Radiology study of orbital pseudotumor

The objective of our study is to present the most characteristics CT and MR findings associated with the typical forms of onset of OPT, myositis, diffuse form, dacryoadenitis, periscleritis and perineuritis, pointing out the most useful findings for the differential diagnosis. We have reviewed 19 cases of OPT diagnosed in our hospital between 1987 and 1993. The ages of the patients ranged from 32 to 80 years; pediatric patients were excluded from the study. The most frequent clinical presentation was unilateral exophthalmos and the most common radiological sign was the increase in size of one or more of the extrinsic ocular muscles. Orbitral pseudotumor is an uncommon lesion that is defined as a nonspecific inflammatory reaction of unknown cause or occurring in the absence of underlying systemic disease. The diagnosis is based on the exclusion of other diseases and on the good response to corticosteroid therapy. CT is the technique of choice to assess its extension and the structures involved. (Author) 5 refs