Unique case of trigeminal neuralgia due to Epstein-Barr-virus-associated B-cell lymphomatoid granulomatosis of the Meckel's cave and cavernous sinus: Important clinical and therapeutic implications

BACKGROUND: Trigeminal neuralgia (TN) represents one of the most disabling pain syndromes. Several diseases have been described as etiological triggers of TN, vascular compression of the trigeminal nerve being the most frequent cause. Here, we describe for the first time a rare case of TN caused by an infiltration of an isolated Epstein–Barr virus (EBV) B-cell lymphomatoid granulomatosis (LYG) mass into the Meckel's cave and cavernous sinus. CASE DESCRIPTION: A 51-year-old woman undergoing immunosuppressant treatment for Crohn's disease presented due to right-sided TN. Magnetic resonance imaging (MRI) scans revealed an isolated lesion affecting the right Meckel's cave and lateral wall of the cavernous sinus. We accomplished tumor resection through a subtemporal extradural approach and the patient recovered successfully from surgery. Histological examination revealed an LYG, and a blood test confirmed low but positive EBV counts. The immunosuppressant therapy was discontinued and we assumed a watchful waiting management. During a 41-months’ follow-up there was neither evidence of LYG recurrence nor an increase of EBV counts. CONCLUSIONS: LYG, an angiodestructive disease associated with EBV reactivation in the context of immune dysfunction and often associated with an aggressive behavior or even malignant transformation, should be considered as a rare differential diagnosis of TN associated with skull base lesions. The management of this rare disease is still controversial and varies from limiting the treatment to correcting immune dysfunction up to chemotherapy. In this case of an isolated mass, surgical excision and discontinuation of immunosuppressants were effective to prevent the relapse of the disease in a long-term follow-up.