Abstract
PURPOSE: To familiarize clinicians with the clinical and magnetic resonance imaging (MRI) features of a small orbital apex lymphaticovenous malformation that resulted in blindness and evaded timely clinical diagnosis. OBSERVATIONS: A 68-year-old man presented with severe vision loss due to a 9 mm mass at the apex of the orbit above the optic nerve. When surgically removed 4 years later, the lesion was characterized by vascular spaces of varying size. Larger ones were filled with fibrin and organized thrombi. Stromal septa of endothelial-lined cavernous spaces were partially necrotic and there was evidence of remote hemorrhage. Some endothelial cells expressed D2-40, a marker of lymphatic channels. CONCLUSIONS AND IMPORTANCE: Unless a high index of suspicion is maintained for a lymphaticovenous malformation the clinical diagnosis of a small but vision-threatening lesion can be overlooked.