The Macroscopic Appearance of Computed Tomography-guided Needle Biopsy Specimens Correlates with Tumor Metastasis in Non-small Cell Lung Cancer.

Background: Computed tomography (CT)-guided needle biopsy is a well-established and dependable procedure for the diagnosis of pulmonary lesions. Some tissue biopsy samples have loose cohesion and disintegrate into tiny pieces before formalin fixation. The purpose of this study was to assess the association between the fresh macroscopic appearance of samples obtained using CT-guided needle biopsy and the clinicopathological features of non-small cell lung cancer (NSCLC).

Methods: A total of 111 patients who underwent CT-guided lung needle biopsy at Osaka City University Hospital between May 2009 and May 2013 were enrolled. Macroscopic appearance was categorized as either loose or tight cohesion. Samples were evaluated using Azan staining to detect collagen fibers. The staining intensity was multiplied by the percentage of positive cells, and the specimen was categorized as having either low (<100) or high expression ( ≥100). Univariate and multivariate logistic regression models were used to evaluate significant covariates for tumor metastasis.

Results: In the cohort of 111 patients, the diagnostic rates in loose and tight cohesions were 82.6% and 87.5%, respectively (p=0.509). In 60 patients diagnosed with NSCLC, Azan staining of collagen fibers was positive in 93.5% of the samples with tight cohesion and 28.6% of the samples with loose cohesion (p<0.001). In the multivariate logistic regression models, distant metastasis was significantly associated with loose cohesion (p=0.026).

Conclusions: These results suggest that the macroscopic appearance of CT-guided biopsy samples correlates with tumor metastasis in NSCLC.