Extraorbital Inflammatory Pseudotumor of the Head and Neck: CT and MR Findings in Three Patients

Case 2.

A, Coronal unenhanced T1-weighted image through the base of the skull. The left pterygopalatine fossa appears infiltrated by soft tissue (thick arrow), isointense with muscle, extending into the inferior orbital fissure (thin arrow). On the opposite side, the pterygopalatine fossa displays its normal high T1 signal intensity, with the internal maxillary artery (arrowhead) visible as a signal void.

B and C, Sagittal contrast-enhanced T1-weighted images through the left pterygopalatine fossa: C is 4 mm medial to B. The enhancing mass lesion (arrows, B) is seen to grow through the inferior orbital fissure (white arrow, C) in the orbital apex and into the superior orbital fissure (black arrow, C).