In this review of the modes of invasion in pulmonary tuberculosis, all minor avenues of entrance of the bacillus have been disregarded, and only inhalation and ingestive methods will be considered.
It is generally accepted by pathologists that the first stage of pulmonary tuberculosis is an involvement of the glandular and lymphatic structures of the lungs. Postmortem and roentgenographic evidence seems to prove that tuberculous foci are not established in lung tissue proper until after the peribronchial glands have been seriously damaged by the invading organisms. This is the so-called pretuberculous stage of the disease. In hundreds of reported necropsies, especially of children, foci in the peribronchial glands were the only demonstrable lesions in the body. This analogy has also been reported in comparative pathology, especially in cattle, which have been more carefully examined than other animals. In pseudotuberculosis of sheep and cattle, the pulmonary glands are first involved. Pulmonary