Calcified extra-axial cavernoma involving lower cranial nerves: Technical case report

OBJECTIVE: Extra-axial cavernomas involving cranial nerves (CNs) are uncommon vascular malformations and may cause neurological deficits. We report what is, to our knowledge, a unique case of a calcified extra-axial cerebellopontine angle (CPA) cavernoma involving the lower CNs. CLINICAL PRESENTATION: A 48-year-old man was admitted to our department with a 5-month history of gait instability and loss in tone of voice. A clinical examination documented gait disturbances and hoarseness but was otherwise unremarkable. Neuroradiological studies revealed a calcified mass in the lower third of the CPA cistern that was angiographically occult. It was associated with 3 additional lesions with a radiological appearance suggestive of multiple cavernomas. INTERVENTION: The patient underwent a retrosigmoid approach, and the calcified mass, tightly adherent to the lower CNs, was gently removed. The histopathological examination was consistent with a cavernoma. The postoperative course was characterized by a further lowering in the patient's tone of voice. At the 3-month follow-up examination, the patient showed significant improvement. CONCLUSION: CPA cavernomas are an extremely rare entity. Symptoms are generally related to CN compression, and subarachnoid hemorrhage is a very rare occurrence. The clinical and radiological appearance may mimic that of other CPA tumors (meningiomas, schwannomas). In spite of the benign nature and the very low risk of hemorrhage, we believe, with support from the literature, that surgical treatment is mandatory to prevent significant neurological deficits owing to the chronic CN compression.