Oman Journal of Ophthalmology

CASE REPORT
Year
: 2019  |  Volume : 12  |  Issue : 2  |  Page : 125--128

Choroidal schwannoma presenting with neovascular glaucoma: A report of two cases


Sai Divya Jajapuram1, Dilip K Mishra2, Swathi Kaliki1,  
1 The Operation Eyesight Universal Institute for Eye Cancer, Hyderabad, Telangana, India
2 Ophthalmic Pathology Laboratory, L V Prasad Eye Institute, Hyderabad, Telangana, India

Correspondence Address:
Dr. Swathi Kaliki
The Operation Eyesight Universal Institute for Eye Cancer, L V Prasad Eye Institute, Hyderabad - 500 034, Telangana
India

Abstract

Schwannoma is a rare benign tumor, which is more commonly found elsewhere in the body along myelin-producing peripheral nerves and is rarely reported within the eye. In this report, we describe two adult patients presenting with a choroidal mass lesion and neovascular glaucoma who underwent enucleation with clinical differential diagnoses of choroidal melanoma and choroidal hemangioma. Histopathology confirmed the diagnosis of choroidal schwannoma. This case series highlights the variable presentation of intraocular schwannoma and how they masquerade as other choroidal tumors.



How to cite this article:
Jajapuram SD, Mishra DK, Kaliki S. Choroidal schwannoma presenting with neovascular glaucoma: A report of two cases.Oman J Ophthalmol 2019;12:125-128


How to cite this URL:
Jajapuram SD, Mishra DK, Kaliki S. Choroidal schwannoma presenting with neovascular glaucoma: A report of two cases. Oman J Ophthalmol [serial online] 2019 [cited 2020 Dec 4 ];12:125-128
Available from: https://www.ojoonline.org/text.asp?2019/12/2/125/259685


Full Text



 Introduction



Choroidal schwannoma frequently misleads the clinician to a more ominous diagnosis of amelanotic melanoma owing to its clinical resemblance and sometimes may be misdiagnosed with choroidal hemangioma or leiomyoma. Schwannomas are benign encapsulated tumors, more common in orbit than intraocular when presented in ophthalmic practice and contribute to 1% of all orbital tumors.[1] Intraocular schwannoma is relatively rare with around 50 cases published worldwide. Callender and Thigpen first described intraocular schwannoma in 1930. Intraocularly, they presumably arise from the nerve sheaths of ciliary nerves and are reported more commonly in the choroid and ciliary body than iris.[1],[2] Herein, we report a case series of two patients diagnosed with choroidal schwannoma based on histopathology.

 Case Reports



Case 1

A 56-year-old male presented with a history of diminution of vision in the right eye for 10 years and a recent onset of pain and congestion for 3 months. He was on anti-glaucoma medications for raised intraocular pressure (IOP) in the right eye. He denied perception of light in the right eye and had a vision of 20/25 in the left eye. On examination, the conjunctiva of the right eye was congested with an intercalary staphyloma extending from 1 to 3'o clock [Figure 1]. The IOP was 36 mm Hg in the right eye and 14 mm Hg in the left eye. Anterior and posterior segment examination of the left eye was unremarkable. Anterior segment examination of the right eye revealed diffuse corneal stromal edema, diffuse neovascularization of the iris, subtotal hyphema, relative afferent pupillary defect, and posterior subcapsular cataract. A hazy cornea with dense posterior capsular opacity precluded fundus examination. B-Scan ultrasonography revealed a 4.5 mm × 4.5 mm × 6 mm mass with moderate-to-high surface echogenicity and internal echoes with surrounding retinal detachment. Differential diagnoses of the right eye choroidal hemangioma and malignant melanoma were considered. Due to inconclusive diagnoses and presentation with a painful blind eye, the patient underwent enucleation of the right eye.{Figure 1}

On gross examination, a grayish-white nodule with circumscribed margins was noted in the choroid with surrounding detached retina. An area of scleral thinning was noted from 1 to 3'o clock. Microscopically, a circumscribed nodule with spindle cells loosely packed in short fascicles with collagenous stroma was noted. The cells had vesicular nuclei with small nucleoli and mild anisonucleosis. There was no evidence of necrosis or mitotic figures. Immunohistochemistry (IHC) with S-100 was strongly positive while being negative for HMB-45 and Melan-A. MIB-1 index was <1%. Based on the histopathology features and IHC, a diagnosis of choroidal schwannoma was confirmed.

Case 2

A 33-year-old female presented with a history of diminution of vision for 2 years. On examination, the visual acuity in the right eye was counting fingers at 2 m, and 20/20 in the left eye. The anterior segment examination of both eyes was unremarkable. Posterior segment examination of the left eye was normal. On dilated fundus examination of the right eye, an amelanotic choroidal tumor measuring 8.5 mm × 9 mm was noted adjacent to the optic disc in the macular region with surrounding subretinal hard exudates and hemorrhages. Ultrasonography revealed a dome-shaped lesion with moderate internal reflectivity. Based on the clinical findings, a clinical diagnosis of choroidal hemangioma was made. The poor visual potential in the right eye was explained to the patient and treatment options of observation versus plaque radiotherapy were discussed. In view of poor visual prognosis with treatment and benign nature of the tumor, the patient did not want any intervention and thus opted for observation. The patient presented 2 years later with a rise in intraocular pressure and neovascular glaucoma. A differential diagnosis of amelanotic melanoma was then considered and enucleation of the right eye was performed.

