Bilateral orbital pseudotumor in a patient with Takayasu arteritis: a case report and review of the literature.

Inflammatory orbital pseudotumor is often associated with rheumatologic disorders. It has been reported commonly with ANCA-associated vasculitides, especially granulomatosis with polyangiitis (Wegener's granulomatosis). There are also a few cases of large vessel vasculitis such as giant cell arteritis and Behcet's disease. Here, we report a patient with undiagnosed Takayasu arteritis presenting with proptosis and diplopia, with later diagnosis of an inflammatory pseudotumor of the orbit. In this case, we believe extensive involvement of blood vessels, including bilateral pulmonary artery stenosis, and elevated inflammatory markers that show disease activity may be related to pseudotumor formation in Takayasu arteritis. Since this is an unusual and unreported presentation of the disease, better estimation of a causal relationship may be possible in the future with further information. In conclusion, although uncommon, this case highlights that orbital pseudotumor may be an important finding in Takayasu arteritis. For early diagnosis, better treatment, and good prognosis, it should be considered in patients presenting with ocular symptoms similar to the other vasculitides.