- Department of Neurological Surgery, UPMC Presbyterian Hospital, M8709 South Tower, 200 Lothrop Street, Pittsburgh, PA 15213, USA
- Department of Radiology, UPMC Presbyterian Hospital, M8709 South Tower, 200 Lothrop Street, Pittsburgh, PA 15213, USA
- Department of Neuropathology, UPMC Presbyterian Hospital, M8709 South Tower, 200 Lothrop Street, Pittsburgh, PA 15213, USA
Zachary J. Tempel
Department of Neuropathology, UPMC Presbyterian Hospital, M8709 South Tower, 200 Lothrop Street, Pittsburgh, PA 15213, USA
DOI:10.4103/2152-7806.114799Copyright: © 2013 Tempel Z J This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
How to cite this article: Tempel ZJ, Johnson SA, Richard PS, Friedlander RM, Rothfus WE, Hamilton RL. Parasellar arachnoid cyst presenting with a nonpupil sparing third nerve palsy mimicking a posterior communicating artery aneurysm in an adult. Surg Neurol Int 09-Jul-2013;4:87
How to cite this URL: Tempel ZJ, Johnson SA, Richard PS, Friedlander RM, Rothfus WE, Hamilton RL. Parasellar arachnoid cyst presenting with a nonpupil sparing third nerve palsy mimicking a posterior communicating artery aneurysm in an adult. Surg Neurol Int 09-Jul-2013;4:87. Available from: http://sni.wpengine.com/surgicalint_articles/parasellar-arachnoid-cyst-presenting-with-a-nonpupil-sparing-third-nerve-palsy-mimicking-a-posterior-communicating-artery-aneurysm-in-an-adult/
Background:Arachnoid cysts are congenital lesions that contain fluid identical to cerebrospinal fluid (CSF). They usually do not communicate with CSF spaces. The vast majority of arachnoid cysts are congenital asymptomatic lesions that are discovered incidentally. Those lesions that do become symptomatic typically present in childhood with signs and symptoms of intracranial hypertension, seizures, and focal neurologic deficits specific to cyst location.
Case Description:A rare case of a parasellar arachnoid cyst presenting with oculomotor palsy is presented. The patient is a 45-year-old male who presented with acute onset diplopia and frontal headache. Neurologic examination revealed right ptosis, pupillary dilation, and opthalmoparesis consistent with an oculomotor palsy. Computed tomography (CT) scan and lumbar puncture failed to reveal evidence of a subarachnoid hemorrhage. Magnetic resonance imaging (MRI) of the brain demonstrated a 1 cm right parasellar nonenhancing mass that was hyperintense on T2 flair and with a fluid-fluid level concerning for a thrombosed posterior communicating artery (PCommA) aneurysm. There was an additional finding of a left occipital pole intraparenchymal hemorrhage in the setting of multiple hereditary cavernomas. Formal cerebral angiography revealed normal intracranial and extracranial vasculature. The patient was taken to the operating room for a right frontotemporal craniotomy, which revealed compression of the right oculomotor nerve by an arachnoid cyst. The cyst was fenestrated and resected with decompression of the oculomotor nerve. Postoperatively, the third nerve palsy had completely resolved.
Conclusions:The above case demonstrates that arachnoid cysts should be considered in the differential for patients presenting with nonpupil sparing third nerve palsy and require timely surgical intervention. As is the case for an expanding PCommA aneurysm, prompt decompression results in the best chance for recovery of oculomotor nerve function.
Keywords: Arachnoid cyst, cavernoma, oculomotor palsy
Arachnoid cysts are well-described congenital fluid-filled structures lined with meningothelial cells first reported in the 16thcentury by Dutch Anatomist Pieter Paux and first described by Bright in 1831. [
Ashker et al. described a case similar to the one presented here, in which a 3-month-old boy presented with anisocoria, a sluggishly reactive right pupil and isolated unilateral internal opthalmoplegia. [
Additionally, there are reports of arachnoid cysts of the cavernous sinus presenting with third nerve palsies; [
The above described cases, while rare, still follow the general rule that arachnoid cysts, when symptomatic, most often present early in life. The case presented here is similar with respect to the constellation of symptoms; however, it differs in that this patient presented with acute onset of symptoms and presented as an adult, and the location of the cyst is different than any of the other reported cases.
