Distant Metastases from Thyroid Carcinomas
From 1928 to 1965, 383 cases of thyroid carcinoma were studied at the National Cancer Institute of Milan; among these cases 113 had distant metastases. The metastases were more frequent in patients aged fro 60 to 69. The female/male ratio was about 2:1. The lesions were more often in the skeleton (74 cases) and in the lungs (64 cases). Since a high incidence of skeletal metastases without lung involvement has been observed, the authors postulate that metastatic spread from thyroid carcinoma may occur also through vertebral veins. In undifferentiated carcinomas distant metastases occur quite early (87 % at 5 years). On the contrary, in differentiated carcinomas, metastases occur later: after 5 years from thyroidectomy in 31 per cent of patients with follicular carcinomas metastases were found and in 74 per cent after 10 years. In papillary carcinomas the percentage is 17 and 52 after 5 and 10 years respectively. Among 113 cases with distant metastases, 50 showed the first metastatic localization to the regional lymph nodes; this occurrence was found to be more frequent in papillary and unidifferentiated carcinomas (χ2 = 11.805).