Author’s Disclosure Block: Evangelina Esposito, none; Christof Hänsli, none; Julie Vadboncoeur, none; Marie-Josée Aubin, none

Abstract Body
Purpose: To present an educational case series on neoplastic and infections presenting as masquerade syndromes. Study Design: Retrospective observational case series and associated literature review Methods: Patient charts were reviewed, and the literature was reviewed using the National Library of Medicine (PubMed) database. Results: Case 1 describes a 79-year-old woman with a history of multiple myeloma who presented with decreased vision, bilateral panuveitis, and unoneateral hypopion. A diagnostic vitrectomy was performed, yielding unremarkable cytology results. The causative agent was identified as CMV through PCR analysis of the intraocular fluid.Case 2 involves a 76-year-old woman with a history of hairy cell leukemia presented with suspected intraocular lymphoma of the right eye. Following a diagnostic vitrectomy, the analysis of the intraocular fluid using PCR confirmed a diagnosis of toxoplasmosis.Case 3 describes a 76-year-old man with a history of oat cell carcinoma presented with painless visual loss of the left eye. The ocular examination showed fibrinoid anterior uveitis with iris neovascularization. Extensive anamnesis and examination led to the diagnosis of masquerade syndrome due to metastatic disease. Conclusions: Three cases are presented here to illustrate tumoral and infectious diseases manifesting as masquerade syndromes. Applying high clinical suspicion and timely intervention facilitated accurate diagnosis and proposed management, thereby averting unnecessary procedures.