Granulomatous necrotizing retinochoroiditis caused by Sporotrichum schenkii. Report of a case including immunofluorescence and electron microscopical studies

Abstract

A middle-aged man had blurred vision, redness, and pain in the right eye. Ophthalmoscopic examination revealed slowly progressive necrotizing retinitis in the peripheral superonasal quadrant. The clinical impression was toxoplasmic retinochoroiditis, but lesions failed to respond to steroids, pyrimethamine, and sulfonamides. The eye was enucleated and, histopathologically, showed necrotizing granulomatous retinochoroiditis and optic neuritis, numerous cigarshaped, yeast-like organisms located within the necrotic retina and subretinally, and a subretinal asteroid body. Organisms were identified as Sporotrichum schenkii by immunofluorescence techniques. Electron microscopical studies of the fungus disclosed an unusually thickened capsule with a well-developed cell wall, the outer portion of which exhibited a radiating pattern of granular filamentous material. The ability of S schenkii to cause endophthalmitis in a patient without apparent primary infection should be remembered in the differential diagnosis of a cryptogenic, slowly progressive intraocular infection.