Parasellar Meningioma

This patient is a 58 year old woman from Peru who, in 1975, developed intermittent headaches and right retro-orbital eye pain. She was seen by several ophthalmologists in South America who were unable to make a diagnosis. In March 1977 she awoke one morning with vertical diplopia most marked on looking up. The diplopia persisted unchanged. She had no impairment of vision, ptosis or proptosis. In June 1977 she was hospitalized in Lima, Peru, under the care of a neurologist. At that time, she had partial ptosis of the right eye (OD). He suspected a diagnosis of ocular myasthenia gravis. She received no medication. In June 1978 ocular myasthenia was again considered. This time, by an ophthalmologist who documented an esotropia and intermittent hypertropia OD. In November 1978 the patient's brother, a physician in the US, referred her for further evaluation and she was seen in the Neurology Clinic at the Massachusetts General Hospital (MGH) and admitted. Neuro-Ophthalmological examination: Sense of smell intact Visual acuity 20/20 OU with normal color vision Visual fields and fundoscopic examination normal. Pupils equal, brisk to light and near Partial ptosis OD Palpebral fissure OD 7 mm, OS 10 mm. Range of levator function 12 mm OU No myasthenic lid twitch or increased ptosis on fatigue. No exophthalmos, eyes measured 16 OU base 96 with normal orbital resilience. Normal corneal reflex No ocular pulsation or bruit Ocular motility OD: Partial ptosis Paresis of the superior rectus and Inferior oblique (double elevator) Inferior rectus, medial rectus normal Superior oblique (cranial nerve 4) normal Lateral rectus (cranial nerve 6) normal Absent Bell's No signs of aberrant reinnvervation of the 3rd nerve Diagnosis: Compressive lesion of the third nerve (trunk) sparing the pupil. Differential Diagnosis: 1.Pituitary adenoma 2.Aneurysm of the intracavernous portion of the internal carotid artery (ICA) 3.Parasellar meningioma 4.Atypical craniopharyngioma 5.Chordoma CT scan showed a contrast enhancing mass with a horizontal diameter of 3 cm. in the right parasellar area in the middle fossa. The mass extended superiorly to obscure part of the chiasmatic cistern. The supraoptic portion of the third ventricle did not appear to be compromised. (Figures 1 and 2) X-rays of the skull, orbits and optic foramen showed no erosive changes and only a question of possible hyperostosis of the bone close to the anterior clinoid process. The superior orbital fissures were normal. Bilateral carotid angiogram by retrograde femoral artery catheter showed changes consistent with a meningioma, encasing the right supraclinoid ICA. (Figures 3) There was also displacement of the supraclinoid segment of the ICA medially and upward due to mass effect. The ophthalmic artery on the right side filled well and was visualized just beneath the level of the encased right ICA. (Figures 4 and 5) There was a vascular ‘blush' staining the mass.(Figures 6 and 7) Diagnosis: 1.Right parasellar meningioma 2.Partial third nerve (trunk) palsy sparing the pupil 3.Partial cavernous sinus syndrome 4.Encasement of the supraclinoid ICA. Neurosurgical Consultation: Conservative management without a biopsy was recommended. Treatment: She received radiation therapy, 5,050 Rads in 37 elapsed days treating 26 fractions during that time. Two portals were treated daily, a right superior oblique and a right lateral field to optimize dose distribution to the right parasellar region. She was treated using 10 MV X-rays with cerrobend cutouts. These were 6 cm. in diameter. Treatment was weighted one-to-one. The patient tolerated the treatment well and she was discharged. Follow-Up: Plans were made for her follow-up in Lima, Peru and every two years at the MGH. She returned in Oct 2002. The neuro-ophthalmological examination, which hitherto had been perfectly stable, showed new signs of aberrant reinnervation of the third nerve with increasing ptosis on abduction and elevation of the eyelid on adduction. Primary aberrant reinnervation (PAR) of the third nerve is a well recognized sign of chronic nerve compression by a cavernous sinus or parasellar meningioma or other mass lesion such as an ICA aneurysm within the sinus. PAR has also been reported with compression of the third nerve by a basilar artery aneurysm. Brain MRI 2002 showed a homogenous contrast enhancing extra axial mass arising from the right posterior clinoid sphenoid bone measuring 2.1 x 2.1 x 2.0 cm. (AP/SI/LR). (Figure 8) There was partial encasement of the right ICA at the siphon with slight narrowing of the vessel at this level. The mass abutted the right cavernous sinus and showed dark to iso-intense signal abnormalities on both the T1 and T2 images and relatively uniform enhancement consistent with a diagnosis of a meningioma. (Figure 9) There was superior displacement of the right optic chiasm and optic nerve and displacement of the medial aspect of the right temporal lobe laterally. A small dural tail extended along the right temporal pole. The mass showed no evidence of entry into the sella turcica and there was no deviation of the pituitary stalk. The sella appeared partially empty. MRA/Head showed mild narrowing of the right ICA siphon. The Circle of Willis was otherwise normal. See also: http://content.lib.utah.edu/cdm/ref/collection/ehsl-shw/id/259