Table 1.

Categories and definitions of the JLCS-JSCC system^*

Step	Diagnostic category	Definition
First step	Adequate Inadequate	Adequate for cytological evaluation Inadequate for cytological evaluation
Second step (if adequate in the first step)	NM	The absence of malignancy and any significant cellular atypia
	ACs	Cytomorphological aberrations that are greater than those of the NM category but less than those assignable to the SM category
	SM	Cytomorphological features that are suspicious but not diagnostic of carcinomas due to insufficient features characteristic of carcinomas and/or an insufficient number of ACs to be diagnosed as ML
	ML	Cytomorphological features that are unequivocally malignant
Third step		(Pathological classification is made if possible)

JSCC, Japan Lung Cancer Society; JLCS, Japanese Society of Clinical Cytology; NM, negative for malignancy; AC, atypical cells; SM, suspicious for malignancy; ML, malignancy.

^*The JLCS and JSCC cytology reporting system for lung carcinoma