Background: Aicardi syndrome is a cerebroretinal disorder originally described in 1965. Its salient clinical features are infantile spasms, agenesis of corpus callosum, hypsarrhythmia, and a pathognomonic optic disc appearance consisting of multiple depigmented chorioretinal lacunae clustered around the disc.
Methods: Clinical report with cranial computed tomography and biopsy results.
Results: A 3-year-old female patient presented with Aicardi syndrome and progressive proptosis of the left eye since birth. Visual acuity was light perception only in the right eye. Ocular motility examination showed large angle of left exotropia. Direct funduscopy showed a large optic nerve head and chorioretinal lacunae in the right eye; the left eye was not visible. Magnetic resonance imaging detected a large retrobulbar cyst and left microphthalmia. The patient underwent neurosurgery. Intraoperative microscopic dissection of the dural membrane led to exposure of an underlying cyst, which was 80% resected. Biopsies of walls of the orbital cyst showed fragments of neuroglial and meningothelial tissues with some calcification and mild chronic inflammation. Psammoma bodies were identified. The diagnosis was heterotopic brain tissue.
Conclusions: Heterotopia of brain tissue within the orbits is a very rare finding. Two previous reports have described an orbital cyst in association with Aicardi syndrome, both attributed to encephaloceles. We report a very rare case of heterotopia of brain tissue in Aicardi syndrome. The patient did not have an encephalocele.