A report of metachronous orbital involvement by IgG4 disease treated successfully with low-dose radiation therapy

Abstract

A 27-year-old woman with a history of hypothyroidism presented with a complaint of left eye pain and swelling that had progressed over the period of a year, in addition to a band-like frontal headache. A magnetic resonance imaging scan of the face and orbits was performed, demonstrating a 2.5 × 1.8 × 1.7-cm contrast-enhancing lesion within the intraconal space of the left orbit, inferolateral to and superomedially displacing the optic nerves with extension toward the orbital apex. The distal optic nerve appeared to be encased by the lesion. Representative axial and coronal images are shown in Fig 1A, B. At the time, the right eye did not appear to be involved radiographically or clinically. A biopsy of the left orbital mass demonstrated a chronic inflammatory infiltrate consisting of polyclonal mature B and T lymphocytes. She was treated empirically with a trial of steroids for several months without significant durable relief, including a period of hospitalization for high-dose intravenous steroids. Because of the progression of her orbital pain, opioid analgesics were ultimately required. She was subsequently treated with 3-dimensional conformal radiation therapy to the left orbit for the diagnosis of idiopathic orbital pseudotumor. A total dose of 2550 cGy was prescribed in 17 fractions and delivered with a mix of 6-