Table 2.

The Bethesda system for reporting thyroid cytopathology: characteristics, management, and risk of malignancy for each diagnostic category

Diagnostic Categories	Characteristics	Usual management	Implied risk of malignancy (%)
Non-diagnostic or unsatisfactory	Cyst fluid only	Repeat FNA with US-guidance	1-4
	Virtually acellular specimen
	Other (hematoma, etc)
Benign	No atypical or malignant cells present, specimen adequate	Clinical follow-up	1
Atypia of unknown significance/Follicular lesion of unknown significance	Atypical cells present, no malignant cells present	Repeat FNA	5-10
Suspicious for follicular neoplasm	Follicular cells present, no malignant cells present	Surgical lobectomy	20-30
Suspicious for malignancy	Cells suspicious for malignancy, specimen adequate	Near-total thyroidectomy or surgical lobectomy	50-75
Malignant	Malignant cells present	Near-total thyroidectomy	100

Table adapted from [14,15,33].