What are the key types of nerve sheath tumors found in the intracranial region, and how can they be differentiated on imaging?

The primary nerve sheath tumors in the intracranial region are Schwannomas and Neurofibromas. Schwannomas typically present as well-circumscribed, enhancing masses often associated with cranial nerves, most commonly the vestibular nerve (acoustic neuroma). Neurofibromas are less common intracranially and may appear as fusiform enlargements of nerves, often associated with neurofibromatosis type 1. A key diagnostic feature is that Schwannomas are usually solitary, whereas neurofibromas can be multiple in neurofibromatosis. Common pitfalls include mistaking meningiomas or metastases for these tumors due to overlapping imaging characteristics.