Pediatric orbital pseudotumor: Case report and review of the literature

Inflammatory orbital pseudotumor represents an important diagnostic consideration in the approach to the patient with orbital disease. The diagnosis is applied to idiopathic orbital inflammation following exclusion of true neoplasm, primary infection, and other defined, often systemic inflammatory diseases [1]. Since the initial report by Birch-Hirschfield (as cited in Grossniklaus and coworkers [2]), there has been a rich literature describing the clinical manifestations, diagnosis, and treatment of this disorder. Pseudotumor must be distinguished from lymphoid neoplasms. In the past, these two disparate categories of orbital disease were lumped together, which obscured the natural histories of each and confounded the interpretation of therapeutic results, particularly with respect to radiotherapy (efficacious for lymphoid tumors) and corticosteroids (for pseudotumor). Inflammatory pseudotumor tends to be a more acute process, with distinctive topographical sites of involvement (Tenon's space, perioptic nerve connective tissues, lacrimal gland, extraocular muscles), and a hypocellular mixed inflammatory infiltrate with initial edema followed by progressive fibrosis. Lymphoid tumors, on the other hand, present more insidiously and usually are painless, tend to form unifocal masses in the orbit that mold to surrounding structures, and are hypercellular proliferations with a sparsity of collagen. Whereas pseudotumor can affect the orbital fat and form irregularly shaped and apparently infiltrative mass lesions as revealed by imaging studies (particularly subacute and chronic cases), because of pronounced fibrosis pseudotumors tend to be more symptomatic and cause more morbidity (motility restriction and optic nerve compression, for example) than comparably sized lymphoid tumors. Finally, although lymphoid tumors are probably the most common orbital neoplasms in adults, they are exceedingly rare in children. The bulk of the literature addresses orbital pseudotumor in adults. However, although inflammatory orbital pseudotumor is not common in the pediatric population, it is not rare. In the report of Blodi and Gass [3], 23 of 140 patients were younger than 20 years. The last major series of patients with pediatric orbital pseudotumor was presented by Jakobiec and coworkers [4, 5], but there are no recent, comprehensive reviews of the literature. To our knowledge, Grossniklaus and colleagues [2] describe the only reported case of inflammatory orbital pseudotumor in an infant. In this chapter, we present a case of a 7-month-old child with inflammatory orbital pseudotumor and review the literature regarding clinical characteristics, diagnosis, management, and prognosis. We then outline our approach to the child with orbital inflammation.