Endocrine Abstracts

Thyroid eye disease (TED) represents the most frequent and important extrathyroidal manifestation of Graves' disease. Less commonly the eye changes may occur in euthyroid individuals without a preceding history of thyrotoxicosis, represents approximately 8-21% of TED cases. Patients with the rare combination of primary hypothyroidism and TED are predisposed to severe eye disease and atypical presentation of such patients may delay diagnosis and treatment . The primary importance of unilateral eye involvement particularly in euthyroid individuals is the need for rapid exclusion of the rarer etiologies of unilateral proptosis, many of which are neoplastic in nature. Conditions that may be confused with TED include pseudotumor of the orbit, infiltrative leukemia of the orbit, fibrous dysplasia of bone, retrobulbar hemangiomas, ophthalmic vein thrombosis, cavernous sinus thrombosis, meningiomas, retrobulbar hemorrage, histiocytosis and any other involvement of the orbit by malignancy. The combination of unilateral thyroid eye disese (TED) and primary hypothyroidism is extremely rare. We presented a 38 years old man having primary hypothyroidism and TED. The mechanism by which hypothyroidism or TSH elevation accelerates ophthalmopathy has not been elucidated. Some possible mechanisms may be speculated such as; presentation of shared thyroid eye antigen by thyrocytes, direct effect of TSH on circulating lymphocytes, enhanced GAG synthesis by fibroblasts.