Follicular Thyroid Carcinoma Metastases on Round Ligament of Liver.

We describe a case of a 69-year-old woman with follicular thyroid cancer of long evolution, with thyroidectomy 20 years before, who had remained clinically stable until now, when she started to present abnormal levels of serum thyroglobulin. An 123I whole-body scan showed a high uptake in the upper right half of her abdomen, and an 18F-FDG PET/CT located this focus at the liver's round ligament. Pathology findings after surgery showed the focus to be a differentiated thyroid cancer metastasis. This is an unusual presentation of differentiated thyroid cancer metastasis.