Giant cell astrocytoma of the retina in tuberous sclerosis.

The clinical and pathologic features of an unusual retinal glioma that was the only clinically overt manifestation of tuberous sclerosis in a 27-year-old woman are reported. The tumor was composed predominantly of large pleomorphic cells with glassy eosinophilic cytoplasm. Immunologic staining yielded positive results for gamma enolase, but not for glial fibrillary acid protein. The histologic and immunopathologic features of this tumor were essentially identical to the subependymal giant cell astrocytoma found in tuberous sclerosis. This case illustrates the large overlap in dysplastic astrocytic and neuronal differentiation that can occur in the retina of patients with tuberous sclerosis. Giant cell astrocytoma of the retina can be mistaken for a malignant tumor histologically by persons unfamiliar with this entity.