Liver Metastasis from Thyroid Carcinoma 32 Years After Resection of the Primary Tumor: Report of a Case

Follicular thyroid carcinoma is a differentiated cancer originating from the follicular cells in the thyroid gland. A 73-year-old woman, who had undergone curative resection of thyroid carcinoma 32 years earlier, was referred to our hospital after ultrasonography showed a solid mass in the liver. Laboratory data revealed positive hepatitis B core antibody, but all other values were normal. Computed tomography showed a round tumor, about 1.5cm in diameter, which was enhanced early and washed out later, in segment 5 of the liver. She underwent laparotomy and partial resection of the liver. Microscopic examination showed follicular cells with minimal atypia growing in a thyroid follicular pattern with colloids, whereby a diagnosis of metastatic liver cancer from thyroid follicular carcinoma was made. This is a rare case of solitary liver metastasis appearing 32 years after eradication of primary follicular carcinoma. Although the reason for the delayed presentation of the metastatic lesion remains unclear, this case shows that patients with differentiated thyroid cancer should be followed up for their entire life.