Table 1. Comparison of reporting systems for thyroid fine-needle aspiration cytology.

Papanicolaou Society of Cytopathology (in 1997)	Japanese Society of Thyroid Surgery (in 2005)	Bethesda system (in 2007, 2017)	Japan Thyroid Association (in 2013)	Japanese Society of Thyroid Surgery (in 2015); Japanese Association of Endocrine Surgery and The Japanese Society of Thyroid Pathology (in 2019)
Unsatisfactory for interpretation	Inadequate	Non-diagnostic or unsatisfactory*	Inadequate	Unsatisfactory
Benign non-neoplastic lesions*	Normal or benign*	(II) Benign	Normal or benign*	Cyst fluid
Cellular follicular lesions				Benign
Follicular neoplasm	Intermediate	(III) Atypia of undetermined significance or follicular lesion of undetermined significance	Indeterminate B (other tumors)	Undetermined significance
Favor benign
Favor malignant
Hürthle cell neoplasm		(IV) Follicular neoplasm or suspicious for a follicular neoplasm	Indeterminate A (follicular neoplasm)	Follicular neoplasm
			A-1: favor benign
			A-2: borderline
			A-3: favor malignant
Suspicious for malignancy	Malignancy suspected	(V) Suspicious for malignancy	Suspicious for malignancy	Suspicious for malignancy
Malignant	Malignant	(VI) Malignant	Malignant	Malignant

*, including cyst fluid.