Primary squamous cell carcinoma of the thyroid gland: a case report and review.

BACKGROUND Primary squamous cell carcinoma (SCC) of the thyroid gland is a rare malignancy that presents with advanced disease and poor prognosis. METHODS A 75-year-old woman with a history of Hashimoto thyroiditis presented with 6 months of dysphagia and stridor. Imaging revealed a thyroid mass invading the larynx. Primary SCC of the thyroid was diagnosed by histopathologic and immunohistochemical evaluation. Total thyroidectomy, total laryngectomy, bilateral modified neck dissection, and adjuvant radiotherapy (RT) were performed. Radiologic follow-up at 21 months demonstrated no disease and total length of survival was 31 months. RESULTS Despite an aggressive T4aN0M0 tumor, survival in this case was more than double the median survival rate previously reported. Concomitant Hashimoto thyroiditis is rare and histopathologic and immunohistochemical evaluation is imperative for an accurate diagnosis. CONCLUSION The case and literature reported here support that a thorough diagnostic workup of primary SCC of the thyroid with aggressive locoregional surgery and adjuvant RT may improve the length of survival.