Orbital pseudotumor: histopathological classification and treatment.

43 cases of orbital pseudotumor have been studied clinicopathologically during the past 20 years. Orbital pseudotumor might be histopathologically divided into three principal types: lymphoid, granulomatous and sclerosing types. Lymphoid and granulomatous types might be transformed into sclerosing type in the end stage, respectively. Lymphoid type showed good response to radiotherapy and poor or temporary response to steroid therapy. Granulomatous type indicated frequently good response to steroid and poor response to radiotherapy. Sclerosing type demonstrated poor response to steroid and radiation therapy. Therefore, orbital pseudotumor must be treated at an early stage.