Tuberculous cavities in the apex of the lower lobe.

It has long been recognized that tuberculous cavities may occur in the apex of the lower lobe of the lung, often known as the dorsal lobe (Kidd, 1886; Fowler, 1888 ; Sweany and others, 1931). Steen (1945) has reviewed the many publications on basal tuberculosis, but no paper I have traced has been concerned exclusively with tuberculous cavities of the dorsal lobe; most authors do not differentiate between the various distributions of basal tuberculosis, though some (Reisner, 1935; Wiedman and Campbell, 1937; Cohen, 1945) have stated that in the majority of their cases the lesion was at the apex of the lower lobe. In 18 publications quoted by Steen (1945) the incidence of basal disease averaged 1.5% of all cases of tuberculosis, varying from 0.15 to 18.3% in different papers. In a careful study with stereoscopic radiographs Sweany and his colleagues (1931) found that 13.7% of 268 "primary reinfection cavities " were situated in the apex of the lower lobe. Almost all authors are agreed that basal tuberculosis is much commoner in women. This is attributed to the smaller respiratory excursion of the diaphragm (Reisner, 1935 ; Ossen, 1944). Lesions are reported most frequently on the right side of the chest, which is said to be due to the lesser movement of the right leaf of the diaphragm and the more vertical direction of the right main bronchus (Reisner, 1935), but it is possible that lesions on the left have often been missed because they are hidden behind the heart in the usual postero-anterior radiograph. The prognosis of basal tuberculosis in general was formerly regarded as very poor (Kidd, 1886; Dunham and Norton, 1927). Since the introduction of artificial pneumothorax a less gloomy view has been taken by some writers (Reisner, 1935; Weidman and Campbell, 1937; Busby, 1939; Cohen, 1945), but the follow-up period in these reports has usually been brief and spreads of disease common. Hawkins and Thomas (1946) obtained poor results with artificial pneumothorax, -but were impressed by the use of artificial pneumoperitoneum combined with phrenic