Diagnostic Value of Bronchoscopic and Thoracoscopic Frozen Section Biopsies in Patients With Pleuropulmonary Tumors

All included patients will be subjected to the following:

• Full medical history and clinical examination.
• Routine investigation: complete blood count, liver function test, kidney function test, coagulation profile and arterial blood gases.
• Imaging:
• Chest X-ray.
• Chest Ultrasound to evaluate the amount of pleural effusion and the presence of adhesions.
• MSCT Chest with contrast.
• Pleural fluid study including serum pleural albumin gradient (SPAG), Pleural fluid PH and pleural fluid cytology.

Flexible Bronchoscopy (PENTAX, EB-1970TK 3.2) will be done after instillation of lidocaine 2% by spray and procedural sedation with midazolam (0.01-0.1mg\kg) with continuous monitoring for O2 saturation, heart rate, blood preesure and respiratory rate throughout the procedure. The bronchoscope will be introduced into the nasal cavity and advanced to the level of the vocal cords. Lidocaine 2% will be instilled through the bronchoscope to the vocal cords and tracheobronchial tree to minimize cough. Assessment of the appearance and movement of the cords will be done. As the bronchoscope is advanced beyond the vocal cords, careful inspection of the entire airway will be done. Biopsies from abnormal endobronchial lesions or mucosal abnormalities will be performed. Any evidence of narrowing or dynamic collapse, will be assessed. The biopsies will be sent for both frozen section and permenant paraffin section. Once sufficient tissue sample is confirmed the procedure will be terminated. Final assessment of the airway will be performed to ensure adequate hemostasis.

Medical thoracoscopy using (Karl Storz Heine optical 6mm, Tübingen Germany) with single-port-of-entry technique will be performed under local anesthesia and conscious sedation using midazolam (0.01-0.1mg\kg) or mepredine (0.9mg\kg). The point of entery will be guided with chest ultrasonography. Vertical incision will be made with the scalpel (usually near the midaxillary line), through the skin and subcutaneous tissue, appropriate to the size of the used trocar, usually of approximately 10 mm, parallel with and in the middle of the selected intercostal space. Then the trocar will be inserted in a corkscrew motion until the sudden release of resistance (after passing the costal pleura) is felt, while holding the handle of the trocar firmly in the palm of the hand, as index finger is extended. Under direct vision with the thoracoscope, introduction of pneumothorax will be performed and all pleural fluid will be removed and the pleural cavity will be inspected. Suspicious areas (irregularities, nodules, hyperemic lesions) will be biopsied through the working channel of the thoracoscope using the forceps biopsy.The biopsies will be sent for both frozen section and permenant paraffin section. Intraprocedual confirmation of malignancy will be followed immediately with pleurodesis. An intercostal drain will be placed with underwater seal drainage to drain residual air and fluid from the pleural cavity, allowing the lung to re -expand. The indications for removal of chest tubes will be absence of air leakage and cessation of fluid flow (100-150 mL daily).

The specimen prepared for frozen section will be placed on a metal tissue disc which is then secured in a chuck and frozen rapidly to about -20 to -30 °C. The specimen will be embedded in a gel like medium called optimal cutting temperature compound (OCT) and consisting of polyethylene glycol and polyvinyl alcohol. Subsequently it will be cut frozen with the microtome portion of the cryostat, the section will be picked up on a glass slide and stained (usually with hematoxylin and eosin, the H\&E stain).