CT-Guided Core-Needle Biopsy of Pulmonary Lesions Associated With Cystic Airspaces: A Case-Control Study

: Background: Concern may exist that pulmonary lesions associated with cystic airspaces are at risk of increased biopsy complications or lower biopsy accuracy given challenges in targeting tissue abutting or intermingled with the cystic airspaces. Objective: To evaluate the safety and diagnostic performance of CT-guided core-needle biopsy (CNB) of pulmonary lesions with cystic airspaces. Methods: This retrospective study included 90 patients (median age, 69.5 years; 28 female, 62 male) who underwent CT-guided CNB of pulmonary lesions associated with cystic airspaces (based on review of procedural images) from February 2010 to December 2022 and a matched control group (2:1 ratio) of 180 patients (median age, 68.0 years; 56 female, 124 male) who underwent CNB of noncystic noncavitary lesions during the same period. The groups were compared in terms of complications, nondiagnostic biopsies (i.e., nonspecific benignities, atypical cells, or insufficient specimens), and CNB diagnostic performance for detecting malignancy using as reference the final diagnosis from a joint review of all available records. For lesions associated with cystic airspaces that underwent surgical resection after CNB, histologic slides were re-reviewed to assess cystic airspace etiology. Results: The final diagnosis was malignant in 90% (81/90) of lesions associated with cystic airspaces and 92% (165/180) of noncystic noncavitary lesions. Patients with lesions associated with cystic airspaces and patients with noncystic noncavitary lesions showed no significant difference in frequencies of complication (all: 40% [36/90] vs 38% [68/180], p=.79; major: 4% [4/90] vs 6% [10/180], p=.78; minor: 36% [32/90] vs 32% [58/180], p=.59), frequency of nondiagnostic biopsies (12% [11/90] vs 9% [16/180], p=.40), or diagnostic performance (accuracy: 94.% [85/90] vs 97% [175/180], p=.50; sensitivity: 94% [76/81] vs 97% [160/165], p=.50; specificity: 100% [9/9] vs 100% [15/15]; p>.99), respectively. All false-negative results for malignancy in both groups occurred in patients with nondiagnostic CNB results. Among lesions associated with cystic airspaces that were resected after CNB (all malignant), the cystic airspaces most commonly represented tumor degeneration (22/31, 71%). Conclusion: CT-guided CNB is safe and accurate for assessing pulmonary lesions associated with cystic airspaces. Clinical Impact: CNB may help avoid a missed or delayed cancer diagnosis in pulmonary lesions with cystic airspaces.