Invasive orbital pseudotumor--CT demonstration of extension beyond orbit.

Two cases of orbital pseudotumor are described with computed tomographic (CT) studies showing extension of the pseudotumor beyond the confines of the bony orbit. In one patient with orbital pseudotumor involving the medial rectus muscle, the pseudotumor extended through the medial wall of the orbit into the ethmoid sinus. A second patient had extension of orbital pseudotumor into the infraorbital fissure causing enlargement of the infraorbital fissure and foramen. Both lesions were confirmed by biopsy.