In the abdomen the mesenteric glands are most exposed to disease, and when infected through the intestinal tract they assume the form of large flattened masses arranged along the mesentery.
In the digestive tract, as in the trachea and bronchi, tuberculosis has a marked tendency to assume the ulcerative form. Disseminated or aggregated tubercles develop in the thickness of the mucous membrane, and, after rapidly softening, become ulcerated. The nature of these lesions can only be determined by noting their character and examining the discharge.
Fig. 276.—Tuberculosis of lymphatics. PG, Left lung; PD, right lung; TT, tuberculous œsophageal lymph glands; A, aorta; Œ, œsophagus (the lung is divided transversely near its centre).
The ulcerations are localised in the mouth and pharynx, in the second half of the small intestine towards the ileum, and in Peyer’s patches.
Tuberculous lesions develop in the vaginal sheath of the male genital organs exactly in the same way as in an ordinary closed serous cavity; tubercles may also develop on the surface or in the substance of the testicle. They become aggregated, undergo softening, spread towards the interior, and may break down, thus forming abscesses. In the female genital passages the disease invades the thickness of the walls, but shows a marked tendency to ulceration, as in the intestine or trachea.
In the udder tuberculosis is generally diffuse, shows a tendency to hypertrophy and the free formation of fibrous or sclerous tissue; only tubercles in the glandular layer of the acini become ulcerated. In time the whole of the secreting structure undergoes diffuse tuberculous suppuration, fibro-caseous masses form in the depths of the tissue and may soften, producing deep-seated tuberculous “cold abscesses.” The mammary lymphatic glands are affected in the same way as other lymphatic glands.
In the joints tubercles appear either on the synovial membrane or in the thickness of the bony epiphyses, very often at both points simultaneously. The synovial membrane is covered with vegetations and villous growths, the ends of the bones are attacked by a destructive ostitis, tubercles or tuberculous centres form in the thickness of the spongy tissue, the articular cartilages are destroyed, the ends of the bones become deformed, and in the last stages fungoid arthritis in various forms may be produced.
In bones the tubercles originate in the depths of the spongy tissue. They produce destructive hypertrophic ostitis, in which the bony tissue is replaced by tuberculous centres or masses divided by fibrous partitions. On section, these lesions exhibit the same yellowish caseated or calcified appearance as the lesions of other affected organs. The compact layer may sometimes be perforated at several points before being destroyed.
In tuberculosis of the brain the primary lesions develop at the expense of the serous layers of the arachnoid and on the pia mater, towards the base of the brain and the fissure of Sylvius, or at the expense of the small vessels which penetrate the depths of the nerve substance itself. Some tubercles remain isolated, become confluent or are collected in masses of different sizes, and provoke symptoms which vary with the locality attacked.