How to evaluate and manage an exostosis on the frontal bone of the skull?

From the Guidelines

Evaluation and management of a frontal bone exostosis should begin with a thorough clinical assessment including history and physical examination to determine if the lesion is symptomatic or cosmetically concerning, followed by CT scanning without IV contrast as the initial imaging study, as recommended by the American College of Radiology 1.

Clinical Assessment

The clinical assessment should include:

• History of the lesion, including duration and any changes over time
• Physical examination to determine the size, location, and tenderness of the lesion
• Evaluation of any symptoms, such as pain, functional issues, or cosmetic concerns

Imaging

Imaging is essential to characterize the lesion's extent and relationship to surrounding structures.

• CT scanning without IV contrast is the recommended initial imaging study for suspected frontal bone injury 1
• CT scanning can provide detailed information about the lesion's size, location, and relationship to surrounding structures
• MRI may be useful in certain cases, such as detecting a CSF leak from a skull base fracture or diagnosing the contents that have herniated through a defect in skull base injuries 1

Management

Most frontal bone exostoses are benign, slow-growing bony outgrowths that require no treatment if asymptomatic.

• For symptomatic cases causing pain, functional issues, or significant cosmetic concerns, surgical excision is the definitive treatment
• The procedure typically involves making an incision over the lesion, exposing the exostosis, and removing it with a bone rongeur or drill until the contour matches the surrounding bone
• Complete excision is important to prevent recurrence
• Postoperatively, patients may require pain management with acetaminophen or NSAIDs for 3-5 days
• Antibiotics are not routinely needed unless there are specific risk factors for infection
• Follow-up should occur at 1-2 weeks for wound check and then at 3-6 months to assess for recurrence
• Surgery is generally safe but carries risks of bleeding, infection, and rarely, damage to underlying structures
• The benign nature of these lesions means that pathological examination of the removed tissue is recommended to confirm diagnosis, though malignant transformation is extremely rare.

From the Research

Evaluation of Exostosis on Frontal Bone of the Skull

To evaluate an exostosis on the frontal bone of the skull, several factors should be considered:

• Clinical manifestations: High-frequency symptoms such as headaches, obesity, vertigo/dizziness symptoms, cognitive decline, and depression may be associated with hyperostosis frontalis interna (HFI), a condition characterized by abnormal bone growth on the posterior aspect of the frontal bone 2.
• Imaging features: Radiologic characteristics of hyperostosis cranialis interna (HCI) include significant thickening of the skull in the frontal, parietal, temporal, and occipital regions, mainly due to thickening of the inner table of the skull 3.
• Radiographic findings: Radiographic studies can help evaluate the size and location of frontal osteomas, which are usually benign in nature and commonly present with symptoms of facial deformity, facial pain, and headaches 4.

Management of Exostosis on Frontal Bone of the Skull

Management of exostosis on the frontal bone of the skull may involve:

• Surgical treatment: Superficial osteotomies with primary closure can be an effective method for removal of frontal bone periosteal osteomas with minimal side effects 4.
• Monitoring: Regular follow-up is necessary to monitor for recurrence or complications after surgical treatment.
• Consideration of associated symptoms: Clinicians should be aware of the possible association between exostosis and symptoms such as headaches, obesity, and cognitive decline, and consider these factors in the management plan 2.