Case of the Month

Edited by Robert N. Johnson, MD

Figures 1A and B: Color fundus montage of the right and left eye. Note the multiple pale, semi-translucent superficial retinal lesions in both eyes. The darker red spots are artifacts.

Figures 2A and B: Wide-angle fluorescein angiography of the right and left eye. Note the multiple areas of hyperfluorescence corresponding to the areas of pale, semi-translucent lesions in both eyes.

Figures 3A and B: SD-OCT of the right and left eye. The peripapillary lesion is more cellular and less cystic than the lesion below the inferotemporal arcade in the left eye (Figure B).

Figure 4: OCT-Angiogram of the lesion near the inferotemporal arcade in the left eye. Note the vascularity.

Figures 5A and B: Wide-field fundus autofluorescence of the right and left eye. Most of the lesions show very mild hypoautofluorescence. The nasal lesion in the left eye shows some hyperautofluorescence along its margin.

Case History

A 22-year-old man presented for evaluation of retinal lesions in both eyes.

On examination visual acuity was 20/20 in both eyes. His pupils were equal round and reactive with no afferent pupillary defect.  The intraocular pressure and anterior segment examination in both eyes were unremarkable. Fundus examination demonstrated multiple bilateral white translucent pale retinal lesions in both eyes, some of which appeared thickened cystic (Figure 1A and B). Fluorescein angiography (FA) showed significant hyperfluorescence of the lesions, as well as highlighted other more translucent retinal lesions (less visible ophthalmoscopically) as they become hyperfluorescent in the late phase (Figures 2A and B). Optical coherence tomography (OCT) showed these lesions to involve the inner retina, and the larger lesions showed cystic spaces (Figure 3). OCT-angiography showed significant vascularity within the cystic lesion below the inferotemporal arcade in the left eye (Figure 4). Fundus autofluorescence demonstrated that these lesions were mostly hypoautofluorescent (Figures 5A and B).

Differential Diagnosis

Retinoblastoma, Retinal astrocytoma, Capillary hemangioma, Retinitis pigmentosa

Additional History and Diagnosis

Upon further questioning patient had a history of tuberous sclerosis diagnosed clinically at the age of 15 months. There was no history of tuberous sclerosis in his family. He also had a history of cerebral astrocytic hamartomas (but no prior seizures), cutaneous facial angiofibromas, renal hamartomas, and subungual fibromas.

We recommended annual surveillance and genetic testing for future family planning.

Discussion

Tuberous sclerosis complex (TSC) is characterized by benign tumor formation in the central nervous system, eyes, skin, and in other organs. The first description was credited to Désiré-Magloire Bourneville in the 1880s. It is typically transmitted in autosomal dominant fashion with mutations in tumor growth suppressor genes TSC¹ and TSC.^1,2 De novo mutations may actually account for a majority of observed cases.³

In 1908 Heinrich Vogt named the triad of mental retardation, seizures, and facial angiofibromas, however these classic findings but are only seen in a minority of patients. The disorder is characterized by a set of diagnostic criteria which include ash leaf spots, facial angiofibromas, ungual fibromas, cortical tubers, giant cell astrocytoma, and retinal astrocytomas.⁴ Fluorescein angiography aids in highlighting the tumors as their vessels are permeable to fluorescein. OCT-angiography also demonstrates the extent of vascularity.

Intraocular tumors typically are white, globular, well-circumscribed elevated lesions which arise from the inner retina or optic nerve head. In younger children they tend to be translucent and may be mistaken for retinoblastoma.⁵ Later in life they may become increasingly nodular and calcific, with cystic spaces in the tumor. Retinal pigment epithelial depigmented patches have also been observed to be increased in patients with TSC, such as in our patient (Figure 5).^6,7

Typically, tumor growth is minimal and no treatment is indicated. Loss of vision may be attributed to tumor growth, vitreous hemorrhage, or intraretinal/subretinal exudation.⁴ On occasion, progressive enlargement and necrosis of the lesion may be mistaken for an amelanotic melanoma.⁸ At times the highly vascular component of the tumor may mimic a retinal angioma⁹ and necrosis of the astrocytoma may simulate a retinochoroiditis.¹⁰ Tumors involving the optic nerve may be elevated and calcific making them difficult to distinguish from optic nerve drusen.¹¹

 A wide range of presentations has been observed in cases of exudation varying from self-limiting to persistently progressive and vision threatening.¹² Laser photocoagulation,¹³ brachytherapy, transpupillary thermotherapy, endoresection,¹⁴ photodynamic therapy1⁵ have been utilized in the past. Rarely, progressive growth, tumor seeding, and neovascular glaucoma may necessitate enucleation.¹⁶ Systemic evaluation should be undertaken to identify other manifestations of the condition.

References

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