Clinical study of squamous cell carcinoma of the thyroid gland

Squamous cell carcinoma of the thyroid gland is a rare disease. Although several mechanisms have been proposed, the pathogenesis of the disease is not known. A majority of cases are at an advanced stage at the time of diagnosis and the clinical course is extremely aggressive. This is because the tumor often invades directly into neighboring organs, metastasizes, and is refractory to conventional treatments. As a result, a clinically effective therapy is not established for this biologically aggressive tumor with extremely poor prognosis. From January 2000 to December 2012, there were three cases of squamous cell carcinoma of the thyroid gland, accounting for 1.1％ of all thyroid cancers treated in our department. Two patients who were treated with radical surgery plus chemoradiotherapy developed distant metastases. One of them died at 20 months after the initial treatment, while the other remained alive with metastatic tumor for 44 months. One inoperable patient died 5 months after CRT. For operable cases, multimodality treatment with radical surgery may be preferable, leading to longer survival.