Primary carcinoma of the bronchus, with an investigation into its early x -ray diagnosis

Abstract

#1. Carcinoma of the bronchus - by which is meant a bronchus of dimensions visible to the bronchoscopist - has a distinct clinical entity of its own, distinct from true lung tumors, with which it has previously been grouped.

#2. Lung and bronchial tumors are moderately rare but are becoming more frequently diagnosed, and may be much more common than at present realized, owing to the frequency with which they are treated as tuberculosis.

#3. A male preponderance and a right-sided maximum incidence seem to indicate a relationship to chronic irritation as an etiological but in the group of cases presented no ship could be established to tuberculosis, influenza, occupational diseases or over -smoking.

#4. The clinical syndrome of the primary bronchial tumor is an absolutely persistent cough with either hemoptysis or scant but blood- stained sputum and the lesion is visible on bronchoscopy. The syndrome of primary parenchymal tumor, a much more latent lesion, is severe, otherwise unexplained, weight loss, associated with vague but constant chest pain, or dyspnoea, or the cough - blood combination of the bronchial group.

#5. The two groups do not separate pathologically in the same manner. The gross pathology of parenchymal includes nodular, lobar and infiltrative forms, while the bronchial are all infiltrative. Microscopically we get all forms of adeno- carcinoma but also some squamous- celled carcinoma, and of the primary bronchial group reported six out of seven cases were of the latter type. This probably represents a metaplasia to an embryonic cell type latent in the development of the trachea and bronchi from the oesophageal bud. The growth tends to be of a highly malignant type.

#6. The radiological literature describes a relatively late case. It groups the appearances as hilar or lober of which the hilar is the more frequent, but at the stage at which the lesion has been previously recognized secondary effects, stenosis, infection, pleural effusion or metastasis, usually complicate the picture.

#7. The early diagnostic picture must be recognized in the routine films of the chest, and therefore a special technique is not called for, although stereoscopic films are of great assistance.

#8. There are three characteristic factors suggestive of bronchial malignancy:

(a) A hilar density, unilateral, occupying the whole hilus, usually just perceptibly separate from the mediastinum, rami- fying out into the parenchyma in irregular strand -like processes and unassociated with any other mediastinal deformity, occurs in the majority of cases. This -may be alone or be associated with one or other of the next two factors.

(b) Atelectasis of a 1.hole or part of a lung without discoverable causal history, is very frequent.

(c) A pseudo -bronchiectasis , an appearance radiologically identical with true bronchiectasis but caused by blood- filled bronchi.

#9. Contrasting with this the parenchymal tumor is less dense, either roughly circular or lobar in shape, rather less infiltrative, and is seldom even apparently hilar in location.

#10. This radiological picture of the early bronchial carcinoma must be distinguished from the following groups of lesions:

(a) OTHER HILAR DENSITIES such as bronchitis, pneumonia, venous engorgement, will give a more diffuse infiltration and will always be bilateral.

(b) APPARENT HILAR DENSITIES such as carcinoma of esophagus, aneurism, and such like, will show a certain definition of edge separating the lesion from the lung, even where there is apparent root infiltration.

(c) TUBERCULOSIS will mostly give the features peculiar to that disease - an apical tendency, an irregular mottling rather than strand -like infiltration and an absence of hilar centering.

(d) OTHER GLAND LESIONS have a definite edge and a crescentic shape rather than the projecting shape of the malignancy, and even if unilateral tend to show a general widening of the media - stinum.

(e) INFLAMMATORY LESIONS are the most difficult as they are so protean in form but they have a general mottled nature, a tendency to multiplicity, an absence of hilar centering and a narrower limitation of the width of the infiltrating edge but never the smooth finished uninfiltrating edge of an stelectasis.

#11. Although there are isolated reported cases of successful lobectomy for parenchymal carcinoma, nothing has yet been done for bronchial: but radium in the bronchus is suggested by the author.