Table 3.

IASLC Staging: Pathologic Criteria¹³

Atypical Adenomatous Hyperplasia	Adenocarcinoma in Situ	Minimally Invasive Adenocarcinoma	Invasive Adenocarcinoma
•Total size ≤ 0.5 cm •No invasive component	•Size < 3 cm •Pure lepidic (ground-glass) •No invasive component (acinar, papillary, micropapillary, solid, colloid, enteric, fetal, invasive mucinous)	•Size ≤ 3 cm •Predominantly lepidic •Invasive component ≤ 5 mm in any one focus •Exclusion criteria: lymphatic, blood vessel, or pleural invasion; tumor necrosis; airspace spread •T1mi	•T1a: solid component, 0.6-1 cm •T1b: solid component, 1.1-2 cm •T1c: solid component, 2.1-3 cm

IASLC = International Association for the Study of Lung Cancer.