refers to extraosseous lesions, or those appearing on the outer soft tissue [9]. The tumor is well demarcated by a teeny sclerotic shell of bone. Unpredictably, it may either show a slow growth or appear to be locally aggressive with cortical damage and involvement of several nearby anatomical structures [10]. Histologically, the neoplasm is composed of a proliferating fibrous tissue and osseous particles containing bony strands and cementum‐like material [5]. This lesion is thought to occur in reaction to low‐grade irritations such as trauma, calculus, plaque, masticatory forces, ill‐fitting dentures and poor‐quality restorations [11].

Clinically, OF presents as a spherical or ovoid, generally slow‐growing, painless and expansive jaw bone mass that may displace the roots of adjacent teeth and occasionally causes facial deformity and/or functional discomfort [12]. Definitive diagnosis requires correlation of clinical, radiographic, and histopathological findings [13]. The treatment consists of surgical excision with enlarged resection depending on the size and location of the lesion [10, 14].

For an optimal management of COF, an accurate diagnosis is necessary. Clinical presentation is not unique, and the radiological patterns depend on the degree of mineralization of the tumor. The clinician is then confronted by the overlapping patterns of the broad spectrum of fibro‐osseous tumors, and the presence of unusual patterns makes the diagnosis even more challenging. We present a rare case of COF in a 22‐year‐old female patient in the lateral maxilla, which is an unusual site of occurrence.

2. Case History/Examination

A 22‐year‐old female patient was referred to the Department of Oral and Maxillofacial Surgery with a painless swelling in the upper right region of the jawbone since 10 years. The swelling sprouted as a small painless nodule when the patient was 12 and grew with time. As the swelling was increasing, only the vision was shielded, but the deglutition and breathing were not affected. Mastication on the right side and speech were also affected. No pain, fever, or any comorbidity was reported. There was no history of previous similar swelling, toothache, numbness, trauma, surgery, or radiotherapy. Although the patient was from a low socio‐economic status, her parents and siblings were all well. There was no similar swelling in the family.

The patient's general condition was otherwise good with fair nutritional status. Extraoral examination showed a bulky, dome‐shaped, and well‐defined swelling extending over the right hemi‐maxilla with a frontward expansion causing facial disfigurement. The dome of the swelling was budding and ulcerated. The palpation of the swelling revealed a bony hard consistency, with no tenderness elicited. The mass was immobile on mobilization and measured approximately 40 cm × 12 cm in size (Figure 1). On intraoral examination, all the teeth of the right hemi‐maxilla were buried under the swelling.

FIGURE 1.

Frontal view of a budding ulcerated tumor located in the right of the upper jaw, disfiguring the face.

There was no palpable lymphadenopathy. Neurological examination, as well as respiratory, digestive, and urogenital explorations, did not reveal any abnormality.

3. Differential Diagnosis, Investigations and Treatment

A maxillofacial computed tomography (CT) was performed and revealed a well‐circumscribed exuberant mass in the right facial region, spanning from the right palatal and maxillary bones and extending into the right malar bone. Detailedly, an osteoforming excrescence with a regular margin and a mixed density content made of soft tissue and diffuse scattered calcified foci, with teeth 21–28 engulfed in the mass (Figure 2A). Also, the CT image showed a mass effect of the tumor causing left deviation of the nasal septum, with a narrowed osteo‐meatal system, yet preserving its anatomical structure (Figure 2B).

FIGURE 2.

(A) CT scan showing a well‐circumscribed exuberant tumor mass emerging from palatal and maxillary bones, with a mixed density, comprising diffuse areas of calcification. A sclerotic rim is noted. (B) Panoramic view of a CT scan shows the tumor involving the right maxilla, extending to the malar bone and pushing on nasal septum which is then deviated to the left, with an entire (narrowed) osteo‐meatal system.

A provisional diagnosis of osteoblastoma was recorded, with fibrous dysplasia and ossifying fibroma being considered in the differential diagnosis.

