Intraconal Sarcoidosis
Findings:
Axial T2 and T1 fat suppressed post contrast images demonstrate decreased T2 signal within the left intraconal fat, with diffuse patchy enhancement after gadolinium administration and no expansile characteristics.
Discussion:
The orbits and eyes are involved in 20 to 25% of sarcoidosis patients, typically as a uveitis. 7 to 20% of sarcoidosis patients present with ocular symptoms. In isolated orbital disease, involvement of the lacrimal glands most common and is almost always unilateral. The differential diagnosis for this process include sarcoidosis, lymphoma, metastasis, and orbital pseudotumor. On imaging, the marked T2 hyperintensity is a helpful distinguishing feature, but not absolute since lymphoma may also show decreased T2 signal. Extralacrimal orbital disease may appear infiltrative or as a focal mass.