[Establishment of T3 (T4) in the TNM classification of lung cancer]

The diagnosis of T3 (T4) extension of a lung tumor according to the TNM classification system means that the patient has reached stage 3 with a very poor prognosis. To establish the exact extent of a tumor standard chest X-rays, tomograms and even CT scan may not suffice, and, depending on the situation, endoscopy, ultrasonography, NMR or diagnostic pneumothorax should be employed. Extension T4, corresponding to malignant pleural effusion, which has been added recently (1987) to the UICC classification, may require thoracocentesis, pleural biopsy or even pleuroscopy.