Medical Thoracoscopy in Malignant Pleural Effusion

Malignant pleural effusion (MPE) is a common complication of advanced malignancies, often resulting in significant morbidity and impaired quality of life. In most cases, pleural fluid cytology remains negative. In the era of targeted cancer therapy, pathologists expect larger tissue samples. Therefore, medical thoracoscopy (MT) has gained popularity for adequate tissue sampling under supervision. During MT, various morphological pleural lesions were identified, yet their histopathological associations remain unknown. This study aimed to assess the diagnostic yield of medical thoracoscopy and the complications associated with the procedure. We also observed various morphological lesions in MPE and their histopathological associations.

This was a single-center, hospital-based, prospective cross-sectional study conducted in the Department of Pulmonary Medicine, Veer Surendra Sai Institute of Medical Sciences and Research (VIMSAR), Burla, India. Patients with undiagnosed pleural effusion underwent MT. During the procedure, the lesions were morphologically characterized, and samples were collected for histopathological examination (HPE).

A total of 87 patients underwent medical thoracoscopy using a rigid thoracoscope (Optymed®, Delhi, India), out of which 72 patients had malignant effusion and seven patients had tuberculous effusion. Eight patients had nonspecific inflammation. The diagnostic yield of medical thoracoscopy in this study was at least 90.8% (95% CI: 84.8%-96.8%). Seventy-two patients were evaluated for histopathologic and morphologic association. The most common procedure-related complication was pain at the incision site (87, 100%, median Visual Analogue Scale (VAS): 5), followed by desaturation. The mean fall in saturation was 5.13% (±33.78%). We did not observe any serious adverse effects related to rigid MT. The mean age of the patients was 54.17 (±15.17) years. Among MPE, pleural-based nodules (46, 63.9%), followed by adhesions (27, 37.5%), were the most common findings during MT. Other noted lesions included masses (26, 36.12%), plaques (22, 30.56%), and strands (19, 26.39%). Nodules were significantly associated with metastatic adenocarcinoma (p<0.01). Adhesions and plaques were commonly linked with pleural abnormalities in malignant mesothelioma (p<0.01). Masses were most frequently associated with lymphomas (p<0.01) and undifferentiated carcinoma (p<0.01). Small cell carcinoma comprised only five patients among MPE and was associated with strands (p<0.01).

Medical thoracoscopy is a valuable tool in evaluating and managing malignant pleural effusion. Its high diagnostic accuracy, therapeutic capabilities, and favorable safety profile make it the procedure of choice in appropriate clinical settings. Specific morphological patterns may be observed in different pleural malignancies.