W(h)ither orbital pseudotumor?

Orbital pseudotumor is a nonspecific, idiopathic benign inflammatory process characterized by a polymorphous lymphoid infiltrate with varying degrees of fibrosis. We retrospectively reviewed the clinical presentation, management, and progress of six consecutive patients referred to our service with an initial diagnosis of orbital pseudotumor to underscore the challenge and pitfalls in managing this group of patients. Three male and three female patients, aged 27 to 74 years, presented with a variety of ophthalmologic problems, including orbital swelling, chemosis, proptosis, blepharoptosis, restricted eye motion, diplopia, and visual loss. The initial diagnosis of orbital pseudotumor was based on clinical findings, results of routine laboratory screening tests, computed tomographic and/or magnetic resonance imaging scans, and the response to corticosteroid treatment in three patients. In these three patients, the final diagnosis of orbital pseudotumor was confidently made only in one patient who remained in remission after corticosteroid therapy. The remaining two patients had Miller-Fisher syndrome and thyroid ophthalmopathy. Three other patients initially diagnosed with orbital pseudotumor underwent biopsy through an orbitotomy with comprehensive histopathologic evaluation. Two of these patients were subsequently diagnosed with non-Hodgkin lymphoma. Orbital pseudotumor belongs to a spectrum of lymphocytic infiltrative orbital conditions. It is a diagnosis of exclusion. The initial diagnosis must be regarded as provisional, and failure of complete resolution with corticosteroid therapy should heighten the index of suspicion and a biopsy should be considered. However, diagnosis may be difficult even with comprehensive histopathologic studies.