Introduction:
Ossifying fibroma or OFs are benign fibro-osseous lesions (pathology on bone and fibrous tissue) or tumors of the head and neck regions. These were initially described by Menzel in the year 1872. These benign tumors are unique, and rare and hold the scope for turning into aggressive and possibly malignant or cancerous tumors of the the head and neck regions. Specifically, when they involve the parts of the midface or the paranasal sinuses of the face. OFs manifest clinically mainly as painless slow-growing benign jaw tumors. The involvement of the lower jaw or mandibular OFs is more common. In the cases of extramandibular lesions such as midface or paranasal sinus tumors, these may often show increasingly aggressive behavior and rapid growth with easy intracranial involvement or access into the skull base. Computed tomography (CT) is the preferred modality of choice for detecting these tumors. Radiologically, these lesions are seen as well-defined unilocular radiolucencies of the lower jaw or the region affected in the head and neck on a CT scan revealing several scattered radiopaque foci.
CT scanning reveals hyperdense masses, necessitating a direct surgical approach by either the maxillofacial surgeon or the oncologist, specifically through the transnasal endoscopic resection, a commonly performed procedure. Following histopathological examination, if the confirmed diagnosis is OF, the maxillofacial surgeon or the oncologist will oversee the surgical and post-surgical tumor management accordingly.
What Is the Etiology of Ossifying Fibroma?
The etiology of OF tumors is mostly unknown in medical literature, but these are more often attributed to their origin as developmentally odontogenic tumors and they might even have a traumatic origin aspect to them. Ossifying fibroma tumors, when occurring in other parts of the body are more commonly seen in children and the tibia (shin bone) and fibula (calf bone) region (in children aged 10 years or younger as documented in medical literature).
However, a majority of these are rare and challenging complex tumors that usually occur only in the head and neck regions, with a higher incidence in young adult individuals. The median age group affected by OFs is between 20 to 30 years with the involvement of the head and neck regions, the mid-face or the paranasal sinuses, sino nasal tracts, or the upper or lower jaw commonly involved. Ossifying fibromas, benign tumors that develop in the mandible, are frequently found in the lower jaw, with a prevalence ranging from 62 to 89 percent among patients. Women may be affected more commonly than men with a female-to-male incidence ratio of 2:1. Ossifying fibromas specifically affecting the sinonasal tract would occur between the third to fourth decade of life in Individuals with no familial patterns or hereditary inheritance according to current medical research. The involvement of the sinonasal tract is also considered extremely rare.
What Are the Complications of Ossifying Fibroma?
The common complications in extensive or untreated OFS for a long period are as follows :
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Sudden or gradual onset of blindness in the patient.
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Orbital cellulitis (Infection of the tissue in the eye cavity).
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Orofacial cysts (cysts in the oral cavity and face).
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Intracranial extension causes meningitis (inflammation of the covering of the nervous system), cerebritis (infection of the cerebrum of the brain), and pneumocephalus (the presence of air in the intracranial space) disease that would possibly occur as a sequel.
How to Manage Ossifying Fibroma?
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En-bloc tumor resection and curettage of lesions are the treatment of choice for mandibular jaw tumors.
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The operative procedure that is usually performed as a gold standard or standard surgical procedure of choice is the trans-nasal endoscopic (endoscopic surgery through the nose) approach. Due to the proximity of ossifying fibroma lesions to the skull base and the attachment to the portion of the lamina papyracea (a paper-thin bone in the eye cavity), surgical complications may often arise when an en-bloc resection is considered by surgeons. In such severe cases, the fibroma lesions are removed in several fragments by the surgeon. Histopathological examination of OFs shows an abundance of irregularly shaped immature woven bone cells that are in turn partially surrounded by an osteoblastic bone layer. These cells are further characteristically enclosed within fibrous stroma or connective tissue. These histopathology findings are consistent with that of the diagnosis of ossifying fibroma by the oral pathologists.
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One other method for managing sinonasal OF is endoscopic resection. These are options only for highly tactile and expert maxillofacial surgeons who can ensure long-term successful post-operative outcomes functionally.
The advantages of endoscopic resection are the operator's direct visualization, easy power of magnification, no scope for causing any external injuries, and decreased patient morbidity. Complications of these surgical management strategies are possible skull base injuries. Hence great care should be taken by the neurosurgeon to prevent any resultant cerebrospinal fluid (CSF) leakage from the approach to skull base lesions. However, despite a CSF leak, the surgeon can still repair the leaks endoscopically within the same sitting. The craniofacial surgical approach for ossifying fibromas similarly has become one of the other commonly accepted surgical methods for treating extensive, disseminated, and large tumors that have breached the cranium or the anterior cranial fossa and have potency for intracranial involvement (tumors that extend into the cranial cavity).
What Are the Concerns of Post-operative Management?
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Endoscopic evaluation should be done or considered by the maxillofacial surgeon post-surgery, especially of the nasal cavity. It is important to check whether there is only partial or complete wound healing in the affected patients post three months of surgery. Six monthly endoscopic evaluations and regular follow-ups are advisable for improving long-term functions and preventing recurrence.
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The most unique and dangerous part of these tumors is that radiotherapy cannot be a part of managing these cancers. Radiotherapy is contraindicated by surgeons and oncologists for the treatment of OF. This is because it may further increase its risk of malignant transformation rate from almost 0.4 to 40 percent post-radiotherapy.
Conclusion:
Untreated and uncommon aggressive benign tumors or OF lesions can lead to various complications, both surgically and surgically, which can further deteriorate the patient's prognosis and survival rates. This is particularly evident in the case of rare OFs that exhibit intracranial spread or complications. When these tumors in the head and neck region begin to invade the skull base, numerous complications can arise, ranging from vision impairment to the spread of tumors to the meninges (protective layer of the nervous system), making surgical procedures even more complex and exacerbating the patient's prognosis. Therefore, the timely detection, diagnosis, and management of these tumors hold great significance.
