Table 1.

Development of definition of ASC

Author	Year of publication	Main points
The Japan Lung Cancer Society1	1978	Components of SCC and ADC should account for at least 20% of the tumor
WHO2	1981	Diagnosis of ASC can be established once components of ADC and SCC are identified
Fitzgibbons and Kern3	1985	Diagnosis of components of ADC and SCC must be based on the corresponding typical characteristics
WHO6	1999	Each component constitutes at least 10% of the tumor under a light microscope

Abbreviations: ADC, adenocarcinoma; ASC, adenosquamous carcinoma of the lung; SCC, squamous cell carcinoma.