Recurrent Planum Sphenoidale Meningioma Presenting as Nasal Mass

Case Report A 55-year-old man presented to the rhinology clinic for evaluation of unilateral nasal obstruction. He had 7 months of progressive right-sided nasal obstruction, as well as feeling that his right ear was plugged for the previous 2 months. He had no other symptoms including vision changes, numbness, epistaxis, or pain. On physical exam, he was found to have a firm, flesh-colored mass medial to the turbinates that occupied the majority of the nasal cavity. It extended into the nasopharynx and was blocking the eustachian tube opening, as he also had a right middle ear serous effusion.

His medical history was remarkable for a large planum sphenoidale meningioma that extended to the cribriform plate. He underwent subtotal resection via bifrontal craniotomy 16 years prior, which was followed by a course of external beam radiation. He had a recurrence at the right orbit and underwent Gamma Knife radiosurgery 11 years after his initial diagnosis. He was also on lifelong anticoagulation therapy with warfarin due to factor V Leiden deficiency.

During his yearly MRI surveillance, he was noted to have a right nasal cavity mass since 2011 that was elected to be observed. The mass was isointense on T2-weighted sequence, and homogenously enhancing on postcontrast images. The mass slowly but progressively grew over the observation period, with subsequent development of right sphenoid and right maxillary sinus opacification. On CT imaging, there was hyperostosis of the cribriform plate, nasal septum, and superior and middle turbinates.

The patient was taken to the OR for endoscopic endonasal biopsy and resection after he was bridged off of warfarin. Frozen section pathology confirmed the diagnosis of meningioma (WHO Grade I). The nasal mass very firm and fibrous, but the majority was debulked using the microdebrider. The mass originated from the skull base at the cribriform plate and extended onto the nasal septum and middle turbinate. The mucosa of the turbinate and septum were removed, and the underlying bone was drilled and then cauterized with bipolar. There was no evidence of cerebrospinal fluid leak at any point during the procedure. The patient had an unremarkable recovery period.

Discussion Although unusual, meningiomas along the anterior skull base can extend extracranially into the sinonasal cavity and present with nasal obstruction or mass. This patient’s nasal mass presented 8 years after his initial diagnosis and was thought to represent sinonasal polyps. However, on retrospective review of his imaging, there was an area of suspected continuity between the residual intracranial meningioma and nasal mass. The imaging characteristics were also more typical for meningioma than nasal polyp, with T2 isointensity and homogenous contrast enhancement with gadolinium. Once the diagnosis is confirmed, these masses are often amenable to resection through an endoscopic endonasal approach. Recurrent extracranial meningioma should remain on the differential diagnosis for nasal mass in patients with a history of skull base meningioma, even many years after initial diagnosis and treatment.