Figure 6.

Oncocytic Classic Papillary Thyroid Carcinoma. A classical papillary thyroid carcinoma has oncocytic cytology of the columnar cells lining a complex papilla (A). In this example, the oncocytic cells are more polygonal and cuboidal (B). When the oncocytic cells are crowded, there is a superficial resemblance to tall cell papillary thyroid carcinoma, but careful inspection shows that the height-to-width ratio does not exceed 3:1 (C). The oncocytic cells can have variable shapes and sizes (D), however in all of these examples, the nuclear features of papillary caricnoma are readily appreciated.