A woman in her 50s was admitted to our hospital with a 5-week history of a nontender mass on the right side of the neck. No husky voice, dysphagia, or odynophagia were reported. A physical examination revealed a 2 × 2-cm tumor over the right side of her neck at level III. Bilateral vocal fold movements were normal. The free thyroxine level was 0.94 ng/dL, and the thyroid-stimulating hormone level was 1.33 mIU/mL. (To convert thyroxine to picomoles per liter, multiply by 12.871.) Fine-needle aspiration (FNA) was performed, and cellular changes suspected to be malignant neoplasm were reported. Computed tomographic images of the neck showed enlargement of the right side of the thyroid gland with retrosternal extension, and total thyroidectomy was arranged (Figure, A, arrowhead). During the operation, the tumor was found to extend to the thoracic cavity and to be attached tightly to the right carotid artery. The surgical specimen showed a 6.5 × 6.0 × 2.8-cm dark brown and elastic mass replacing most of the right side of the thyroid. The tumor possessed a rough surface, and focal hemorrhages were also noted. The thyroid tumor appeared to be composed of broad anastomosing islands of tumor cells separated by desmoplastic stroma (Figure, B). No lymphovascular invasion or extrathyroidal extensions were identified. The tumor cell nests were well demarcated, with smooth borders in some areas, and a syncytial pattern could also be observed with irregular borders in other areas. Microscopically, the tumor was composed of confluent nests and lobules of epithelioid and spindle-shaped cells surrounded by fibrous septa. The tumor cells had vesicular nuclei and eosinophilic cytoplasm. Marked anisonucleosis with irregular nuclear contours were also noted. The nuclear-cytoplasmic ratios were very high, and the pleomorphic tumor cell nuclei along with a small nucleoli were evident. Increased lymphocyte and plasma cell infiltration around and within the tumor cell nests was seen. Immunohistochemical studies revealed that the tumor cells were positive for cytokeratin (Figure, C), CD5 (Figure, D), and p63 but were negative for thyroid transcription factor-1.
Hsu H, Lin Y, Yeh C, Huang C, Cheng C, Hung S. Nontender Mass on the Right Side of the Neck. JAMA Otolaryngol Head Neck Surg. 2014;140(3):269-270. doi:10.1001/jamaoto.2013.6293