MALIGNANT TUMOURS IN DOGS - Cancer ResearchMALIGNANT TUMOURS IN DOGS 209 which closely parallel those of some cases of intra-abdominal carcinoma in man (see Willis, 1934, pp. 387-88)

MALIGNANT TUMOURS IN DOGS

A DESCRIPTION OF NINE CASES

H. B. RUDDUCK, B.V.Sc., M.B., B.S., AND R. A. WILLIS, M.D., DSc., M.R.C.P.

(From the Baker Medical Research Institute, Alfred Hospital; and the University Department of Pathology, Melbourne, Victoria, Australia)

That malignant tumours are common in elderly dogs is well known (Mc- Fadyean, 1899; Sticker, 1902; Murray, 1908; Feldman, 1932, pp. 66-68), and our object in describing the following specimens is not merely to add to the list. We have had opportunity recently of examining over 30 neoplasms from dogs, and of performing complete post-mortem examinations on a num-

FIG. 1. CASE I: PHARYNX AND LARYNX VIEWED FROM DORSAL ASPECT AFTER OPENING PHARYNX ALONG MID-DORSAL LINE, TO SHOW CANCEROUS RIGHT TONSIL, DENOTED BY ARROW. X 36

ber of the animals, and have selected 9 cases as worthy of record either because of the rarity of the tumours or because they exhibit some noteworthy parallel to or contrast with their human counterparts. Histologic sections of all relevant lesions were prepared by the paraffin method from formalin-fixed material, and were stained by haemalum and eosin and by Heidenhain’s iron- haematoxylin and Van Gieson’s stain.

CASE I: Squamozu-cel l Carcinoma of the Tonsil with Metastases in Lymph Nodes and Lungs: For some months a male Irish terrier had been losing weight and strength and suffering from impaired voice. Large masses of growth developed in the neck, and the animal was killed.

At autopsy large lobulated masses of hard white growth were found in each side of the neck, that on the right side being 10 cm. in main diameter and 120 gm. in weight, and that

205

206 H. B. RUDDUCK AND R. A. WILLIS

on the left measuring 6 cm. in diameter and weighing 40 gm. At first these growths were thought to have arisen from the thyroids, but dissection revealed that the latter were in- tact and that the growths consisted of many fused cancerous lymph nodes. It was then ob- served that the right tonsil was slightly enlarged, white, and firm (Fig. 1). The lungs contained many metastatic nodules up to 1 cm. in diameter, and some small deposits of growth were present in the bronchial lymph nodes. No tumours were found in any other viscera. The bones and intracranial contents were not examined.

Histology: The growth presented a similar structure in all situations, that of a rapidly growing epidermoid carcinoma with irregular cancerous clumps separated by a moderate amount of connective-tissue stroma. The central parts of some of the clumps showed patchy keratinisation, while others showed degenerative changes. Mitotic figures were plentiful in the tumour cells.

FIG. 2. CASE 11: SECTION OF THYROID, SHOWING CARCINOMA CLUMPS IN INTERSTITIAL LYMPHATICS. X 263

CASE 11: Squamous-cell Carcinoma of the Tonsil with Metastases in Lymph Nodes and Lungs: An adult Australian terrier was noticed to be suffering from dyspnoea, general weak- ness, and tumours in the neck, and was therefore killed.

Huge cancerous masses lay in each side of the neck, the larger on the left. The left tonsil, though normal in size, was firmer and paler than its fellow. Both thyroid glands were slightly enlarged and firmer than normal, showing areas of solid white tissue amid the vesicular thyroid tissue. The lungs contained multiple white metastatic nodules up to 1 cm. in diameter. Until microscopical sections were prepared, the primary origin of the growth was uncertain but was believed to be in the left thyroid gland.

Histology: The left tonsil was clearly the source of the tumour, which in all situations appeared as an anaplastic, rapidly growing, large-cell carcinoma. The cells were arranged in large irregular clumps with much central degeneration and occasional patches of cornifica- tion. Both thyroid glands showed widespread infiltration by the growth, apparently for the most part by way of the lymphatic channels (Fig. 2 ) . In the lungs the extension of the growths was partly intra-alveolar and partly by the perivascular and peribronchial lymphatics.

Comment on Cases I and 11: Carcinoma of the tonsil is apparently rare in dogs; it is not specifically mentioned by either Sticker or Feldman. Feldman, however, mentions one case of carcinoma of the pharynx (p. 303) , and refers

The post-mortem findings were very similar to those of the previous case.

Mitotic figures were plentiful.

