[Clinicopathologic study of thyroid carcinoma infiltrating the trachea]

A clinicopathologic study of 14 cases of thyroid carcinoma with tracheal infiltration and 70 control cases of thyroid carcinoma without tracheal infiltration was performed. The cases with tracheal infiltration were classified into well differentiated carcinoma in 5 cases, poorly differentiated carcinoma in 6, undifferentiated in 2, and squamous cell carcinoma in one, thus showing a higher frequency (54.5%) of poorly differentiated carcinoma than that (11.4%) in the control cases. A comparative study of biological behavior between well differentiated and poorly differentiated carcinomas revealed that the latter was more aggressive, and the lymphnode metastatic rate of which was higher. The prognosis of poorly differentiated carcinoma was poorer than that of well differentiated carcinoma. Selective en bloc resection of the tumor including the larynx and trachea was followed by the improved prognosis of advanced thyroid carcinoma with tracheal infiltration.