Submacular Neovascular Membrane and Focal Granulomatous Inflammation

Background: Subretinal choroidal neovascular membranes in persons younger than 55 years old are commonly idiopathic or associated with the ocular histoplasmosis syndrome. There have been a few reports describing the histopathologic features of these membranes. Studies have shown that idiopathic membranes have the same morphologic features as membranes in age-related macular degeneration except for the absence of basal laminar deposits. Method: The authors studied a clinicopathologic case of a macular lesion associated with two peripheral hypopigmented spots in a healthy 30-year-old woman. Results: The clinical and fluorescein angiographic findings in this patient were characteristic of a submacular neovascular membrane, except that the edge of the lesion remained distinct in the late phase of the fluorescein angiogram. Results of histopathologic examination of the surgically excised membrane showed a well-circumscribed granuloma containing some eosinophils. Attenuated vascular spaces were present within the hard tubercle. Special stains for micro-organisms were negative. The patient had no evidence of a systemic inflammatory disease. Conclusions: A visible edge despite intense staining in the late phases of a fluorescein angiogram may suggest the possibility of subretinal granulomatous inflammation in a lesion that otherwise appears like a neovascular membrane. The clinical distinction between this pattern of subretinal neovascularization and a typical idiopathic membrane may be important because subretinal granulomatous inflammation could respond to treatment with systemic corticosteroids.