Submacular neovascular membrane and focal granulomatous inflammation

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.

The authors studied a clinicopathologic case of a macular lesion associated with two peripheral hypopigmented spots in a healthy 30-year-old woman.

The clinical and fluorescein angiographic findings in this patient were characteristic of submacular neovascular membranes, 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.

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.