Huge ossifying fibroma maxilla.

Maxillofacial fibro-osseous lesions comprise a group of face and jaw disorders characterized by the replacement of bone by a benign connective-tissue matrix with varying amount of mineralized substances. Fibro-osseous lesions of the maxilla are not an uncommon tumor. Majority of the lesions with fibrous and osseous components include ossifying fibroma, fibrous dysplasia, cemento-ossifying fibroma, and cementifying fibroma. We present a case of 15-year-old female with huge fibroosseous lesion which was treated with total maxillectomy via a Weber-Ferguson approach. Histopathology established that fibroosseous lesion as an ossifying fibroma.

INTRODUCTION

Fibro-osseous lesions are group of lesions characterized histopathologically by the presence of fibrous stroma with varying amount of mineralized material resembling bone or cementum.[12] Fibro-osseous lesions of the maxilla are not an uncommon tumor. Majority of the lesions with fibrous and osseous components include ossifying fibroma, fibrous dysplasia, cemento-ossifying fibroma, and cementifying fibroma with other less common lesions include focal sclerosing osteomyelitis, florid osseous dysplasia, periapical dysplasia, proliferative periostitis of garre, and osteitis deformans. Fibro-osseous lesions other than fibrous dysplasia arise from a layer of fibrous connective-tissue surrounding the roots of teeth. This layer contains multipotential cells that are capable of forming cementum, lamellar bone, and fibrous tissue.[34] The differential diagnosis of fibro-osseous lesions includes osteoblastoma, osteoid osteoma, chronic sclerosing osteomyelitis, ameloblastoma of maxillary sinus, Pindborg tumor, calcifying odontogenic cyst (Gorlin cyst), odontogenic myxoma, osteogenesis imperfecta, and Paget's disease.[5]

CASE REPORT

A 15-year-old woman was presented to us with complaints of gradually progressive swelling left side face with upward and outward bulging of the left eye for 6 years. She also had nasal obstruction and watering from the left eye for 1 year [Figure 1]. The patient had no complaint of pain over the face or during eye movements. Her family and past medical history were insignificant. The physical examination showed left side maxillary enlargement with marked upward and outward displacement of left eyeball. Oral cavity examination revealed obliterated gingiva-buccal groove, displaced, and misaligned teeth with normal oral mucosa and mouth opening. On palpation, swelling was hard in consistency with no fluctuation. There were no signs of inflammation over the face with an irregular surface and free overlying skin. No cervical lymphadenopathy was noted. A computed tomography (CT) scan showed a mixed density mass with diffuse scattered calcification occupying and expanding the left maxillary antrum with marked displacement of left eyeball [Figures 2 and 3]. A tissue sample was obtained for histopathological study which showed a lamellar bone with osteoblastic rimming with subepithelial zone showing fibrous element [Figure 4]. A diagnosis of ossifying fibroma was made, and the patient underwent complete surgical resection via Weber-Ferguson approach [Figure 5].

Figure 1

Patient with a left maxillary enlargement with gross disfigurement and marked proptosis

Figure 2

Computed tomography scan axial section shows a well-defined lesion with radiolucent and radio-opaque foci

Figure 3

Computed tomography scan coronal section shows a well-defined lesion with radiolucent and radio-opaque foci

Figure 4

Microphotograph showing fibrous element along with areas of dense ossification as well as psammomatous calcification (H and E, ×10)

Figure 5

The surgical specimen (gross appearance)

DISCUSSION

Ossifying fibromas and fibrous dysplasias are the two major groups of benign fibro-osseous lesions that involve the maxilla[6] leading to significant cosmetic and functional disturbances. Because of peculiar patterns of disease progression, it is important to distinguish between the two. Ossifying fibroma is well-circumscribed, slow growing, and sharply defined margins with a radiolucent peripheral component. The etiology of ossifying fibroma remains unknown, and it is considered a tumor arising from periodontal membrane. The lesions are most commonly seen in the third and fourth decades of life with female preponderance. The lesion is generally asymptomatic until the growth produces a pain, paresthesias, and facial asymmetry. Ossifying fibroma most commonly involves mandible and extension of tumor mass into the ramus of the mandible and involvement of the inferior border may lead paresthesia of the inferior alveolar nerve. Involvement of maxilla causes cortical expansion with obliteration of the gingivobuccal sulcus, extension into the nasal cavity, and orbital floor leads to epistaxis and epiphora. On CT, ossifying fibroma appears as a solitary radiolucent cyst-like mass with minimal or absent internal calcified components in early stage while it is radiodense in late stage.[67] Histopathologically, ossifying fibroma is composed of lamellar bone with prominent osteoblastic rimming in dense fibrous stroma. The differential diagnosis having radiopacities within a well-defined radiolucent mass includes chondrosarcoma, osteosarcoma, fibrous dysplasia, squamous cell carcinomas, odontogenic cysts, calcifying odontogenic cysts, and calcifying epithelial odontogenic tumors (Pindborg tumors). The well-defined border of the ossifying fibroma helps differentiate it from the aggressive sarcomas and carcinomas. Fibrous dysplasia has a characteristic “ground glass” appearance not seen in the ossifying fibroma. Differentiation of ossifying fibroma and fibrous dysplasia may be difficult due to marked histological and radiological overlapping. There is radiological overlapping among ossifying fibroma, Gorlin cysts, and Pindborg tumors necessitating the final diagnosis on the basis of histologic appearance. Pindborg tumors have a high association with impacted teeth.[8] Ossifying fibroma should be completely enucleated from the surrounding bone because of high chances of recurrence.[19]

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Conflicts of interest

There are no conflicts of interest.