A Simple Orbital Lymphatic Malformation Clinically Mimics Primary Conjunctival Cyst.

Introduction: A simple orbital lymphatic malformation usually presents with acute proptosis with ophthalmoplegia after an upper respiratory tract infection. Various treatments have been described but the lesions often recur after treatment due to their infiltrative nature.

Case presentations: A 6-year-old girl presented with a 5 × 10 mm translucent mass in the left inferior fornix for 3 years but she denied diplopia and visual disturbance. Orbital computed tomography with contrast emphasized the clinical findings, a nonseptated cystic lesion without enhancement in the anterior orbit. The lesion was surgically totally excised. Histopathological findings revealed an endothelial lining cyst without intraluminal cells consistent with a lymphatic malformation. In a 1-year follow-up, the lesion does not recur.

Conclusion: The simple orbital lymphatic malformation can present as a single nonseptate cystic lesion. Pathological study should be done for the definitive diagnosis. Surgical excision can achieve a favorable outcome.