Table 1.

Classification of papillary thyroid carcinoma variants according to biological behavior in the 2015 American Thyroid Association guidelines

Aggressive	Less favorable	Favorable
Tall cell variant	Solid variant	Follicular (encapsulated) variant
Columnar cell	Diffuse sclerosing variant	Cribriform-morular
variant		variant
Hobnail variant		Warthin-like variant