Orbital metastasis as primary clinical manifestation of thyroid carcinoma--case report and literature review.

Capillary thyroid carcinoma (PTC) is the most common neoplasm of thyroid. It usually grows slowly and is clinically indolent; although rare, its aggressive forms with local invasion or distant metastases can occur. Metastatic thyroid carcinoma rarely involves the orbit. We reported an uncommon case of orbital metastasis of PTC. A 66-years-old woman presented proptosis of the right eye. The biopsy of the tumor in orbit revealed metastatic thyroid carcinoma. The ultrasensitive TSH level was 1,34 mUI/L and free T4 level was 1,65 ng/dL. A total thyroidectomy was performed and histopathological analysis of the nodule revealed follicular variant of papillary thyroid carcinoma. Currently, the patient has been receiving palliative chemotherapy with Clodronate Disodium. The importance of the case is due to its unusual presentation, which emerged as a primary clinical manifestation. Although rare, thyroid carcinoma should be suspected in orbit metastasis.