FIG. 6.-Mouse. Spindle cell sarcoma, consisting of spindle cells with delicate interstitial collagenous fibrils and thin-walled capillaries, adjoining the kidney cortex (to left). x 1 500 SPINDLE-CELL SARCOMA OF THE KIDNEY REGION. A large intra-abdominal growth surrounding the right kidney was found by Professor Jensen of Copenhagen in an English mouse sent to him by Dr. Bashford two and a half years ago. The growth surrounds the kidney without infiltrating it, and consists of delicate spindle-cells with a varying amount of intercellular collagenous fibrils, and a very abundant supply of thin-walled capillaries (fig. 6). Transplantation was performed by us into 374 normal mice without success. Professor Jensen also transplanted into normal animals with negative results. ADENOMA OF LUNG. The tumours which are regarded as adenomata of the lung, were first described by Livingood in 1896. Borrel and Haaland also found these growths in a considerable number (5) of the mice with spontaneous mammary carcinoma described in the latter's paper of 1905. Recently (1907) Tyzzer has given an exhaustive account of twelve cases found in old mice examined by him. Tyzzer notes that half of the animals presented a growth in other parts of the body, while in the remainder the lung tumour was the only one present. In all these cases the structure of the growths is very uniform. The cells of the growth are usually large, cubical or columnar, and arranged upon the elastic framework of the lung alveoli in a single layer. In the smaller nodules they appear to pass insensibly into the epithelium of the air-alveoli or alveolar passages. Haaland has figured the cells actually loaded with pigment like the familiar catarrhal cells of the lung. In older, i. e. large nodules, pressure phenomena occur at the surface, and the tumours are more sharply separated off from the surrounding lung tissue. Tyzzer has described invasion of a small bronchus by a papillomatous ingrowth of tumour. All authors have noted the absence of mitotic figures in the cells of these growths. Tyzzer, however, found mitoses in one of his cases and refers to the frequency of indications of direct nuclear division in the form of cells with two nuclei, an observation we can confirm. In one case of our material mitotic division of a nucleus was seen, but it is in any case extremely rare. The cases in our material have with two exceptions been found in animals with spontaneous mammary tumours. We are nevertheless inclined to agree with Tyzzer that the association is accidental and due to the greater care with which we have examined the lungs of mice suffering from spontaneous carcinoma of other regions. SEBACEOUS ADENOMA. In three aged female mice bearing spontaneous mammary tumours 71, 74, 77-78)*, small white glistening nodules were found on the skin. In mouse in mouse 71 77-78 74 0 the nodule was situated in the left groin, in mouse 0 two were present, one in the right axilla and one on the upper lip, and the nodule was situated behind the right ear. Microscopical examination showed that all had the same structure, that namely of an adenoma of the sebaceous follicles (fig. 7). Those which have been observed grew very slowly, and although that from mouse was inoculated both by subcutaneous implantation and by scarification of epilated skin and rubbing with a piece of the growth, no reproduction of the lesion could be obtained. The interest of the condition lies in the fact that Tyzzer has been able to transplant successfully a similar, but much larger growth. 77-78 0 MALIGNANT LYMPHOMA OR LYMPHADENOMA. This peculiar condition was first described by Haaland (1905) from Borrel's laboratory as a generalised hyperplasia of the lymphoid tissue throughout the body. Five of his six cases occurred during two years in mice kept in the same cage. The second case occurred during the life-time of the first. Extended attemps at experimental transmission gave a negative result. Tyzzer (1907) describes a case in which a single gland (right inguinal) was enlarged. Transplantation was attempted without success. Haaland also records a similar result. Four cases of this condition have occurred in our material. In two practically universal dissemination had occurred as in Haaland's cases. In the other two the growths were more localised. In the first of our generalised cases ()the main enlargement was in the glands in the neck, those over the shoulder and in the axillæ. The structure is as described by Haaland and Tyzzer, a lymphoid tissue approaching the type of the germinal centres of lymph gland. In the second of these (10) all the lymph glands in the body appeared to be enlarged, the liver and spleen were likewise affected and the chest was full of growth. Of our localised cases, one (11) presented a nodule nearly cases * For explanation of nomenclature of spontaneous tumours, see p. 102. Microphoto by R. Muir. FIG. 7.-Mouse. Sebaceous adenoma: Case in mouse with spontaneous mammary The epithelial masses consist of cells with the characteristic carcinoma 77-78 appearance of those in sebaceous follicles. 33 FIG. 8.-Mouse. Lymphadenoma: High power figure of thoracic growth replacing right lung in spontaneous mouse 19 500 . |