Diagnosis of Idiopathic Inflammatory Pseudotumor of the Orbit

ABSTRACT

For an accurate diagnosis we analyzed 15 cases of clinically suspected idiopathic inflammatory pseudotumor(pseudotumor). The patients were 11 men and 4 women(mean age, 45.9 years). They were followed up for an average of 22 months. The final diagnosis was drawn collectively with clinical symptoms and signs, orbital computed tomography(CT), pathologic finding, and response to corticosteroids. In most instances the pathologic reading was reactive lymphoid hyperplasia(RLH). The final diagnosis was not constantly correlated with the pathologic reading; 5 were pseudotumor,6 RLH, and 4 undetermined. It could be concluded that the pseudotumor in the case which presented acute in flammatory symptoms and sings, involved the entire orbit in CT scan, or was cured by corticosteroid therapy. In the cases of no significant inflammatory sings it was difficult to differentiate pseudotumor from RLH with CT scan, pathologic finding, or response to corticosteroids. Although CT-guided fine needle biopsy often provides an insufficient specimen for pathologic diagnosis, it seems a useful diagnostic method, which is a simple and noninvasive technoque. At least the other orbital tumors or granulomatous lesions could be excluded by CT-guided fine needle biopsy.