Lymphoid pseudotumour of the orbit.

A retrospective study of 55 patients with orbital lesions diagnosed on clinical grounds as cases of inflammatory pseudotumor was carried out to discover the relationship, if any, between the clinical and histological features and the response to treatment. It was found that few clinical parameters had a bearing on the subsequent progress of the lesion but B-scan ultrasonography was useful in identifying the lymphoproliferative mass. In 28 cases wherein histological material was available, the presence of follicles with germinal centres was found to indicate a good prognosis, whereas the presence of blast forms distributed randomly through the lymphoid tissue was associated with an inadequate response to corticosteroid therapy. Eosinophils were slightly more common in the corticosteroid-responsive lesions, but the presence of other leucocyte types was not helpful in determining prognosis.