Case of the Week

Background:

• In the setting of trauma, extra-axial hyperdense findings may reflect hemorrhage, however differential considerations should include dural-based lesions.

Clinical Presentation:

• This patient presented to the emergency department  with only generalized headache following a ground level fall onto her head.

Key Diagnostic Features:

• The noncontrast CT head showed an extra-axial hyperdense lesion along the floor of the left middle cranial fossa. An MRI study demonstrated an enhancing, dural-based lesion that extended into foramen ovale concerning for perineural spread of malignancy. Gallium 68-DOTATATE imaging performed for further evaluation demonstrated intense radiotracer uptake within the mass and the foramen.

Differential Diagnosis:

• Extra-axial hyperdense lesions along the floor of the middle cranial fossa may represent traumatic subdural or epidural hemorrhage.
• Dural-based masses with perineural spread may be associated with mucosal or cutaneous squamous or basal cell carcinoma, salivary gland carcinoma (adenocystic carcinoma or mucoepidermoid tumor), metastasis, melanoma (usually desmoplastic), lymphoma, neurosarcoidosis, and sarcoma. Rarely, meningiomas can also exhibit perineural extension.
• Meningiomas, unlike most other intracranial neoplasms, express somatostatin type 2 receptors that concentrate Gallum-68 DOTATATE radiotracer, helping to confirm the diagnosis and extent of disease and to evaluate following tumor resection and radiation treatment.

Treatment:

• Although treatment typically involves surgical excision, when complete resection is challenging, external-beam radiation therapy may be considered for treatment of skull base meningiomas with perineural spread.