Safety and efficacy of cryobiopsy for the diagnosis of lymphangioleiomyomatosis compared with forceps biopsy and surgical lung biopsy.

Background: Transbronchial lung forceps biopsy (TBFB) is recommended before a surgical lung biopsy (SLB) when a definitive diagnosis of lymphangioleiomyomatosis (LAM) is required for patients without any additional confirmatory features. Transbronchial lung cryobiopsy (TBCB) has been suggested as replacement test in patients considered eligible to undergo SLB for the diagnosis of interstitial lung diseases. The efficacy and safety of TBCB were compared with that of TBFB and SLB in the diagnosis of LAM.

Methods: A retrospective analysis was conducted on 207 consecutive patients suspected with LAM in the First Affiliated Hospital of Guangzhou Medical University from 2005 to 2020.

Results: The difference in diagnostic rate of patients suspected with LAM between TBCB (20/30, 66.7%) and TBFB (70/106, 66.0%) groups was not significant (p = 0.949). One patient performed TBCB with negative pathological results could be diagnosed exclusively after SLB. LAM diagnosis was confirmed by surgical pathological findings in 3 TBFB-negative patients. More patients with minimal cystic profusion were diagnosed with LAM by TBCB (5/19, 26.3%) and SLB (11/39, 28.2%) than by TBFB (3/61, 4.9%) (TBCB vs TBFB: p = 0.04, SLB vs TBFB, p < 0.001). The difference between the severity of cystic lung disease in patients diagnosed with LAM through TBCB and SLB was not significant (p > 0.05). One pneumothorax, 8 mild bleeding and 1 moderate bleeding were observed in TBCB. One pneumothorax, 15 mild bleeding and 1 moderate bleeding occurred after TBFB.

Conclusion: Compared to TBFB, TBCB is safe and effective in diagnosing LAM at a higher diagnostic rate in patients with minimal cystic profusion.