CASE STUDY

Insidious Skull Base Meningioma Coincident With Central Serous Chorioretinopathy

A cranial tumor presents as CSC.

CHUN-JU LIN, MD • WEN-LU CHEN, MD • JANE-MING LIN, MD • YI-YU TSAI, MD, PhD

Central serous chorioretinopathy is a common disorder characterized by accumulation of serous fluid under the neurosensory retina, secondary to a localized defect of the outer blood-retinal barrier. It is most common in male patients 20 to 55 years old with the so-called type A personality.

In older patients, CSC usually presents as retinal pigmentary disease with leakage on fluorescein angiography of undetermined source.¹ Choroidal vascular hyperpermeability, manifested by areas of hyperfluorescence, is observed in the midphase of indocyanine green angiography.

Meningioma is a disease with considerable morbidity, and it is more commonly diagnosed in women than men. Suprasellar meningiomas are generally benign, well circumscribed, slow growing, and asymptomatic, and they often remain undiagnosed.² Among these lesions, skull base meningiomas are challenging tumors owing to their close proximity to important intracranial neurovascular structures.

Here, we report the case of an older man with insidious skull base meningioma initially presenting as CSC. The atypical course of CSC alerted the clinician to the need for further neuroimaging studies.

CASE REPORT

A 61-year-old man with moderate body weight recently complained of visual disturbances in the left eye. His best-corrected visual acuity was 20/20 in the right eye and 20/40 in the left eye. Neither relative afferent pupillary defect nor pallor of the optic nerve was found in either eye. Grade 1 cataract was noted. Funduscopy showed retinal pigmentary changes in both eyes. The disc showed a clear margin and was pinkish in color with no elevation in both eyes.

Fluorescein angiography revealed multifocal pinpoint leakage and mild peripapillary leakage (Figure 1). Optical coherence tomography was insignificant in the right eye but demonstrated focal anatomical alterations of the junction between photoreceptor tips and the retinal pigment epithelium without serous retinal detachment in the left eye (Figure 2). CSC in old age was diagnosed.

Figure 1. Fluorescein angiography (left) revealed multifocal pinpoint leakage and mild peripapillary leakage in the right eye. In the left eye (right), multifocal pinpoint leakage and mild peripapillary leakage were seen.

Figure 2. Optical coherence tomography (left) was insignificant OD. Focal anatomical alterations of the junction between photoreceptor tips and retinal pigment epithelium without serous retinal detachment were demonstrated OS (right).

However, the patient’s vision worsened in the left eye during two months of follow-up. No painful sensation on globe movement was noted. His BCVA decreased to counting fingers, but the retinal lesion remained unchanged. No obvious proptosis, disc swelling, headache, or other neurological signs were found.

Visual field examination showed a near full field OD, but a severely compromised field was noted OS (Figure 3, next page). Compressive optic neuropathy was suspected. Brain MRI revealed a left skull base meningioma 4.7 x 4.2 cm in size (Figure 4, left).

Figure 3. A) Visual field showed near full-field OD. B) Severely depressed field was noted OS.

Figure 4. A large homogenous enhancing, extra-axial meningioma in the left suprasellar and parasellar region, with dural tail sign, causing encasement and focal narrowing of the left terminal internal carotid artery, proximal anterior cerebral artery and middle cerebral artery. Follow-up MRI (right) showed that residual meningioma was controlled by subsequent Gamma Knife radiosurgery.

Left craniotomy was performed, and one medial sphenoid ridge meningioma approximately 5 cm in size, which encased the left internal cerebral artery and severely compressed the left optic nerve with optic canal invasion, was removed grossly. Small dense tumor tissue over the internal carotid artery/middle cerebral artery perforators was left due to severe adhesion.

Pathology showed meningothelial meningioma (WHO grade I). Microscopically, the tissue showed meningotheliomatous-type meningioma composed of plump meningotheial cells with abundant eosinophilic cytoplasm arranged in fascicles or whorls. Immunohistochemical study showed positivity for epithelial membrane antigen. S-100 protein and glial fibrillary acidic protein assays were negative.

The residual meningioma was controlled by Gamma Knife radiosurgery (Figure 4, right). The patient’s BCVA improved to 16/20 postoperatively. No recurrence was noted over one year of follow-up.

DISCUSSION

In a series from the Blue Mountains Eye Study, the causes of unilateral blindness and visual impairment in the older population included age-related macular degeneration, other retinal diseases, cataract, glaucoma, corneal and neurological disease.^3,4 Neurological disease was less frequent, and the incidence was only 6%.⁴

In this elderly patient with unilateral visual impairment, grade 1 cataract could not fully explain the visual impairment. Neither relative afferent pupillary defect nor disc pallor was found in either eye, so retinal disease was pursued first. FA revealed multifocal pinpoint leakage. OCT demonstrated focal anatomical alterations of the junction between photoreceptor tips and the RPE in the left eye.

Therefore, CSC in old age was diagnosed initially. However, the patient’s vision deteriorated over two months of follow-up, although the retinal lesion remained unchanged. Neurological diseases were strongly suspected then, and a skull base meningioma was confirmed by brain MRI and surgical pathology.

Meningiomas are most common in people between the ages of 40 and 70 years old. They are more common in women than in men. Some research has suggested a link between meningiomas and hormones (estrogen plus progesterone).

Hormonally related risk factors have long been hypothesized to be associated with meningioma risk in women.⁵ However, the relationship between the current use of exogenous hormones and meningioma remains unclear.⁶

Endogenous estrogen-associated factors, such as high body mass index, can increase meningioma risk in both sexes.^6,7 Our male patient was of moderate weight without a hormone-related exposure history, so suspicion of meningioma was not aroused at the presentation.

Meningiomas account for approximately 1% of sellar masses and are more vascularized and invasive than pituitary adenomas.² The most common symptoms are visual disturbances (58%), headache (16%), and incidental findings (12%).

After surgery, visual disturbances improve in most patients (80%).^1,8 The vision of our patient also improved dramatically after skull base tumor removal and subsequent Gamma Knife radiosurgery.

Apart from CSC, suprasellar meningiomas masquerading as atypical retrobulbar optic neuritis have also been reported.⁹ Retrobulbar optic neuritis, which presents with normal appearance of the optic disc, is found in 65% of cases. Unlike our patient, who experienced painless gradual visual loss, optic neuritis is characterized by unilateral sudden loss of vision in the affected eye and often accompanied by periocular pain.

Skull base meningiomas are challenging tumors owing to their close proximity to important neurovascular structures. Complete microsurgical resection can be associated with significant morbidity, and recurrence is also a concern.¹⁰

Gamma Knife radiosurgery can be an adjunct to microsurgery for patients whose comorbidities substantially increase the risks with complete resection. Stereotactic Gamma Knife surgery offers a high rate of tumor control and neurological preservation in patients.¹⁰

The visual disturbances of skull base meningioma can insidiously present as CSC in elderly male patients. Skull base meningioma provokes an exercise in the differential diagnosis of unilateral visual impairment. Coincidental retinal diseases might distract from the correct diagnosis of intracranial lesions initially. Physicians should be aware of the possible comorbidities.

Our patient’s atypical course of CSC alerted the clinician to the necessity for neuroimaging studies. Microsurgery adjunctive to Gamma Knife radiosurgery offered sound tumor control and neurological preservation in this patient with skull base meningioma. In cases of vision deterioration despite a stable retinal lesion, further imaging modalities are mandatory. RP

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