Percutaneous computed tomography guided biopsy of sub-solid pulmonary nodules: differentiating solid from ground...

This study assessed (i) the ability to identify the solid components of part-solid nodules (PSN) during computed tomography (CT) guided lung biopsy (CTGLB), (ii) the ability of CTGLB to assess the invasive nature of a nodule on pathology.

Sixty-nine nodules were studied in 68 patients who underwent CTGLB between 1/1/2014 and 10/31/2015. Diagnostic CT images and CTGLB images were reviewed. On diagnostic CT images, nodules were classified as ground glass nodules (GGN) or PSNs. Nodule size, location, and percentage of solid component were recorded. At the time of biopsy, the ability to visualize the solid component of a PSN, depth of lesion from skin, and ability to identify the needle within the solid component were recorded.

There were 42 (61%) part-solid nodules and 27 (39%) GGNs. During biopsy, it was possible to differentiate the solid from the ground glass components in 35 (83%) PSNs. Fifty-nine (86%) nodules were neoplastic based on biopsy pathology (all non-small cell lung carcinoma). Thirty-nine (66%) were resected. In all cases biopsy pathology and surgical pathology agreed regarding the presence of lung carcinoma. In 6 (15%) cases biopsy pathology demonstrated purely lepidic growth but had some non-lepidic growth on surgical pathology, including 2 cases with acinar growth as a dominant pattern.

In most patients, the solid and ground glass components of a PSN were distinguishable when performing a CTGLB. In a minority of patients, discrepancy was noted between biopsy pathology and surgical pathology regarding the invasive nature of a nodule.