The patient is a 45-year-old male with a past medical history significant for multiple hereditary cavernous hemangiomas and Hodgkin’s lymphoma in remission following treatment with chemotherapy and radiation. He presented to his primary care physician with acute onset double vision, frontal headaches, and lid lag of the right eye. On computed tomography (CT) imaging [
The patient was taken to the operating room and underwent a right frontotemporal craniotomy. Intraoperatively, a right parasellar cystic lesion resembling an arachnoid cyst was identified, medial to the third nerve, which was pushed laterally [
Formalin-fixed paraffin-embedded slides stained with hematoxylin and eosin. Sections showed a fragment of dense fibrous connective tissue attached to a long thin fibrous piece of tissue. There was no inflammation or other pathological changes. The thin fibrous material is likely leptomeningeal tissue, while the more fibrous fragment could be a portion of dura or fibrotic leptomeninges. (H and E, ×200)
Immediately following surgery, the third nerve deficit improved but was still present. At his routine 2-week postoperative visit, he had subjective complaints of intermittent diplopia without evidence of a third nerve palsy on neurologic examination. When he presented for his three-month postoperative visit, he was symptom free and neurologically intact. MRI at that time revealed no evidence of a residual or recurrent arachnoid cyst [
Arachnoid cysts are fluid-filled CSF-containing structures typically found incidentally on imaging. They are widely thought to be congenital abnormalities, and as such, they may be associated with hypoplasia of surrounding brain tissue and focal bony expansion of the skull overlying the cyst. There are reports of arachnoid cyst development as a consequence of trauma, infection, or hemorrhage; however, the pathologic components of these cysts are distinctly different from true congenital arachnoid cysts. Most arachnoid cysts are asymptomatic. The presentation of symptomatic cysts depends on the location and size of the cyst and usually occurs within the first two decades of life. Patients commonly present with signs/symptoms of elevated intracranial pressure (nausea/vomiting, headaches, visual disturbances), seizures, sudden deterioration due to hemorrhage or cyst rupture and focal neurologic deficits corresponding to cyst location. Rengachary and Watanabe [
On CT imaging, arachnoid cysts appear as extraparenchymal hypodense cystic masses approximating CSF with smooth, noncalcified walls. The cyst walls do not enhance with intravenous contrast. MRI typically reveals a cystic mass that is T2 hyperintense and typically without contrast enhancement. Arachnoid cysts generally do not exhibit restricted diffusion. Depending on the protein content of the cyst, the signal intensity on T1 imaging is variable.
The differential diagnosis of acute onset unilateral nonpupil sparing third nerve is fairly narrow and should immediately raise concern for a compressive lesion. The most common culprit is an expanding PCommA aneurysm; however, third verve tumors, uncal herniation, and mass lesions of the cavernous sinus can also produce a nonpupil sparing third nerve palsy. Approximately 90% of cases of aneurysmal third nerve palsy are due to a PCommA aneurysm; the remaining 10% of cases are due to aneurysms of the cavernous portion of the internal carotid artery or basilar tip, particularly superior cerebellar artery aneurysms. [
To date, there have been only a small number of reported cases of an arachnoid cyst presenting with unilateral nonpupil sparing third nerve palsy. The location of the arachnoid cysts in these cases is slightly more proximal to the case presented earlier and these cases occurred in children who were aged less than 18 months at the time of presentation. Further, these children presented gradually with variable components of oculomotor palsy and both cases resulted in residual oculomotor palsy following surgical intervention. The earlier case illustrates an unusual cause of a nonpupil sparing third nerve palsy caused by a parasellar arachnoid cyst in an adult whose symptoms resolved following surgical resection. The difference in outcome between the two previously reported cases and the case presented here is likely related to the timing of onset and subsequent operative intervention.
In this case, a coincident left occipital pole hemorrhage secondary to multiple hereditary cavernomas was noted. There was no indication for surgical intervention for an incidentally discovered asymptomatic cavernoma. While there are reports in the literature of coincident cavernomas and arachnoid cysts, there is no evidence to support a common underlying pathogenesis for the two distinct lesions. [
The above case demonstrates that arachnoid cysts should be considered in the differential for patients presenting with nonpupil sparing third nerve palsy and require timely surgical intervention. As is the case for an expanding PCommA aneurysm, prompt decompression results in the best chance for recovery of oculomotor nerve function.
1. Aiba T, Koike T, Takeda N, Tanaka R. Intracrianial cavernous malformations and skin angiomas associated with middle fossa arachnoid cyst: A report of three cases. Surg Neurol. 1995. 43: 31-4
2. Amagasa M, Sato H, Niizuma H, Suzuki J. Trigeminal neurinoma associated with suprasellar arachnoid cyst: Case report. Neurosurgery. 1986. 19: 454-7
3. Ashker L, Weinstein JM, Dias M, Kanev P, Nguyen D, Bonsall DJ. Arachnoid cyst causing third cranial nerve palsy manifesting as isolated internal ophthalmoplegia and iris cholinergic supersensitivity. J Neuroophalmol. 2008. 28: 192-7
4. Hustler A, Joy H, Hodgkins P. Isolated unilateral mydriasis with delayed oculomotor palsy secondary to intracranial arachnoid cyst. J AAPOS. 2009. 13: 308-9
5. Keane JR. Aneurysms and third nerve palsies. Ann Neurol. 1983. 14: 696-7
6. Raja IA. Aneurysm-induced third nerve palsy. J Neurosurg. 1972. 36: 548-51
7. Rengachary SS. Parasagittal arachnoid cyst: Case report. Neurosurgery. 1981. 9: 70-5
8. Rengachary SS, Watanabe I. Ultrastructure and pathogenesis of intracranial arachnoid cysts. J Neuropathol Exp Neurol. 1981. 40: 61-83
9. Tatli M, Guzel A, Keklikci U, Guzel E. Pediatric orbital multifocal cavernous hemangiomas associated with bilateral arachnoid cysts of the middle cranial fossa. J Neurosurg. 2005. 103: 454-7
10. Unalp A, Uran , N . Multiple cavernous malformations with supravermian arachnoid cyst. Indian J Pediatr. 2007. 74: 1034-6