Fig. 2. An incidentally detected thyroid mass in a 62-year-old woman.
A, B. Ultrasonography (A, transverse; B, longitudinal) shows a 2.3-cm hypoechoic solid mass with microlobulated margins, macrocalcifications, and a parallel shape in the left thyroid. The final assessment of this thyroid mass was suspicious for malignancy. C. Ultrasonography-guided fine needle aspiration (US-FNA) cytology (H&E, ×100) demonstrates a low cellular aspirate composed of microfollicles and scattered isolated cells, and the results BRAFV600E mutation analysis were negative. The patient underwent surgery due to the repeated presence of atypia of undetermined significance/follicular lesion of undetermined significance results on follow-up US-FNA, and this mass was confirmed as the follicular variant of papillary thyroid carcinoma on surgery. D. Microscopic images of the tumor (H&E, ×400) shows neoplastic follicles of variable size and shape, with lines near the cells containing eosinophilic colloid, lined by cells with irregular nuclei that show prominent nucleoli, nuclear grooves (arrows) and suspicious pseudoinclusion (arrowhead).