Resistant thyrotoxicosis: A case of sarcoidosis of thyroid

Abstract

Autoimmune endocrinopathies and, less commonly, thyroid autoimmune disease have been reported in patients with sarcoidosis. Similarities exist in the pathogenesis of these two conditions. Concomitant sarcoidosis in the thyroid gland in patients with Graves’ disease may contribute to the resistance to antithyroid drugs and radioiodine therapy. We present the clinical, laboratory, imaging, and pathologic findings of a patient with Graves’ disease who was unresponsive to medical management. This 37-year-old man presented with thyrotoxicosis. Thyroid hormone assays and 99mTechnitium findings were consistent with Graves’ disease. He was also found to have hilar lymphadenopathy. Patient failed to achieve remission with high doses of antithyroid drugs and 2 sessions of radioiodine ablative therapy. Histopathology of lymph nodesdisclosed noncaseating granulomas, consistent with sarcoidosis. Patient's thyrotoxicosis subsided only following steroid administration. The histopathology of the thyroid gland on aspiration and the subsidence of symptoms with steroids reiterate the possibility of thyroid sarcoidosis. This diagnosis needs biopsy for confirmation, which our patient didn't consent for.