Idiopathic sclerosing inflammation of the orbit. A distinct clinicopathologic entity

Idiopathic sclerosing inflammation of the orbit is a poorly delineated, fibrosing, immune-mediated entity resulting in significant ocular disability. To characterize this process and propose more specific and effective therapy, clinical and pathologic findings in 16 cases are reviewed.

The clinical records of 16 patients with biopsy-proven disease were retrospectively reviewed to determine demographic and clinical features, radiologic features, course, management, and outcome. These findings were correlated with pathologic features to describe this unique entity. Immunohistologic characteristics were compared with those of a clinically and histopathologically similar process, retroperitoneal fibrosis.

The study included 11 male and 5 female patients, ranging in age from 8 to 81 years. Disease onset was usually unilateral (14/16) and chronic (11/15), with two distinct anatomic presentations, lacrimal (11/16) and apical (3/16), characterized by infiltration (15/16), mass effect (12/16), and visual loss (3/16). The most common signs and symptoms were dull pain (13/16), proptosis (11/16), mild inflammation (11/16), restricted motility (9/16), swelling (9/16), and diplopia (8/16). Two features, a sparse, chronic inflammatory infiltrate, the immunopathologic characteristics of which suggested a cell-mediated process, and a desmoplastic stroma of early onset, dominated the pathologic picture. Treatment with corticosteroids (11/16), radiotherapy for steroid failures (8/11), and observation alone (3/16) was inadequate, resulting in blindness in 3/16 cases, restricted movement in 10/16, and complete resolution in only 2/16 patients.

Idiopathic sclerosing inflammation of the orbit is a unique clinicopathologic entity, similar to retroperitoneal fibrosis, that is characterized by primary, chronic, and immunologically mediated fibrosis, poor response to corticosteroid treatment or radiotherapy, and frequent visual disability. Early and aggressive immunosuppressive therapy is recommended.