An excisional biopsy (16 × 10 cm) of the tumor was performed, and the histopathological examination revealed a well‐circumscribed fibrous tissue containing dispersed foci of calcification. The mass harbored dense bundles of fibrocollagenous connective tissue in a cellular stroma (Figure 3A). The matrix was formed by interconnected trabeculae of mature lamellar bone with fibroblastic rimming (Figure 3B). No atypical cells nor mitosis were observed, and the lesion also showed an ulcerated stratified squamous epithelium. On the basis of histopathological findings, and correlating them with clinical and radiological features, a final diagnosis of (peripheral) cemento‐ossifying fibroma was established, excluding JTOF and POF subtypes.

FIGURE 3.

(A) Histopathological picture showing dispersed areas of dense mineralization foci in a fibrocellular stroma. (B) Histopathological picture showing branching trabeculae of mature bone bordered by a fibroblastic tissue.

As management, a surgical resection of the tumor was performed, followed by curettage.

4. Conclusion and Results (Outcome and Follow‐Up)

Postoperative period was uneventful, and a clinical follow‐up plan was established for review after 3 months, 6 months, and 1 year after surgery.

5. Discussion

Cemento‐ossifying fibroma is a rare, well‐demarcated benign fibro‐osseous tumor in which normal bone tissue is replaced by fibrocellular tissue and fibroblasts, with formation of varying amounts of mineralized material [15]. It is worth noting that peripheral cemento‐ossifying fibroma is not considered the peripheral counterpart of cemento‐ossifying fibroma, but rather as a reactive gingival hyperplasia with mineralization [16].

Two other variants, namely juvenile trabecular ossifying fibroma and psammomatoid ossifying fibroma, which were once described under the group of fibro‐osseous lesions together with cemento‐ossifying fibroma in the World Health Organization 2017 classification of head and neck tumors, are now individualized from the odontogenic cemento‐ossifying fibroma and separately described as non‐odontogenic benign fibro‐osseous lesions in the 2022 edition [17].

The neoplasm originates from periodontal ligament and affects more the mandible than the maxilla, preferentially in the premolar‐molar region of the mandible. However, other areas of the facial skeleton can be involved [18]. In the case presented in this paper, the tumor was located in the right maxillary and palatal bones, a rare location in contradiction with commonly described sites of occurrence.

According to the literature, cemento‐ossifying fibroma is more prevalent in the third and fourth decades of life, with a remarkable female predilection. While juvenile trabecular ossifying fibroma has a peak of incidence in the 1st and 2nd decades, psammomatoid ossifying fibroma has a predilection for the 2nd–4th decades [19].

Marx and Stern postulated that OF appears frequently in the jaws, presumably because these lesions involve an extensive mesenchymal cellular induction into bone and cementum, needed in odontogenesis. Henceforth, when an error occurs in the tissue induction process, a cemento‐ossifying fibroma may develop in the jaw bones. Periodontal ligament contains pluripotential cells that are able to form bone, cementum, and fibrous tissue. This may explain that some fibro‐osseous lesions originate from the periodontal ligament [20].

Although the tumor is known to be slow‐growing and finely demarcated from adjacent bone, some lesions may overgrow to reach massive size, causing significant esthetic and functional deformity [15]. This case was characterized by important esthetic distortion involving the face of the patient.

Even though the definite pathogenesis is still unknown, some information from the literature suggests that trauma‐induced stimulation may play a key role [21]. Usually, cemento‐ossifying fibroma presents clinically as a single, painless, expansive, slow‐growing, spherical or ovoid mass that is generally asymptomatic. However, in some cases, patients present with complaints of pain, paresthesia, nasal obstruction, esthetic deformity, orbital damage, or functional impairment [12, 22]. Unlike psammomatoid ossifying fibroma, the juvenile trabecular variant is notable for its rapid expansion [19].

One of the clues to the diagnosis involves radiographic evaluation—particularly computed tomography—that shows a mixed density mass comprising both soft tissue density with diffuse scattered calcification. Basically, three radiological stages are characterized; that is, early, mixed, and mature stages.

