Juvenile Trabecular Ossifying Fibroma of the Maxilla: a Case Report.

INTRODUCTION: Juvenile ossifying fibromas are uncommon benign tumors. Their aggressiveness added to their high tendency to recur, provoke real diagnostic and therapeutic challenges for the dental practitioner and make a postoperative follow-up over the years indispensable. CASE REPORT: In this report, we present a case of a seven-year-old girl presented with a swelling in the face at the upper right maxillary region. After clinical, radiological, and histopathological examinations the diagnosis of trabecular juvenile ossifying fibroma was made. The lesion was surgically excised and followed up for two years with no evidence of recurrence.

1. Introduction

Juvenile ossifying fibromas (JOFs) are rare benign fibro-osseous tumors (1). They usually appear under the age of fifteen (2), and concern the facial bones with possible intracranial and orbital extensions (3). Generally, JOFs are asymptomatic, aggressive and of osteolytic nature (4).

Due to their high recurrence rate, early diagnosis, suitable treatment and a long-term follow-up are essential (5).

Histologically, and like in all the ossifying fibromas, the normal bone is replaced by a fibrous cellular stroma containing mineralized bone trabeculae and cementum-like material (4, 6).

According to their prototype of mineralization, JOFs have been classified into two types: the psammomatous characterized by small uniform spherical ossicles resembling psammoma bodies located mainly around paranasal sinuses and orbits, and the trabecular distinguished by fibrous trabeculae and usually affecting the jaws (4).

This report describes a case of a maxillary trabecular JOF of a seven-year-old girl removed surgically and followed up for two years without evidence of recurrence.

2. Case report

A seven-year-old girl presented to our specialized pediatric dentistry office referred from her dentist for a persistent firm swelling localized at the upper right maxillary region.

Medical and physical examinations revealed a healthy girl with no extra-oral findings except the facial asymmetry. Intra-orally, a painless tumefaction of hard consistency obliterating the vestibule of the right maxilla and extending from the tooth # 53 to the distal of the tooth # 16 was detected (Figure 1).

Figure 1

A well-defined swelling obliterating the vestibule and extending from the tooth # 53 to # 16.

The overlying mucosa was normal in color and texture. On palpation, no regional lymphadenopathy was noticed.

The panoramic radiograph, done previously by her dentist, showed a well-defined radiolucent lesion in the right maxilla and absence of the tooth # 54 which was extracted as an attempt of treatment for her condition (Figure 2).

Figure 2

A panoramic radiograph showing a well-defined radiolucent lesion in the right maxilla and absence of tooth # 54.

In order to assess the bone and to evaluate the extension of the lesion, a cone-beam computed tomography (CBCT) radiography was requested.

The CBCT radiograph showed a well circumscribed mixed image, starting distal to the tooth #53 till the mesial of the # 55, and from the crestal edge till the germ of the permanent canine with a diffuse border containing fine radio-opaque trabeculae with a buccal, palatal, and crestal expansion of the bone; a disruption of the buccal bone was also noticed. The image of the right sinus was normal (Figure 3).

Figure 3

A CBCT radiograph showing a mixed image extending from # 53 to # 55 and from the crestal edge till the germ of the permanent canine; a diffuse border contains fine radio-opaque trabeculae with a buccal, palatal, and crestal expansion of the bone with disruption of the buccal bone.

An incisional biopsy was performed and sent for histopathologic assessment.

Microscopic examination showed a proliferation of fusiform cells with regular nuclei arranged in bundles and storiform pattern associated with multinucleated giant cells. Within these irregular strands, mineralized pieces in the form of trabeculae were found. The stratified squamous epithelium surface showed moderate acanthosis and hyperkeratosis (Figure 4).

Figure 4

Histopathological section showing mineralized pieces in the form of trabeculae of woven bone.

The histological diagnosis of trabeculae juvenile ossifying fibroma was made.

The tumor measuring approximately 1.8 x 2.5 cm was surgically excised under general anesthesia via intra-oral approach. During the procedure, the teeth # 53 and # 55 were removed (Figure 5).

Figure 5

One week postoperative intraoral view (the stitches in place).

Post-operative recovery was without complications, and the patient was discharged from the hospital 48 hours following the surgery.

Histopathological results of the excisional biopsy were consistent with that of the incisional one.

The patient was followed for two years, once every six months. She remained recurrence-free clinically and radiologically (Figure 6).

Figure 6

A panoramic radiograph showing new positions of the germs of the teeth # 13, #14, and #15.

3. Discussion

Juvenile ossifying fibromas are rare aggressive fibro-osseous tumor arising in the craniofacial bones (2).

Usually, JOFs occur under the age of fifteen without any significant gender predilection (5, 7).

Clinically, JOFs are mostly asymptomatic with slow or rapid development leading to facial asymmetry (8).

As for the radiological aspect, JOFs can be seen as uni- or multilocular radiolucencies/mixed radiolucencies (9); rare root resorption can be observed (4).

Cone-beam computed tomography assessment may show well-defined sclerotic borders with a variable amount of calcifications (10).

Histologically, JOFs are lesions characterized by cell-rich fibrous tissue with giant cells and bands of cellular osteoid trabeculae (11).

Juvenile ossifying fibromas are of two types. One is characterized by spherical ossicles, the psammomatoid, and the second less commonly reported, the trabecular, distinguished by trabeculae osteoid and woven bone as seen in our case (4).

Many bone pathologies usually found in the region may constitute a differential diagnosis challenge for JOF. Fibrous dysplasia remains the most prominent condition (1, 2, 12); it can be ruled out as it typically shows normal marginal bone with less cellular stroma and an important amount of lamellar bone instead of woven one (13).

Cemento-ossifying fibroma, a histological variant of JOF, can also be considered; however, giant cells which are evidently found in JOFs are not present in cement-ossifying fibromas (14). Cementoblastoma, osteoblastoma, osteosarcoma, and others entities must be separated as well when diagnosing JOFs (1, 12); this type of separation must be made with the aid of clinical, radiological and histological examinations.

The treatment of JOFs remains controversial. Complete resection, conservative local excision, or enucleation with curettage, are among the treatment techniques (15-17). Abuzinad and Alyamani (2) suggested that conservative management with less aggressive approach must be considered the treatment of choice of JOFs. The same was proposed by Slootweg and Müller (18) who recommended conservative surgery; for them, there are no differences in the results between the JOFs that had limited surgical excision and those removed with major surgery.

On the other hand, Waldron (19) stated that the local excision/curettage of the lesion is the best treatment of JOFs. However, many other authors reported a high recurrence rate after conservative or mini-invasive treatment (in 30–56% of cases) (15, 20, 21), and thus, a complete surgical resection remains the preferred line of treatment (1, 5, 12, 22).

It is to be noted that whatever the surgical technique was, a long-term postoperative surveillance is essential (1, 2, 7, 12, 23). In our case, we have presented a trabecular JOF localized in the right maxilla of a seven-year-old girl. After histological and radiological confirmations, a complete surgical resection was performed with no recurrence till date.

4. Conclusion

Juvenile trabecular ossifying fibroma is a rare tumor with a rather high risk of recurrence. A careful evaluation of the clinical, radiological, and histological components of this lesion is needed to surmount the diagnostic and therapeutic challenges connected with it. Furthermore, its early diagnosis and adequate treatment consisting in a complete surgical excision followed by long-term follow-up of the patient is indispensable.