Tuberculosis occurs in the lymphatic glands as elsewhere, by the action of the tubercle bacilli. In some cases there is an obvious propagation of these microbes from an existing local tuberculosis at the periphery, but there are many cases where the primary seat appears to be in the glands.

Primary tuberculosis occurs for the most part in glands connected with mucous membranes having absorbent functions. There is usually at the outset catarrh of the mucous membrane, and it may be presumed that here as elsewhere the exuded products of inflammation are conveyed to the glands. There is no reason to believe that these catarrhs air, in the proper sense, tubercular, but it appears that, along with the inflammatory products, bacilli may be carried from the surface. In susceptible persons these will multiply in the glands and produce a tuberculosis. Such primary tuberculosis mostly occurs in glands whose radicles are connected with the mouth, pharynx, fauces, or intestine, and they are mostly situated about the jaws or neck, or in the mesentery.

The tuberculosis is characterized by the formation of tubercles, which takes place chiefly in the follicular cords. This is accompanied by inflammatory swelling of the gland, just as in other forms of tuberculosis. There is usually a great new-formation of cells which, in the more chronic cases, have mostly the character of epithelioid cells. The amount of swelling and its acuteness vary greatly. There may be a rapid increase of size with redness and other appearances of inflammation, or it may be a slow and indolent process.

Caseous necrosis soon presents itself; at first in a number of centres, but as it proceeds involving more and more of the gland, while the areas coalesce. The extension of the tuberculosis goes on while the older parts are caseous, till the caseous condition comes to involve the whole gland. The completely caseous gland is hard, and on section is firm to the touch; it presents a homogeneous yellow aspect which has been aptly compared to that of the cut surface of a raw potato. Sometimes at the periphery there is a grey transparent zone representing the still advancing tuberculosis, but the caseous condition may extend to the capsule.

The Infective character of the process is manifested by its extension to neighbouring glands. There is sometimes in the neck a complicated tuberculosis of many glands, some lying deeply among the muscles and fasciae. It is noteworthy, however, that there is little or no tendency to extension through the capsule unless it be first ruptured or destroyed. This accords with the fact that tuberculosis does not usually penetrate connective-tissue membranes.

The caseous condition being thus brought about, the disease, so far as the individual glands are concerned, may undergo certain further developments. The caseous matter may simply remain as dead material, surrounded by connective tissue. It often becomes infiltrated with lime salts, and converted finally into a putty-like or stony mass. This is most liable to occur in glands which are protected, such as those of the mediastinum and the mesenteric or other abdominal glands. It is quite common to meet with pultaceous or stony masses in the mediastinum or in the mesentery of adults, these being the obsolete remains of a tuberculosis in childhood.

In the case of superficial glands, which are exposed to mechanical irritation, there is, on the other hand, frequently a Softening associated with inflammation. A process akin to suppuration ensues, in which the matter is partly composed of the debris of the caseous matter and partly of pus. The capsule is perforated and the matter passes towards the surface where it opens as a chronic abscess. In its passage the matter produces a tuberculosis of the parts with which it comes in contact, so that Tubercular sinuses and ulcers are frequent results. It is well known that recovery from this condition is only insured by careful removal of all infective material.

Secondary tuberculosis is very common in glands connected with organs which are the seat of local tuberculosis. This applies especially to the bronchial glands which are always secondarily involved in phthisis pulmonalis. The process here is often a very chronic one, and the glands sometimes instead of caseating become indurated as in chronic inflammation. Indeed, in fibroid phthisis the two processes of induration and tuberculosis often go together. Secondary tuberculosis also arises in the mesenteric and other abdominal glands from tubercular ulcers of the intestine.

The glands are also commonly affected in General tuberculosis. They are the seat of small miliary tubercles, and are generally enlarged and hypersemic.