Orbital metastasis as primary manifestation of thyroid carcinoma.

A 59-year-old woman with unknown primary tumor developed progressive painless left upper eyelid swelling and exophthalmos. Computed tomography (CT) showed a well-circumscribed left orbital mass producing bone lysis. Immunohistologic staining of the incisional biopsy specimen was positive for thyroglobulin, suggesting an orbital metastasis from thyroid carcinoma. At this time, thyroglobulin was high (1400 ng/dL). Total thyroidectomy with lymph node dissection disclosed a follicular carcinoma with microscopic foci of papillary variant follicular carcinoma. Two months after radioiodine treatment, the CT showed a regression of the orbital tumor mass with concomitant decrease in thyroglobulin (428 ng/dL). Although orbital metastases of thyroid carcinoma are uncommon, thyroid carcinoma has to be considered as a potential primary tumor in a patient with an orbital metastasis.