Fig. 4. Representative microscopic images of core needle biopsy specimens. A. Paucicellular fibrotic nodule with calcification shows few atypical follicular cells with nuclear atypia and can be diagnosed as papillary carcinoma. Shown at × 12.5 original magnification (left), × 100 original magnification (middle) and × 400 original magnification (right). Hematoxylin and eosin stain was used. B. Core needle biopsy specimen consists of microfollicular proliferative lesion, fibrous capsule, and surrounding normal parenchyma. In high-power view, follicular cells have no nuclear atypia. This case can be diagnosed as follicular neoplasm. Shown at × 40 original magnification (left) and × 400 original magnification (right). Hematoxylin and eosin stain was used. C. Case of classic papillary carcinoma. Specimen shows papillary proliferative lesion with typical nuclear features of papillary carcinoma. Shown at × 12.5 original magnification (left) and × 400 original magnification (right). Hematoxylin and eosin stain was used. Fig. 4. Representative microscopic images of core needle biopsy specimens. A. Paucicellular fibrotic nodule with calcification shows few atypical follicular cells with nuclear atypia and can be diagnosed as papillary carcinoma. Shown at × 12.5 original magnification (left), × 100 original magnification (middle) and × 400 original magnification (right). Hematoxylin and eosin . . . Korean J Radiol. 2017 Jan-Feb;18(1):217-237. https://doi.org/10.3348/kjr.2017.18.1.217