Abstract
Follicular carcinoma is only occasionally diagnosed preoperatively, because of the difficulty to discriminate it from benign adenoma using fine needle aspiration cytology and imaging studies. When follicular carcinoma is diagnosed as “follicular neoplasm” preoperatively, thyroid lobectomy has commonly been selected in Japan. Follicular carcinoma without distant metastasis has a good prognosis, but with distant metastasis it will be life-threatening. It is clinically meaningful to analyse some factors of distant metastasis. In this report, we analysed various factors in patients and their pathological findings. As a result, a post-operation decrease of serum thyroglobulin had significant predictive factors of distant metastasis in follicular carcinoma. Before metastases appeared, serum thyroglobulin increased before clinically detected in this report, so periodic monitoring of serum thyroglobulin is very important. Bone scintigraphy and FDG-PET imaging will be important to find distant metastasis earlier. When distant metastases are found in such examinations, completion thyroidectomy and radioactive iodine therapies will be needed to improve their prognoses.
