Cryobiopsy In Flexi-Rigid Pleuroscopy in a Region with Low Mesothelioma Prevalence

Background: The use of conventional flexible forceps during flex-rigid pleuroscopy can be challenging when sampling hard and thickened pleura. Pleuroscopic cryobiopsy is an emerging field, with various early studies demonstrating good yield and minimal complications. Objectives: To review the authors’ early experience of pleuroscopic cryobiopsy in their centre and highlight its utility in the diagnosis of mesothelioma. Method: Six cases of undiagnosed pleural effusion that underwent pleuroscopic cryobiopsy via flexi-rigid pleuroscopy between July 2017 and June 2019 were retrospectively analysed. Results: The cohort had a median age of 59 years, consisting of two females and four males with a median age of 57 years. Mean (aggregate) tissue sample diameter was 9.2±1.9 mm. Cryobiopsy established a definitive diagnosis in all six cases: one case of malignant mesothelioma, one pleural tuberculosis, two small cell carcinomas, and two adenocarcinomas. Immunohistochemical staining was performed in all five of the malignant samples (100%). There were no major complications reported. Conclusions: Based on the case series, pleuroscopic cryobiopsy is a feasible adjunct to conventional forceps biopsy, a safe procedure in the authors’ setting, gives high diagnostic yield, and enables differentiation between the different causes of exudative pleural effusion. A large, prospective study is required to validate this retrospective series.