Efficacy and safety of transbronchial lung biopsy for the diagnosis of lymphangioleiomyomatosis: A report of 24 consecutive patients

ABSTRACT Background and objective Lymphangioleiomyomatosis (LAM) is a diffuse cystic lung disease that occurs in women of childbearing age. LAM can be diagnosed on a clinical basis in patients with typical high‐resolution computed tomography (HRCT) patterns and at least one other corroborating disease feature, such as chylothorax, angiomyolipoma, tuberous sclerosis complex or elevated serum vascular endothelial growth factor (VEGF)‐D. However, patients who do not meet these criteria require tissue confirmation for a definitive diagnosis, and the utility of methods that are less invasive than surgical lung biopsy, such as transbronchial lung biopsy (TBLB), are not well studied. We retrospectively studied the efficacy and safety of TBLB for the diagnosis of LAM. Methods From January 1991 to August 2015, 131 consecutive LAM patients were prospectively registered in our study, and a TBLB was conducted for 24 patients. We retrospectively studied the yield and safety of TBLB in this cohort. Results All 24 patients were women; the median age was 42 years. HRCT showed multiple round thin‐walled cysts diffusely scattered throughout the lungs. The median level of serum VEGF‐D was 2109 pg/mL. Characteristic pathological findings for LAM were identified in 17 patients (70.8%) by two expert pathologists. The %predicted value for diffusing capacity of carbon monoxide was significantly lower in the 17 TBLB‐positive LAM patients compared to the seven TBLB‐negative LAM patients (P = 0.046). There were no serious adverse events such as pneumothorax or uncontrollable bleeding due to TBLB. Conclusion TBLB is a safe and effective method for the pathological diagnosis of LAM. The diagnosis yield for lymphangioleiomyomatosis by transbronchial lung biopsy (TBLB) was 70.8%. The yield of TBLB was higher in patients with a reduced diffusing capacity, suggesting that an adequate disease burden is required for this approach. The procedure seems safe, as no serious adverse events such as pneumothorax or excessive bleeding were observed.