Sporadic Retinal Astrocytic Hamartoma Mimicking Retinoblastoma in a Child: A Case Report and Literature Review

Abstract

Retinal astrocytichamartoma (RAH) is a rare benign glial neoplasm most commonly associated with tuberous sclerosis complex (TSC). Sporadic cases, occurring in the absence of systemic phakomatosis, are uncommon and may closely mimic retinoblastoma, particularly when presenting with a calcified intraocular mass, creating a diagnostic challenge with potentially irreversible therapeutic consequences. We report a 6-year-old boy with progressive exotropia and complete visual loss in the right eye. Multimodal imaging revealed a calcified posterior intraocular mass with diffusion restriction and contrast enhancement on MRI, features highly suspicious for retinoblastoma. Given the high radiologic suspicion of malignancy, the absence of residual visual potential, and the unavailability of optical coherence tomography, primary enucleation of the right eye with orbital implant placement was performed. Histopathological and immunohistochemical evaluation demonstrated astrocytic proliferation with focal glialfibrillary acidic protein (GFAP) positivity and synaptophysin negativity, favoring RAH; however, the unavailability of cone-rod homeobox (CRX) and other neuronal markers precluded definitive exclusion of well-differentiated retinoblastoma. The postoperative course was uneventful, and at one-year follow-up the patient remained clinically stable with no recurrence or intracranial pathology on MRI. This case illustrates the difficulty of differentiating sporadic RAH from retinoblastoma in young children when advanced diagnostics are limited, and underscores the need to weigh over treatment of a benign lesion against the risk of an unrecognizedintraocular malignancy. Expanding access to OCT and comprehensive immunohistochemistry is essential to reduce diagnostic uncertainty and unnecessary enucleation.