Cystic trochlear nerve neurinoma

Area of Science:

• Neurosurgery
• Neuropathology
• Neuroimaging

Background:

• Neurinomas, benign nerve sheath tumors, can occur along cranial nerves.
• The trochlear nerve (CN IV) is rarely affected by cystic neurinomas.
• Accurate diagnosis is crucial for appropriate management.

Observation:

• A cystic neurinoma of the trochlear nerve presented as a brainstem lesion.
• The patient's history and clinical presentation were consistent with a brainstem mass.
• Preoperative imaging findings were initially interpreted as an intrinsic brainstem lesion.

Findings:

• Histopathological examination confirmed a cystic neurinoma of the trochlear nerve.
• The tumor's cystic nature and location mimicked intrinsic brainstem pathology.
• Surgical intervention was performed for definitive treatment.

Implications:

• This case highlights the importance of considering extrinsic lesions, such as neurinomas, in the differential diagnosis of brainstem masses.
• Accurate preoperative diagnosis can be challenging but is essential for surgical planning.
• Successful surgical management of trochlear nerve neurinomas is feasible.