In the early stage, cemento‐ossifying fibroma shows a radiolucent lesion pattern due to predominant fibrous tissue proliferation. With tumor evolution, the mixed stage is portrayed by the emergence of patches of calcification, giving the lesion a mixture of radio‐opacity and radiolucency. Lately, once the mature stage is reached, the mass appears completely radio‐opaque because of the presence of advanced bony calcifications and cementum. The same features are described in other fibro‐osseous lesions including juvenile trabecular ossifying fibroma and psammomatoid ossifying fibroma [23].

In this case, radiographic patterns were suggestive of the mixed stage, with a mixture of radio‐opaque calcification foci and radiolucent fibrocollagenous tissue.

Histological examination of a tumor's biopsy reveals cellular connective tissue with collagen fibers and fibroblast bordering bony trabeculae and osteoid. The tumor's matrix can either be trabecular with cellular inclusions and osteoblastic rimming or contain tiny rounder and acellular matrix similar to cementum [5].

In the presented case, histological examination revealed trabeculae of lamellar bone matrix with osteoblastic rimming and hypercellular fields with interspersed calcification areas. Calcified areas were formed of cementum‐like material, and fibrocollagenous cellular elements were aligned in different patterns. These patterns are correlated with cemento‐ossifying fibroma typical lesions.

In juvenile trabecular ossifying fibroma, apart from common fibro‐osseous characteristics, specific lesions include a single aggregate of curvilinear strands of oedema, hemorrhage, as well as osteoclasts and pseudocystic degeneration [19].

On the other hand, histological study of psammomatoid ossifying fibroma reveals hypercellular spindle cell stroma harboring multiple spherical‐shaped and uniform ossicles called “psammomas” [24].

Due to overlapping clinical and histopathological characteristics, this rare neoplasm may pose a serious diagnostic conundrum to the clinician and the pathologist. Hence, an accurate diagnosis requires a proper correlation of the patient's history, clinical, radiographic, and histologic findings [18]. With cemento‐ossifying fibroma being a relatively slow‐growing tumor, as a consequence, the superjacent cortical bone layer and mucosa stay intact while the tumor is developing, and thus could be diagnosed many years later [14].

It is a tumor with a good prognosis. However, recurrences, though uncommon, have been reported in some cases [4]. Complications may include sinus obstruction, facial deformity, infection, proptosis, and intracranial complications [25]. The treatment implies a surgical excision with extended resection depending on the volume and location of the tumor, and this must be followed by curettage. It has been reported that radiotherapy is ineffective [13]. The postoperative management can be optimized with a combination of clinical and x‐ray follow‐up for a longer period of time. Unfortunately, the lack of or short follow‐up time in reported cases should be underlined [10]. In this case, the patient was only clinically followed up for 1 year, which is not enough and can therefore be considered a limitation. Future studies could address this issue by combining postoperative clinical and radiological monitoring over a longer time span.

6. Conclusion

Ossifying fibroma is a rare neoplasm commonly located in the premolar‐molar region of the mandible. Clinical presentation is not specific, and radiological images mimic other lesions. The diagnosis requires a combination of clinical, radiographic, and histologic features. The treatment is based on surgical resection. The patient should be followed up because of a probable risk of recurrence.

Author Contributions

Alix N. Kamina: conceptualization, supervision, writing – original draft, writing – review and editing. Elisée Ntambua Mbombo: methodology, writing – original draft, writing – review and editing. Patrick Badibanga: writing – original draft, writing – review and editing. Christian Tague: methodology, visualization, writing – original draft, writing – review and editing. Pascal Lutumba: writing – original draft, writing – review and editing. Criss Koba Mjumbe: methodology, supervision, writing – original draft, writing – review and editing.

Funding

The authors have nothing to report.

Disclosure

No artificial intelligence was used in generating the manuscript.

Consent

The patient provided written informed consent for the publication of clinical details, examination results, and images. A signed consent form is in the possession of the authors and can be provided to the publisher upon request.

Conflicts of Interest

The authors declare no conflicts of interest.

Data Availability Statement

The authors have nothing to report.