The value of virtual bronchoscopic navigation and radial endobronchial ultrasound-guided transbronchial lung cryobiopsies for pulmonary lymphangitic carcinomatosis

BACKGROUND: Pulmonary lymphangitic carcinomatosis (PLC) is characterized by malignant infiltration into lung lymphatic channels from a primary site and is often observed in advanced malignant tumors. This study aimed to evaluate the diagnostic yield of transbronchial lung cryobiopsy in PLC guided by radial endobronchial ultrasound and virtual bronchoscopic navigation (VBN). METHODS: This prospective study enrolled 40 patients with clinical and radiologic features indicating PLC. The radial endobronchial ultrasound probe was initially advanced to the region of interest of the desired lobe near the pleura with guidance by VBN. Transbronchial lung biopsy and transbronchial lung cryobiopsy were both performed in the same ROI of all patients with the obtained samples being sent to the pathology laboratory for diagnostic analysis. Procedural complications were recorded. RESULTS: The average number of transbronchial lung biopsy and transbronchial lung cryobiopsy specimens were 4 (3 to 6) and 2 (1 to 3), respectively (t=10.43, P<0.01), with the corresponding mean diameters per biopsy being 3.7 and 8.7 mm (t=12.37, P<0.01). The diagnostic yields of transbronchial lung biopsy and transbronchial lung cryobiopsy were 70% (28/40) and 92.5% (37/40), respectively. The final positive predictive values of transbronchial lung cryobiopsy and transbronchial lung biopsy for PLC were 94.4% (34/36) and 77.8% (28/36), respectively (χ(2)=23.94, P<0.01). Further, 52.2% (12/23) and 81.5% (22/27) of the patients in the transbronchial lung biopsy and transbronchial lung cryobiopsy groups, respectively, were diagnosed with non-small lung cancer after further molecular analysis (χ(2)=19.56, P<0.01). Only 2 (5%) cases presented postoperative pneumothorax. Moreover, 0 (0%), 3 (7.5%), and 17 (42.5%) patients presented severe, moderate, and mild bleeding, respectively. There were no other adverse events or deaths. CONCLUSIONS: Transbronchial lung cryobiopsy with the guidance of radial endobronchial ultrasound and VBN without fluoroscopy has a good diagnostic yield for PLC; moreover, it allows one to obtain adequate and intact tissue samples for further molecular analysis.