Thyroid carcinoma with biphasic clinical course and evolution in medullary carcinoma-follicular variant. A case report and an immunocytochemical demonstration of calcitonin and thyroglobulin in the same neoplastic cells.

The authors present an unusual case of thyroid neoplasia firstly diagnosed as an anaplastic carcinoma with no rise in plasma thyroglobulin (Tg) and treated with total thyroidectomy and radioiodine administration. After 18 months regional lymph node metastases were present with a rise in plasma calcitonin (Ct) (8000-14000 pg/ml); lymphectomy and external… (More)