“…They are generally 1-2 cm in diameter, but may be considerably larger; in Case 3 of Christie (1954) a massive encapsulated nodule in the right upper lobe was 7 cm in diameter, and in a case reported by Mattingley (1964) a thoracotomy was undertaken on a provisional diagnosis of carcinoma. Not infrequently they cavitate, the necrotic central part presumably undergoing liquefaction and being discharged into an airway (Dumas et al 1963, Locke 1963, Noonan et al 1963, Yates 1963, Portner & Gracie 1966 Ramirez-R & Campbell 1966, Stengel et al 1966, Burrows 1967, Panettiere et al 1968). They may also ulcerate into the pleura causing spontaneous pneumothorax or hydropneumothorax (Morgan & Wolfel 1966, Portner & Gracie 1966, Burrows 1967, Rubin et al 1967 or even pyopneumothorax (Davies 1966); and in several cases, mentioned below, pleural effusions and subpleural or pleural nodules have co-existed.…”