Orbital Metastasis of Undifferentiated/Anaplastic Thyroid Carcinoma.

A 52-year-old woman presented with decreased vision, diplopia, esotropia, proptosis, and right orbital pain. Clinical examination was suspicious for an orbital mass and additionally revealed a thyroid gland mass. Imaging studies showed an enhancing mass within the right lateral rectus muscle and a heterogeneous mass in the left lobe of the thyroid gland. Excisional biopsies of the thyroid and orbital lesions were consistent with metastatic undifferentiated/anaplastic thyroid carcinoma. This represents the first reported case of undifferentiated/anaplastic thyroid carcinoma metastatic to the orbit.