Clinicopathologic and Longitudinal Imaging Features of Lung Cancer Associated with Cystic Airspaces: A Systematic Review and Meta-Analysis

Abstract

Background: Lung cancer with cystic airspaces (LC-CAS) is an uncommon presentation of primary lung malignancy. Due to their rarity and atypical appearance, there can be delays in diagnosis and treatment.

Evidence acquisition: We searched for published papers on the clinicopathologic and imaging features of LC-CAS and included studies based on predefined criteria. We extracted the clinicopathologic characteristics of the patients with LC-CAS and computed tomography (CT) imaging features of LC-CAS and performed pooled analysis for reported continuous and categorical data.

Evidence synthesis: The analysis included 8 original research studies with combined 341 patients with LC-CAS (weighted mean age: 61.8 years; range: 30-87 years). Majority had stage I disease (134/217, 61.8%). The most common histologies were adenocarcinoma (289/328, 88.1%) and squamous cell carcinoma (30/328, 9.1%). The cysts in LC-CAS commonly had non-uniform (104/114; 91.2%) and thick (83/222; 37.4%) walls, had irregular margins (53/142; 37.3%), and were multilocular (99/272; 36.4%). Most LC-CAS had a nodule or soft tissue component (210/328; 64.0%). Over time, most LC-CAS had development or enlargement of the solid component (61/89, 68.5%), approximately half (43/89, 48.3%) had interval wall thickening, and a minority evolved into completely solid masses or nodules (11/89, 12.4%). The cystic component can increase (36/89, 40.4%), decrease (28/89, 31.5), or remain stable (24/89, 27.0%) in size.

Conclusion: Lung cancer should be suspected in cystic lung lesions with associated wall thickening or nodularity, and the index of suspicion should be further raised if wall thickening increases or nodule develops. The cystic component in LC-CAS may enlarge, remain stable, or decrease in size over time; stability or decreased size of the cyst should not be taken as a sign of benignity. These lesions can be indolent and close and long-term follow up with imaging should be considered if these lesions are not biopsied or resected.