Orbital inflammatory pseudotumor: clinicopathologic study of 22 cases.

Clinicopathologic features of orbital inflammatory pseudotumors were examined in 22 cases at the Kyushu University Hospital during the period from 1965 through 1981. These cases were divided into three groups according to the location of the tumors. Group I included 13 cases with the lesions located in the anterior portion of the orbit. The lesions of this group were often seen as a palpable mass without proptosis or visual disturbance. Histologically, most of them showed reactive lymphoid hyperplasia. In some lesions, fibrous tissue, in which eosinophils were scattered, was found around the lymph follicles. Group II consisted of 4 cases with the lesions situated in the anterior and posterior portion of the orbit. The patients of this group had severe proptosis without loss of vision. Histologically, reactive lymphoid hyperplasia was seen in all cases. Group III comprised 5 cases in which the tumor existed in the posterior portion of the orbit. The patients with these lesions had proptosis and visual disturbance. Histologically, the lesions of this group showed infiltration of various inflammatory cells including lymphocytes, plasma cells, mast cells and eosinophils. Most tumors in Group I were stationary for a long time without steroid therapy. Steroid therapy was effective to the patients of Group III. However, the lesion infiltrated progressively after steroid therapy in some patients of Group II.