The leprous and tuberculous affections of the lymph glands are macroscopically so very different, that it is impossible to confuse them, and the microscopical differences are still more evident. Both fresh and hardened preparations were always examined. And since the lymph glands are always affected with leprosy, if the organs which drain into them are affected, even if this affection is very slightly developed, we conclude from the fact that we have never seen a leprous bronchial or mesenteric gland, that there is no leprous affection of the lungs or of the intestine, and later examination of certain special preparations have only confirmed us in this view. But more of this later, and we will first treat of the differences between tuberculosis and leprosy.
In organs affected with tubercle one always finds, as is well known, giant cells and caseous degeneration; in the many, we can truthfully say, thousands of preparations of leprous affections, which we have had under the microscope, we have never seen either a typical giant cell with marginal nuclei or caseous degeneration. There are indeed multinuclear cells in the lepromata, but never giant cells like those of tubercle.
What may be the reason for this striking difference in the action of the very similar bacilli of tubercle and leprosy, we have no idea; we simply state the fact and assert that, if one finds giant cells, he is dealing with tuberculosis and not with leprosy. This alone would be sufficient to cause us to separate the two neoplasms, but there are many other distinctions. Tubercle is avascular; the leproma is rich in vessels; tubercle undergoes caseous degeneration, the leproma never. Anatomically therefore, we are justified in maintaining a sharp distinction between the two diseases.
So far as concerns the resemblance between the tubercle and lepra bacilli, we must not omit to mention that one almost always finds among tubercle bacilli some which are pretty long and somewhat bent; this is never the case among lepra bacilli. Baumgarten has indicated as a distinction between them, the fact that the latter is more easily stained; according to our experience this distinction can scarcely be regarded as sufficient. But the distribution of the bacilli in the tuberculous and leprous tissue is usually so very different, the tubercle bacilli being usually arranged singly, the lepra bacilli always in large quantities in masses and clumps, that a confusion of the two diseases anatomically can only be possible in exceptional cases. Danielssen has repeatedly stated in his triennial report of the Lungegaards Hospital that tuberculosis and leprosy are such nearly allied diseases that the one (leprosy) may pass into the other (tuberculosis) by a modification of the bacilli, and that thus the frequent combination of the two diseases is to be explained. This view we cannot, in view of the above demonstration, support. If an organ is attacked at the same time by tuberculosis and leprosy, one can anatomically very readily separate the two diseases. We would rather seek the explanation of the frequent combination of the two diseases in our institutions in the great over-crowding and consequently insanitary conditions to which they were formerly subjected. Tuberculosis once introduced, we find a ready explanation in the bad habits of the patients in regard to expectoration, why it was difficult or impossible to root it out. In later years, when the institutions are no longer full and the sanitary conditions consequently much improved, tuberculosis has much decreased. Whether tuberculosis was as frequent a combination in the country as in our institutions we do not know. The duration of life of patients in the country is about a year longer than in our institutions, and possibly this depends on the absence of tuberculosis.
Doutrelepont has recently described in the transactions of the German Dermatological Society, On the Pathology and Therapeutics of Leprosy, a lung affection, probably developed by tuberculine treatment, which he diagnosed from the examination of the sputum. But the patient had a leprous affection of the larynx, and his account by no means excludes the possibility that the bacilli in the sputum came from a ruptured nodule in the larynx, possibly softened by the tuberculine treatment. We cannot, therefore, recognise this observation as infallible evidence of the presence of a leprous lung affection, any more than that case of leprosy of the lungs described by Bonome in Virchow’s Archiv, Bd. C. That author himself draws attention to the great resemblance of the affection to tuberculosis, and as it is quite evident from his description of the bronchial lymphatic glands that they were not leprous, and he notes the presence of giant cells in the pathological products, we cannot doubt that it was really a case of tuberculosis.
In the same case there was found an affection of the spinal cord, from which Bordoni-Uffreduzzi cultivated on glycerine agar an organism which he recognised as the lepra bacillus. Here we may remark in the first place that we have never seen a leprous affection of the spinal cord, and have never found bacilli in it. We must indeed admit that we have only examined the spinal cord in a few cases, because there appeared to be no indication for such an examination, since clinical symptoms do not point to an affection of that organ, and as in the profusely nodular cases, affections easily recognised appear everywhere, except in the liver and spleen, it was to be expected that an affection of the spinal cord would have been recognisable. In necrotic bones, which we have often examined, nothing leprous is found. This necrosis is therefore no specific leprous affection, but a secondary one. Secondly, we must remark that in spite of many attempts we have never succeeded in cultivating lepra bacilli on glycerine agar. We therefore believe that Bordoni-Uffreduzzi has cultivated tubercle bacilli instead of lepra bacilli. The only thing which speaks for the leprous nature of the lung affection and the cultivated bacilli, is the circumstance that the author did not succeed in inoculating guinea pigs and rabbits with tuberculosis. But, according to all investigations on tuberculosis, it appears to us not incredible that the tubercle bacilli may, under circumstances, become so weakened that they are no longer pathogenic.
Arning has described a miliary leprosy, and found in the products of this disease giant cells, and also leprous ulcers in the intestines. Dr. Arning has kindly sent us some preparations of this miliary leprosy, in which we find evidence everywhere that the case is one of tuberculosis, both because giant cells are found everywhere, and the bacilli are only present singly, and scattered. They are never present in the excessive numbers, and have not the arrangement, which they usually have in leprous products. In connection with the presence of giant cells in leprous products, we may note that we have received from two foreign colleagues preparations in which they believed giant cells to be present. But we have found, on careful examination of the preparations, that they were cross and oblique sections of blood vessels, which with their endothelial nuclei gave the impression of giant cells. Without the use of a homogeneous immersion lens it was not possible to make a definite distinction.
According to our observation there exists a sharp anatomical distinction between leprosy and tuberculosis, and there is no such thing as leprosy of the lungs and intestines, the bones and the kidneys. In order to establish a differential diagnosis in doubtful cases, we recommend in the case of the lungs and the intestines a thorough examination of the bronchial and mesenteric glands. We ourselves have never sought in vain, in cases of these affections, for tuberculous or caseous degeneration in the glands, and we have seen in no single case anything resembling leprous affection of the glands.
So far as concerns the central nervous system, Danielssen noted that he had several times seen acute hydrocephalus in leprosy. We once saw severe cerebral symptoms with maniacal attacks. The patient, who was taken into a lunatic asylum, left this later, cured. Other indications of an affection of the central nervous system in leprosy are unknown to us. Anatomically, we have not been able to recognise in the nervous system any traces of leprosy. In connection with this, we may note that we have several times seen pain and swelling of the knee joints during eruptions, which at their conclusion disappear. In these cases there is nothing to be made out anatomically. When we reflect that, as indicated in describing the eruptions, the bacilli and (or) their toxines most probably circulate for some time in the blood, it is remarkable that the organs above referred to are not affected by leprosy. We can give no reason for this; connective tissue, which is especially liable to be affected, is present everywhere.