“…Therefore, less invasive techniques such as computed tomographic scanning have been proposed instead (Liippo et al, 1980;Therman et al, 1984;Brion et al, 1985;Khan etal., 1985, Rhoads etal., 1986. However, mediastinoscopy is an effective method for investigating the superior mediastinum and it gives a precise definition of the histology, site, extent of the tumour and the degree of invasion (Jepsen, 1966(Jepsen, , 1967Trinkle et al, 1969).…”