1. This study is based on a series of 41 consecutive cases of tuberculoma of the lung, seen at the Brompton Hospital for Diseases of the Chest, in whom, with the exception of 7 cases subjected to pulmonary resection, a follow-up, varying between 3 and 15 years, has been obtained.
This series, by virtue of inadequacy in numbers, short duration of follow -up, and other deficiencies, does not constitute a scientific basis for any final conclusions on the subject, but it serves to throw some light on the various problems associated with these lesions.
2. Tuberculoma of the lung is defined. The term should be used only to denote a radiological entity - the rounded, homogeneous, pulmonary opacities of tuberculosis. When employed in this fashion, it provides the most acceptable descriptive term for these lesions.
3. The diagnostic problem in all its aspects is discussed, with particular reference to the difficulties of differential diagnosis. Confusion with primary bronchogenic carcinoma is the greatest hazard, and clinical differentiation is often difficult. The history of illness, age of the patient, sputum findings, and the radiographic characteristics of tuberculomata are the salient diagnostic accessories.
The importance of tomography is stressed, and its use advocated as a. routine measure. Not only does it help to elucidate the true radiographic nature of the lesion, but it may determine the presence of other tuberculous disease in the lungs or hilar adenopathy - findings of much importance in relation to both diagnosis and treatment.
Exploratory thoracotomy as a diagnostic measure is deplored, as is routine resection in every doubtful case. Operation, however, is undoubtedly justified, when, after most careful assessment, the scales weigh in favour of primary neoplasm.
4. The natural history of these foci has received but cursory attention in the past, and yet the predominant opinion of present -day observers accords to them a poor prognosis unless radically treated.
In this series, 31, (91 %), of the 34 cases treated conservatively, were alive and well at the end of surveillance. There were no deaths, but the remaining 3 patients have active pulmonary tuberculosis. Despite this good prognosis, 50% demonstrated instability of . the lesion at some time, in the form of enlargement, cavitation, or the development of fresh disease; the remainder healed without event.
These results are similar to those obtained by Eriksen, in Norway, in the only other study of this kind.
5 Their pathology is varied and three distinct patterns are observed:- (a) post -primary Gaseous pneumonia, (b) inspissated cavity, and (c) primary focus. Differentiation of cases into these histo-pathological groups by clinical and radiological means is normally impossible; and even microscopy can fail.
6. The therapeutic problems presented by tuberculomata are such that it is often a matter of considerable difficulty to envisage the best line of treatment for the individual patient.
In recent years, a certain bias towards resection has developed, encouraged by reports of good surgical results. In the literature, little if any criticism has been levelled against its use. That it has a part to play in therapy is admitted, but evidence has been produced in favour of restriction of its sphere. It has no place in the symptomless patient with the unchanging lesion, but, in selected cases, where activity is manifest, it may allow a more rapid return to normal life.
Finally, a plea is made for a more optimistic outlook as regards the natural history of tuberculomata and in favour of a more conservative therapeutic policy. Bed rest, possibly assisted by minor collapse, will turn the average active case towards cure. With the healing case, no interference is necessary.