From the Guidelines
An ossifying fibroma of the frontal sinus is a rare, benign, slow-growing tumor that develops in the frontal sinus cavity of the skull, characterized by the replacement of normal bone with fibrous tissue containing varying amounts of mineralized material, and its diagnosis and treatment should prioritize complete surgical excision to prevent recurrence and potential complications.
Key Characteristics
- Ossifying fibromas belong to a group of fibro-osseous lesions and typically affect people between 20-40 years of age, with a female predominance 1.
- Patients may present with symptoms such as frontal headaches, facial asymmetry, nasal obstruction, or visual disturbances if the tumor grows large enough to compress surrounding structures.
- Diagnosis involves imaging studies like CT scans, which typically show a well-demarcated, expansile lesion with a mixed density pattern, and histopathological examination of tissue samples.
Diagnostic Approaches
- CT scans are superior to MRI in the depiction of osseous anatomy and can detect skull base foraminal widening, which may alert to perineural tumor spread 1.
- MRI is considered superior to CT in the delineation of the soft tissue extent of disease, including involvement of neighboring structures.
Treatment
- The standard treatment is complete surgical excision, usually through approaches like endoscopic sinus surgery or open craniotomy depending on the size and location.
- Complete removal is important to prevent recurrence, which can happen in approximately 10-20% of cases.
- While these tumors are benign, they can cause significant problems due to their expansile growth pattern and location near critical structures like the orbit and brain.
Considerations
- The use of contrast-enhanced imaging is imperative to correctly identify and outline the primary tumor, distinguishing it from the surrounding normal soft tissues 1.
- The precise determination of bony destruction or remodeling may prove useful in the characterization of slow-growing versus aggressive sinonasal tumors.
From the Research
Definition and Characteristics
- Ossifying fibroma is a rare, benign fibro-osseous tumor composed of bone, fibrous tissue, and cementum 2.
- It is commonly found in the mandible, but can also occur in the maxilla and paranasal sinuses, including the frontal sinus.
Location and Symptoms
- Ossifying fibroma can occur in various locations, including the ethmoid sinus 3 and the frontal sinus, although the latter is not specifically mentioned in the provided studies.
- Symptoms may include pain, orbital/ocular symptoms, sinonasal symptoms, neurologic symptoms, and other symptoms, depending on the location and size of the tumor 4.
Treatment and Management
- Treatment of ossifying fibroma typically involves surgical excision, with the approach depending on the location and size of the tumor 2, 4, 5.
- Endoscopic surgery is a common approach for treating fibro-osseous lesions, including ossifying fibroma, in the paranasal sinuses 4, 5, 3.
- A complete en bloc excision is often required to relieve symptoms and prevent recurrence, especially when the tumor is located in the maxilla and paranasal sinuses 2.
Specific Considerations for Frontal Sinus Ossifying Fibroma
- While there is no direct evidence in the provided studies specifically addressing ossifying fibroma of the frontal sinus, the information on ossifying fibroma in general and its treatment in other paranasal sinuses can be applied to this location.
- The treatment approach for frontal sinus ossifying fibroma would likely involve endoscopic surgery, similar to other paranasal sinuses 4, 5.