A large intraorbital arachnoid cyst with preserved visual acuity in a 3-year-old female: a case report and review of the literature

Arachnoid cysts (ACs) are the most common brain cysts, comprising 1% of intracranial lesions, with a higher prevalence in children (2.6%) than adults (0.3%-1.7%). Intraorbital ACs are extremely rare, with only a few cases reported to date, especially in children. While most ACs do not exhibit any symptoms, some cases of symptomatic ACs require surgical intervention to prevent brain damage. This article presents a unique case of a large intraorbital AC with preserved visual acuity in a 3-year-old female with a concise literature review of all intraorbital AC cases reported to date.

A 3-year-old Syrian female with a history of congenital ptosis presented with unilateral proptosis and eye pain in her left eye. She had normal visual acuity of 20/20 and a normal optic disc upon ophthalmic examination. Subsequent computed tomography (CT) and magnetic resonance imaging (MRI) identified a large Intraorbital AC, which was subsequently managed through surgical intervention, leading to complete improvement of proptosis. Follow-up imaging of the patient indicated no recurrence (refer to Graphical Abstract).

This article underscores the importance of considering surgery in cases of large symptomatic intraorbital ACs even if no signs of visual impairment are present, and highlights the need to recognize intraorbital AC as a rare but a potential cause of proptosis, while emphasizing the role of multimodal imaging in ruling out other possible differential diagnoses.