Abstract: Objective To discuss the clinical characteristics of patients with primary squamous cell carcinoma of the thyroid(PSCCT) and secondary squamous cell carcinoma of the thyroid(SSCCT). Methods The medical records of 17 PSCCT patients and 6 SSCCT patients admitted to Peking Union Medical College Hospital were systematically reviewed.Clinical symptoms, ultrasound, and pathological characteristics were compared between the two groups. Results The percentage of the female was higher than male and the mean age of diagnosis was about 56 years old in each group. The most common chief complaint of the patients was neck mass in both groups. The percentage of patients with cough(P＜0.01) was higher in SSCCT group than PSCCT group. The mean size of the tumor in PSCCT group was larger than SSCCT group(P＜0.05). Papillary thyroid carcinoma (PTC) could be complicated with or recurrent as PSCCT. The mean survival time after diagnosis was 17.1 months in the PSCCT patients and 13.5 months in the SSCCT patients. Predictors of overall survival (OS) in PSCCT patients included age, enlarged cervical lymph node, radical operation, and PTC. Conclusions SCCT is aggressive with neck mass as the most common chief complaint. PTC could be combined with or recurrent as PSCCT. Age, enlarged cervical lymph node, radical operation, and PTC were the predictors of OS in PSCCT patients.

Key words: thyroid, squamous cell carcinoma, cancer, head and neck, papillary thyroid carcinoma