Acute Miliary Tuberculosis

This condition has been discussed at page 313. The tubercular virus, being present abundantly in the blood, produces very marked lesions in the lungs. As the virus is brought by the blood, the lesions are generally homogeneously distributed throughout both lungs, and are intimately related to the finer branches of the pulmonary artery.

The lungs are found studded from apex to base with innumerable small bodies, generally whitish in colour. There is in addition a general hyperemia of the lungs.

Under the microscope it can be seen in most cases that the tubercles are formed in connection with arteries. A small artery will generally be seen at the edge of or running directly into a tubercle, and it is not uncommon to find a tubercle in the wall of an artery, as in Figs. 131 and 132, pp. 314, 315. The tubercle has the usual structure, which is frequently obscured in the central parts by caseous necrosis.

The lung tissue generally shows some reaction in the neighbourhood of the tubercles. The alveoli are frequently occupied by catarrhal cells as in phthisis, and there is very often blood in them. The latter is so abundant in some cases as to give a very striking character to the sections. As the cases are very acute and death occurs early, we practically never find softening of the tubercles or formation of cavities.

Syphilis is a very rare affection of the lungs, especially in adults. It is somewhat more common in new-born children, in whom it may be one of the manifestations of hereditary syphilis. In adults gummata have been observed in a few cases. They are surrounded by connective tissue in the usual way, and they may be partially softened so as to form cavities. The gummata are usually of small size.

White pneumonia is a name given to the condition met with in infants in congenital syphilis. It is a condition in which extensive tracts of lung tissue are condensed and infiltrated by a new-formation of connective tissue, the condition resembling that in chronic interstitial pneumonia.

Actinomycosis, when affecting the lungs, presents lesions which may resemble those of tuberculosis somewhat closely. As in tuberculosis the microbe reaches the lungs by the bronchi, and it sets up a bronchitis and lobular pneumonia. There is not a caseous necrosis of the products, but rather a more direct softening with fatty degeneration and suppuration, resulting in the formation of cavities. In other cases, however, the conditions may resemble those of fibroid phthisis, there being over an extensive tract of lung a new-formation of granulation tissue which develops into connective tissue and goes on to shrinking.

The disease tends to go beyond the lung to the pleura, pericardium, muscles of the chest, skin, etc. The peculiar microbe is present, and in some cases it has been distinguished in the expectoration.

Glanders may affect the lung by extension from the nares and air-passages, possibly also by the blood. It leads to local inflammatory foci, which may be small or large. The inflammation is usually acute and abscesses result, but sometimes there is a more chronic affection with caseation and formation of cavities.

Literature

Syphilis - Virchow, Die krankhaften Geschwtilste, ii., 1865; Hillkh, Charite-ann., 1882, 1884; Heller, Deut. Arch. f. klin. Med., 42, 1888; Councilman, Johns Hopkins Hosp. Bull., ii., 1891; Fowler, Allbutt's System of Med., v., 1898. Actinomycosis - Lindt, Correspbl. f. schweiz. Aerzte, 1889. Glanders - Leclanchk et Montane, Ann. de l'lnst. Pasteur, vii., 1893.