Definition. Relation to leukæmia. Causes. Mainly accessory. State of
lymph glands, spleen, liver, bone marrow, intestine, tonsils, thymus,
kidneys, liver, lungs, bronchial mucosa, pleura, pericardium, nervous
system. Symptoms, as in leukæmia, with adenoid hyperplasia, but little
leucocythemia. Relation to glanders. Uric acid, low density, no
hippuric acid. Tuberculin and mallein tests. Treatment, as in
leukæmia. Excision in cases not constitutional. Phosphorus, phosphide
of zinc.
_Definition._ Hypertrophy of the lymphatic glands with little or no
leucocytosis. There may further be lymphoid growths in the liver,
spleen, bone marrow and other organs.
The visceral lesions in lymphadenoma do not differ in character from
those of leukæmia, and as it does often apparently merge into that
disease by the characteristic changes in the blood, it is denied by many
that it constitutes a separate pathological entity. In his admirable
monograph on leucæmia in the lower animals Nocard affirms their
identity. The main excuse for keeping up an alleged distinction, is the
frequent absence of leucocytosis, and this often supervenes after the
lymphadenoma has existed for some time.
_Causes._ As in leucæmia, no definite cause can be found in the majority
of cases. An accessory cause can sometimes be observed where a local
irritation gives rise to swelling of the adjacent lymphatic glands and
this goes on to distinct lymphadenoma.
=Lesions in the Lymph Glands.= The hyperplasia may affect but a single
group of glands, more commonly a number of groups, and often nearly all.
In one case only of leukæmia in the lower animals, a dog, has Nocard
failed to find the lymph glands affected. In the horse he has found the
sublumbar glands alone weighing 14.5 kilogrammes, 11 k. and 8 k. They
compressed the posterior aorta and vena cava and had caused extensive
ascites.
The enlarged glands are white, gray or in case of rapid growth veined or
pointed with red; they may be soft or firm according as the hyperplasia
has operated most on the trabeculæ or the cells; they are homogeneous
throughout. The scraping of the cut surface gives a more or less thick
milky juice containing a great number of nucleated or double nucleated
lymphocytes, free nuclei and granules which stain strongly.
Hardened sections show an enormous development of the follicles at the
expense of the medullary walls, and double nucleated white globules
packed in a rich reticulum of adenoid tissue, whilst the bloodvessels in
the connective tissue are crowded with white cells, and there are slight
ruptures, old or recent.
=Lesions of the Spleen.= These are nearly always present. Leisering
found a horse’s spleen over three feet long and 28 lbs. weight, and
Nocard one of 13 lbs. Bollinger found a pig’s spleen 3½ lbs.
Siedamgrotzky found dog’s spleens over 2 lbs. The consistency is usually
firm (sometimes soft in dog). Capsule thickened and white, cut surface
dry, reddish brown, granular, Malpighian bodies enlarged like a pea,
hazel nut or walnut, with contents as in the lymph follicles. The
capillaries are enlarged and crowded with white cells.
=Lesions in the Liver.= The liver is enlarged in one-half of the cases
of leukæmia in the lower animals. It has been found to weigh 20 lbs. in
the horse, and 4 lbs. in the dog. It is of a grayish brown, or yellowish
brown hue, or light red spotted with yellow, or mapped out by
anastomosing grayish white lines. There may be enlargement of the acini,
or the formation of little nodes of adenoid tissue, or most commonly in
the lower animals, there is an adenoid thickening of the bands of
connective tissue extending in from the capsule. These are filled with
white cells which stain deeply with carmine. There may also be slight
extravasations of blood and infarcts.
_Lesions in the Bone Marrow._ These noticed in the pig by Fürstenberg,
and in dogs by Siedamgrotzky, consist in increased vascularity, great
cell hyperplasia, and formation of adenoid tissue as described under
leukæmia.
=Lesions of the Intestine.= These commence in the agminated or solitary
glands, which become enlarged, causing thickening of the mucous
membrane, and later grow out into more or less rounded masses of
lymph—adenoid tissue up to an inch in thickness. They are quite subject
to ulcerations.
=Lesions of the Tonsils.= Bollinger, Nocard and Siedamgrotzky found
these enlarged in dogs in connection with adenoma of the spleen. They
were soft, friable, grayish, and consisted of a very delicate and
fragile adenoid tissue.
In one case Siedamgrotzky found adenoid hypertrophy of the thymus in a
cow, and adenoma of the kidneys similar to that of the liver has been
noticed.
Similar adenoid hyperplasia has been found in the lungs, the bronchial
mucous membrane, the pleura, the mediastinal and bronchial glands, and
the pericardium. In man this has invaded the nerve centres, and it seems
that at any point where there is a lymph gland or a lymph plexus this
adenoid hyperplasia may localize itself.
_Symptoms._ The general symptoms of failing health are as described in
leukæmia. The particular symptoms of this disease consist in the
recognition of the adenoid hyperplasia in the absence of a marked
leucocytosis. The submaxillary glands are usually the first attacked,
and the disease may, in the horse, be confounded with glanders. There
is, however, no pituitary discharge nor ulcer, the glands are enlarged
symmetrically on the two sides, and a careful search will usually
discover other groups with similar symmetrical enlargement. The
parotidean, the pharyngeal, the prepectoral, the prescapular, the
axillary, the popliteal, the prefemoral, the post and premammary, and
the inguinal should be critically examined. The enlarged mesenteric
glands may be reached and detected by the hand engaged in the rectum, or
in the small animals by external palpation, as may also the enlarged
spleen or liver.
The adenoid hyperplasia in the chest offers very obscure and uncertain
symptoms. The enlarged bronchial and mediastinal glands may seriously
interfere with the functions of the vagus nerve, causing, in cattle,
disturbed digestion and rumination and tympanies, in horses stertorous
breathing, and in the carnivora and omnivora a tendency to vomiting. In
animals generally the pressure on the cardiac nerves leads to great
irritability of the heart, and violent action under any exertion. The
prominent dyspnœa in the advanced stages may be explained by these
thoracic hyperplasiæ.
Nocard claims that the urine furnishes most important indications in its
low specific gravity (horse 1010), its constant acidity, and in the
almost entire absence in that of the horse of hippuric acid. When there
is any suspicion of tuberculosis or glanders, the tuberculin or mallein
test will decide.
_Treatment_ is essentially the same as in leukæmia, and equally
unsatisfactory. Arsenic has in the main given the best results. In the
very earliest stages when the granular hyperplasia is confined to one
group, excision is advisable. This should be avoided in all cases in
which the constitutional symptoms have developed. Phosphorus and
phosphide of zinc have seemed beneficial in certain hands. Injections
into the glands have so far proved useless.