Actinomycosis. Ray Fungus in Man. (Gaylord.)
ACTINOMYCOSIS.
This also is a subacute but always destructive infection by a specific microörganism, though not a bacterium. Known always as actinomycosis in man, the disease, which is most common in cattle, is called lumpy jaw or swelled head, and years ago was usually regarded as cancer or as a malignant affection.
Many museum specimens labelled as cancer of the tongue, jaw, etc., have been shown to be instances of actinomycosis of these parts. It is occasionally met with in man, so that there are at least four hundred cases on record in this country and in Europe. The organism was recognized a half-century ago by Langenbeck and Lebert, but was not scientifically described until many years later. The names of Bollinger, Israel, and Ponfick will always be connected with these researches.
The organism belongs among the ray fungi, is known as the actinomycis, and occupies an uncertain place in classification. It is large enough, when entire, to be perceived by the naked eye, has ordinarily a yellowish tint, a tallowy consistence, and may be seen under the microscope to consist of a cluster of branching prolongations, club-shaped at the end, radiating from a common centre. They give it a sunflower appearance. It is stained with difficulty, the best stain being a combination of picrocarmine and an aniline dye. In tissue sections the Gram stain is the best. It is cultivated with difficulty, but can be grown upon solid media and may be inoculated. (See [Plate V].)
As met with in tissue or in pus these fungi constitute small granulations, giving usually a gritty sensation to the finger, which is due to the presence of calcium salts. The recognition of this calcareous material is of importance, since it may enable a diagnosis to be made offhand, in a case which otherwise might puzzle one.
The disease is very common among cattle in certain regions, and causes the condemnation of many animals in every large stockyard establishment where inspection is careful and scientific. It occurs oftener in young than in old animals, and most frequently in those which come from valley regions and marshes. In animals infection occurs almost invariably through the mouth, which is easily explained by the fact that, in grazing, the lips, tongue, and gums are likely to be irritated and infected at any time from soil containing these fungi along with growing grain. The path of infection is usually by the mouth, while accident seems to determine whether the infection shall manifest itself mainly in the intestinal canal or the respiratory tract. In animals there is less tendency to suppuration than in man, the infection in man being usually a mixed one. The name lumpy jaw, so generally given to the affection, is indicative of the most conspicuous lesion in cattle, for the organism, having once invaded the gum, for instance, passes quickly to the bone, or, having involved the tongue, is not slow to infect the lymphatics of that region. In consequence we have tumors, often of inordinate size, which may involve the bones or the soft parts and cause great disfigurement, along with necrosis, leading eventually to the death of the animal. These tumors are essentially granulation tumors due to the presence of a specific irritant—the actinomycis—which acts here as do the tubercle bacillus, the lepra bacillus, etc., in other infectious granulomata.
In man the disease is generally accompanied by abscess formation, the pus containing the distinctive yellow gritty particles which are found in no other disease. The strong resemblance between the lymphoid cells of this form of granuloma and the embryonal cells of sarcoma has permitted the perpetuation of confusion between these two neoplasms.
Fig. 19
