“…Some cases have undergone spontaneous resolution (Doub and Shea, 1960;Navani, 1966;Moore, 1968) and in others resection has been followed by recurrence (Sames, 1964). Forgacs et al (1973 predicted that by breatbing a high concentration of oxygen the total tension of gases at the venous end of the capillaries would be lowered, thereby increasing the rate of diffusion of gas from the cysts (Nunn, 1969).…”