Abstract
We report, herein, a case of immunoglobulin (Ig)G4-related disease affecting the orbital foramen and paranasal sinuses. A 54-year-old man was diagnosed as having chronic sinusitis and underwent four rounds sessions? of endoscopic sinus surgery at a local otolaryngological clinic. Lack of improvement in the nasal symptoms and onset of left ocular proptosis following this treatment led to a diagnosis of recurrent chronic sinusitis and orbital cellulitis, and the patient was referred to our hospital. Contrast-enhanced computed tomography of the paranasal sinuses revealed dense soft tissues in the ethmoid sinuses on both sides, osseous defects in the orbital lamina papyracea, dense soft tissue in the region of the medial rectus muscle, and enlargement of the lacrimal gland and infraorbital groove ..side..?. Immunoglobulin analysis of the peripheral blood showed elevated serum IgG (3062 mg/dl) and IgG4 (1060 mg/dl) levels. IgG4-related disease was suspected, and endoscopic sinus surgery was conducted using a navigation system to obtain a definitive diagnosis. Histopathological examination of specimens of the affected paranasal sinus mucosa and orbital tissue obtained intraoperatively revealed extensive infiltration by IgG4-positive plasma cells, confirming the diagnosis of IgG4-related disease. Postoperative systemic steroid therapy was administered at the Department of Rheumatology, which resulted in marked improvement of the nasal symptoms and left ocular proptosis. The patient remained well at least until the 12-month follow-up postoperatively. In patients with periorbital swelling accompanied by paranasal sinus lesions, IgG4-related disease should be considered in the differential diagnosis, in addition to conditions such as malignant lymphoma and sinusitis with orbital complications.
