Gradenigo's Syndrome as First Presentation of Solitary Osseous Plasmacytoma of the Petrous Apex

Plasma cell tumors of the skull base are rare in neurosurgical practice. True solitary osseous plasmacytoma of the skull base without development of multiple myeloma is extremely rare. We report a case of typical Gradenigo’s syndrome, including left abducens nerve palsy, left facial pain and paresthesia in V1 and V2 distribution of trigeminal nerve caused by solitary osseous plasmacytoma of the left petrous apex. The patient was a 46-year-old man who presented with diplopia for two days. Magnetic resonance imaging (MRI) of the brain showed a hyperintense mass on T1-weighted images and slightly hypointense mass on T2-weighted images in the left petrous apex and left parasellar area. Through a left subtemporal middle fossa approach, subtotal resection of the lesion was performed. Histopathological examination of the lesion revealed plasmacytoma. The patient received 54 Gy radiation for the local tumor. Four months after radiation, the abducens palsy improved. Four years after treatment, the patient remained well with no symptoms or signs of local recurrence or progression to multiple myeloma.