Chronic hematic cyst of the orbit.

A chronic hematic cyst of the orbit caused unilateral globe displacement in four patients, two of whom had a past history of orbital trauma. The onset of a painless vertical displacement of the globe ranged from 3 weeks to 4 years. Computed tomographic (CT) findings demonstrated a homogeneous, nonenhancing, subperiosteal mass in the superior orbit in three patients and the inferior orbit in one. At surgery, all patients had masses surrounded by a pseudocapsule without epithelial or endothelial lining. The history, age distribution, and CT findings help to differentiate this entity from other causes of unilateral exophthalmos.