Incidental, subsolid pulmonary nodules at CT: etiology and management

Area of Science:

• Pulmonary imaging and diagnostics
• Thoracic oncology
• Pathology and classification of lung neoplasms

Background:

• Subsolid nodules (SSNs) are frequent incidental findings on computed tomography (CT), presenting diagnostic challenges.
• The differential diagnosis for SSNs is broad, encompassing infectious, inflammatory, and neoplastic processes.
• Lung adenocarcinomas, particularly the former bronchioloalveolar cell carcinoma (BAC) subtype, often manifest as SSNs.

Purpose of the Study:

• To review the International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society 2011 classification of lung adenocarcinomas.
• To correlate specific histologic subtypes with characteristic CT findings of SSNs.
• To outline current diagnostic, treatment, and follow-up recommendations for SSNs based on CT features.

Main Methods:

• Review of the 2011 international multidisciplinary classification system for lung adenocarcinoma.
• Discussion and illustration of CT imaging features associated with new adenocarcinoma subtypes.
• Synthesis of current clinical guidelines for managing SSNs detected on CT.

Main Results:

• The revised classification system replaces the term bronchioloalveolar cell carcinoma (BAC) with more specific histologic subtypes.
• Distinct CT imaging characteristics are associated with these newly defined adenocarcinoma subtypes.
• CT findings are crucial for guiding the diagnostic workup, treatment decisions, and follow-up strategies for SSNs.

Conclusions:

• The updated lung adenocarcinoma classification provides a framework for understanding SSN radiologic-pathologic correlations.
• Accurate interpretation of CT findings in SSNs is essential for appropriate patient management.
• Adherence to current recommendations based on CT features improves the diagnostic and therapeutic approach to SSNs.