Radiographic and pathological analysis of small lung adenocarcinoma using the new IASLC classification

Area of Science:

• Pulmonary Medicine
• Radiology
• Oncology

Background:

• Small lung adenocarcinomas require accurate classification for optimal treatment.
• The International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society classification system aids in categorizing lung adenocarcinomas.
• Computed tomography (CT) is a key imaging modality for detecting and characterizing lung nodules.

Purpose of the Study:

• To analyze the correlation between CT findings of small lung adenocarcinomas (≤20 mm) and the IASLC/ATS/ERS classification.
• To investigate the association between specific CT features and pathological subtypes of lung adenocarcinoma.

Main Methods:

• Retrospective review of 300 lung adenocarcinomas (≤20 mm) from 295 patients.
• Classification of tumors into air-containing (ratio ≤50%) and solid-density (ratio >50%) types based on CT imaging.
• Investigation of CT findings (air bronchogram, vascular involvement, pleural tags, notches, spiculation) against pathological results.

Main Results:

• Of 142 air-containing lesions, 114 were adenocarcinoma in situ (AIS) and 28 were minimally invasive adenocarcinoma (MIA). No invasive adenocarcinomas were found in this group.
• Of 158 solid-density lesions, 30 were AIS, 24 were MIA, and 104 were invasive adenocarcinoma.
• Notches and pleural tags were significantly more common in invasive adenocarcinomas (p < 0.05).

Conclusions:

• Air-containing small lung adenocarcinomas are predominantly AIS or MIA, with no invasive types identified.
• The presence of notches and pleural tags on CT scans is a significant indicator of invasive adenocarcinoma.
• CT imaging features can aid in differentiating subtypes of small lung adenocarcinomas, guiding clinical management.