Orbital pseudotumour masquerading as Wegener’s granulomatosis

Abstract

A twenty-two year old female patient presented with new onset bilateral hard orbital masses and progressively worse tear lake problems. Computed tomography of the orbits revealed poorly differentiated bilateral orbital masses. Laboratory investigation revealed ANCA positivity. Routine biochemical investigations were all within normal limits. CXR was also normal. Biopsy of the orbital masses revealed non-specific histological findings. An initial diagnosis of Granulomatosis with Polyangitis (GPA) was postulated. Oral steroids were given followed by a rapid response to steroid therapy. The working diagnosis of GPA was abandoned and a diagnosis of idiopathic orbital inflammation (IOI), or orbital pseudotumour was made owing to the benign, non-infective, inflammatory pathology with no evident systemic or local cause. Tailoring off of steroids resulted in repeated flare ups, resulting in the initiation of methotrexate therapy. The patient is in remission and is currently on combined steroid and methotrexate treatment. IOI is a diagnosis of exclusion and a rapid response to steroids serves as a diagnostic aid but is not in itself diagnostic.