Thoracoscopic pleural cryobiopsy versus conventional forceps biopsy in diagnosis of exudative pleural effusion of unknown etiology

Background Rigid forceps is commonly used for pleural biopsies during medical thoracoscopy in undiagnosed pleural effusion, and recently, the use of cryoprobe for pleural biopsies was encouraged, as the procedure is effective and safe. Objective This study compared between rigid forceps and cryoprobe pleural biopsies regarding biopsy characteristics, diagnostic yield, and tissue viability in patients with undiagnosed exudative pleural effusion who underwent medical thoracoscopy. Patients and methods A total of 30 patients with undiagnosed exudative pleural effusion were selected for medical thoracoscopy, and pleural biopsies were taken by rigid forceps and cryoprobe in the same setting. All biopsies were processed for histopathology examination. Results Of the 30 patients, 18 (60%) were males and 12 (40%) were females, with mean age of 51.03 years. The most frequent diagnosis was mesothelioma (43.3%) followed by chronic nonspecific inflammation (23.3%), metastatic carcinoma (16.6%) and tuberculosis (16.6%). Biopsies of rigid forceps (mean: 0.8193 cm(2)) were larger than cryoprobe (mean: 0.3377 cm(2)) but with less depth. Tissue viability of cryoprobe biopsies was better than rigid forceps biopsies, and the diagnostic yield of both techniques was the same. Conclusion Cryobiopsies obtained during medical thoracoscopy is technically feasible and safe with high diagnostic value. Biopsies of cryoprobe were smaller than that of rigid forceps but were deeper and with better preserved cellular architecture. These results will encourage the use of cryotechnique for diagnosis of undiagnosed exudative pleural effusion.