Clinicopathological studies of minimal thyroid and ordinary thyroid cancers

Clinicopathological studies were carried out on 27 patients with minimal thyroid cancer and 56 with ordinary thyroid cancer at Kanazawa University, from April, 1979 to December, 1982. There was a significant difference in the rate of preoperative diagnosis between the minimal and the ordinary cancer groups. Subtotal thyroidectomy with modified neck dissection was usually performed in both groups. The histological types in minimal cancer group included 16 papillary carcinomas, 7 nonencapsulated sclerosing carcinomas, one follicular carcinoma, one anaplastic carcinoma with squamous cell metaplasia and two multiple mixed carcinomas. There was no significant difference in the rates of intrathyroidal and lymph node metastases between the two groups. While the metastatic lesions of sclerosing carcinoma were localized to the central cervical lymph nodes, the ordinary cancer in general and the papillary variant of minimal cancer metastasized not only to the central cervical lymph nodes but also to the ipsilateral and even to the contralateral jugular lymph nodes.