On gross examination [Figure 2], a grayish white nonpigmented mushroom shaped mass measuring 10 mm × 6 mm was noted in the peripapillary region. Microscopically, a cellular circumscribed lesion with variable cellularity was seen in the posterior pole over the optic nerve head. Cellular areas comprised spindle cells in bundles and fascicles with oval to elongated nuclei. Focal areas of nuclear palisading (Antoni A) with verrocay bodies alternating with few hypocellular areas (Antoni B) with foamy cells and blood vessels were seen. IHC with S-100 was strongly positive, Glial fibrillary acid protein (GFAP) showed poor uptake, and melan-A and HMB-45 were negative. Based on these findings, a final diagnosis of choroidal schwannoma was made.{Figure 2}

 Discussion



Intraocular schwannomas are benign tumors arising from Schwann cells and may be misdiagnosed as choroidal hemangioma[2] or and amelanotic choroidal melanoma. Choroidal hemangiomas are orangish-red and ultrasonography reveals an acoustically dense dome-shaped lesion with high surface reflectivity and moderate-to-high internal reflectivity. Fundus fluorescein angiography reveals hyperfluorescence and indocyanine green angiography reveals early hyperfluorescence and late washout phenomenon. Amelanotic choroidal melanoma appears as a yellowish lesion and ultrasonography reveal a dome-shaped or mushroom-shaped lesion with acoustic hollowness at the base. Scan ultrasonography shows high surface reflectivity and medium-to-low internal reflectivity. Fundus fluorescein angiography reveals hyperfluorescence with dual circulation and indocyanine green angiography reveals hyperfluorescence and delayed staining. Intraocular schwannomas can present as an isolated lesion or can be associated with neurofibromatosis in 8.5% of the cases.[2] They are commonly found in adult females with an average of 37 years of age (range 6 months–76 years).[2],[3] Fundus examination reveals an amelanotic yellowish-white lesion with associated subretinal fluid with/without subretinal exudation, and thus can simulate amelanotic choroidal melanoma. Ultrasonography may not be useful in accurately distinguishing choroidal schwannoma from melanoma due to similar features of high surface reflectivity with low-to-moderate internal echoes in both. Fluorescein angiography can simulate a choroidal hemangioma with initial filling in the choroidal and arterial phases and increased staining with bright hyperflourescence in the late stages. However, indocyanine green angiography of choroidal schwannoma differs from hemangioma with the absence of late wash-out phenomenon. A definitive clinical diagnosis of choroidal schwannoma was not done in both the cases in our series and most of the eyes reported till date were enucleated in view of diagnostic dilemma. A transscleral biopsy may be useful in confirming the diagnosis. However, in our cases, enucleation was done in both cases owing to the late presentation with painful blind eye and neovascular glaucoma. Presentation of choroidal schwannoma with neovascular glaucoma is rare and has not been reported in the literature.

Pathologically, schwannomas have spindle cells with bland nuclei arranged in alternating Antoni A (hypercellular areas with nuclear palisading) and Antoni B (less widely dispersed hypocellular areas in myxoid matrix) patterns with hyalinized vasculature as noted in our patients. Immunohistochemical markers can differentiate schwannomas from melanoma with S-100 being strongly positive, GFAP showing poor uptake in schwannomas while melanocytic markers such as melan-A and HMB-45 are negative in schwannomas except in pigmented variants.[4],[5]

The management options for intraocular schwannomas include transscleral resection and photodynamic therapy.[6],[7] Schwannomas can be observed without any intervention owing to their benign nature and slow growth. Treatment with anti-vascular endothelial growth factor may be useful to treat the surrounding exudation secondary to the high vascular nature of intraocular schwannomas.[8] However, a definitive diagnosis of choroidal schwannoma by clinical examination is rare and is most often diagnosed on the enucleated eye as in our case series.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1Kim IT, Chang SD. Ciliary body schwannoma. Acta Ophthalmol Scand 1999;77:462-6.
2You JY, Finger PT, Iacob C, McCormick SA, Milman T. Intraocular schwannoma. Surv Ophthalmol 2013;58:77-85.
3Chen JJ, Kamberos NL, O'Dorisio MS, Syed NA, Boldt C. Choroidal schwannoma in a 6-month-old girl. J AAPOS 2014;18:197-9.
4Shields JA, Font RL, Eagle RC Jr., Shields CL, Gass JD. Melanotic schwannoma of the choroid. Immunohistochemistry and electron microscopic observations. Ophthalmology 1994;101:843-9.
5Lee SH, Hong JS, Choi JH, Chung WS. Choroidal schwannoma. Acta Ophthalmol Scand 2005;83:754-6.
6Cho YJ, Won JB, Byeon SH, Yang WI, Koh HJ, Kwon OW, et al. A choroidal schwannoma confirmed by surgical excision. Korean J Ophthalmol 2009;23:49-52.
7Damato B, Damato EM, Konstantinidis L, Heimann H, Coupland SE. Choroidal schwannoma: A case series of five patients. Br J Ophthalmol 2014;98:1096-100.
8Wong HK, Lahdenranta J, Kamoun WS, Chan AW, McClatchey AI, Plotkin SR, et al. Anti-vascular endothelial growth factor therapies as a novel therapeutic approach to treating neurofibromatosis-related tumors. Cancer Res 2010;70:3483-93.