Euthyroid Graves' orbitopathy and incidental papillary thyroid microcarcinoma

Euthyroid Graves' orbitopathy (GO) combined with incidental papillary thyroid microcarcinoma has rarely been reported.

A 61-year-old Caucasian woman initially presented with progressive fatigue, exophthalmos, and thyroid function tests within normal limits. She underwent thyroidectomy, was found to have two incidental papillary thyroid microcarcinomas, and received radioactive iodine ablation to eliminate thyroid antigen. In addition to following her eye disease, TSH-receptor antibodies, thyroid stimulating immunoglobulins, and serum thyroglobulin measurements were recorded, demonstrating no evidence of thyroid cancer at four-year follow-up. At first, she had mild GO, developing into moderate-to-severe GO, and at 4 years she had Hertel measurements of 20 mm in both eyes.

This report underscores the difficulty of managing GO even when thyroid function is normal(ized) and thyroid antigen exposure has been minimized. In addition, it illustrates why antithyroidal antibodies should be considered in cases of concomitant papillary thyroid cancer, as thyroid cells can be stimulated not only by TSH but also by TSH-receptor stimulating antibodies.