1987 Volume 26 Issue 1 Pages 151-156
Cytologic and histopathologic findings of a primary squamous cell carcinoma arising in the thyroid gland are reported together with the histogenesis. The patient, a 38-year-old male, complained of hoarseness and dyspnea of three weeks' duration. The thyroid, 10 × 5 cm in size, was diffusely enlarged. Laryngoscopy revealed a papillomatous nodule in the right false vocal cord. Total thyroidectomy and laryngectomy were performed, based on the diagnosis of double cancers in the thyroid and larynx.
In touch smears made from fresh tissues of the thyroid tumor, large polygonal cells with atypia were observed, revealing a sheet-like pattern and tendency for keratinization. In addition, a number of rather small and undifferentiated tumor cells were found. Macroscopically, the tumor, measuring 6×5×3 cm, was located in the isthmus of the thyroid and invaded into the both lobes, surrounding soft part and tracheal wall, resulting in tracheal stenosis and mucosal ulceration. The tumor also showed extensive submucosal lymphogenous spread from the trachea to the larynx, and metastasized to the right false vocal cord as a papillomatous tumor, 0.5 cm in diameter. Apart from these lesions, a thyroglossal duct cyst including a squamous component was present near the hyoid bone. Histologically, the tumor corresponded to moderately differentiated squamous cell carcinoma, keratinizing type, and was composed of tumor cells with predominantly clear cytoplasm. Histogenetically, the thyroid tumor was considered to originate from the remnant of the thyroglossal duct, because of its median location and the presence of the thyroglossal duct cyst near the hyoid bone.