MALIGNANT TUMOURS I N DOGS 207

also to a statement of Hobday that pharyngeal carcinoma frequently occurs in dogs. Our two cases were strikingly alike in both their gross morbid anatomy and their histologic structure, and closely resembled many of the carcinomas of this region in human beings. Particularly notable in both instances is the development of huge cervical metastases from small inconspicuous primary growths in the tonsil, a feature which is frequent in human tonsillar cancer also, and has caused many diagnostic errors (Willis, 1934, p. 180).

CASE 111: Adenocarcinoma of the Cardiac Orifice of the Stomach with Metastases in Mediastinal Lymph Nodes: For four months a collie, eight years old, had suffered from difficulty in swallowing and immediate regurgitation of all solid food.

FIGS. 3 AND 4. C A S E 111: CARCIPI’OMA OF THE C A R D I A

Fig. 3 (left) is a view of the interior of the lower part of the oesophagus and cardia ( X %), The bracket A shows

Fig. 4 (right) is a section of the oesophageal wall near the cardia, show- showing nodular growth and great thickening of walls around the orifice. the extent of the growth. ing adenocarcinomatous clumps amid voluntary muscle fibres ( X 265).

At autopsy there was found at the junction of the oesophagus and stomach an irregular cauliflower-like growth projecting into the lumen to a height of 1 cm. (Fig. 3). The main projecting mass involved about one-half the circumference of the orifice, the other half of which showed irregular nodularity and smaller papillary outgrowths. The adjacent walls of the oesophagus and stomach were rigid and thick, attaining a maximum thickness of 1.5 cm. In the pcri-oesophageal tissues at a level 10 cm. cranial to the cardia a small indurated area including an anthracotic lymph node was found; a second small, hard nodule was present 18 cm. above the cardia. The walls of the oesophagus and the surrounding tissues intervening between these nodules and the growth at the cardia appeared normal. No secondary growths were found in any other viscera or lymph nodes.

Histology: The tumour was an adenocarcinoma consisting of irregular acini lined by columnar or cuboidal cells (Fig. 4) with, however, many areas of diffusely invading columns of spheroidal cells devoid of any glandular orientation. There was widespread interstitial infiltration of the muscle coats of both the oesophagus and stomach near the cardia. The hard nodules in the upper peri-oesophageal tissues consisted of small lymph nodes containing and surrounded by infiltrating carcinoma, with prominent extension via the perineural lymphatics.

208 H. B. RUDDUCK A N D H. A. WILLIS

Comment: The stomach is one of the rarest sites of cancer in dogs (Feld- man, p. 308), a feature of canine pathology which is in striking contrast to its human counterpart. A noteworthy point in the present case was the long dis- tance intervening between the primary growth and its lymphatic metastases, one of which was high up in the thorax about 7 inches from the cardia.

CASE IV: Adenocarcinoma of the Pancreas with Metastases in Peritoneum and Lymph Nodes: An adult male collie, the previous history of which was unknown, was destroyed because of general debility and abdominal swelling.

At autopsy all parts of the peritoneum showed extensively disseminated firm white growths, which were particularly massive around the pancreas, in the omentum and the mesentery, and around the umbilicus. Some blood-stained ascitic effusion was present in the abdominal cavity. By extension through the diaphragm the tumour had reached the

F I G . 5 . CASE Iv: SECTION OF ABDOMINAL WALL NEAR TIIE UMBILICUS, SIIOWINC CANCEROUS PERMEATION OF THE LYMPHATICS ON THE SURFACE OP THE APONEUROSIS. X 55

basal parietal pleura, which showed small plaques of growth. Tumour deposits were present in some of the retroperitoneal lymph nodes. There was no primary growth in the stomach, intestines, gallbladder, liver, or pelvic organs, the pancreas being the only epithelial viscus affected.

Histology: Most of the growth was anaplastic, consisting of diffusely arranged spheroidal and spindle-shaped cells with many mitotic figures. In places, however, especially where the growth was invading the abdominal wall around the umbilicus, well defined epithelial clumps with occasional acinar cavities were seen, some of which lay within permeated lymphatics (Fig. 5 ) .

Comment: Carcinoma of the dog’s pancreas is evidently an infrequent tumour; of Sticker’s 766 carcinomas in dogs, only 2 were primarily pancreatic, and Feldman (p. 309) refers to only 2 other reports, those of Kitt and Borrel. In the present instance, the widespread peritoneal carcinomatosis and metastasis to lymph nodes without dissemination by the blood stream, and the invasion of the abdominal wall via lymphatics from the umbilicus, are features


which closely parallel those of some cases of intra-abdominal carcinoma in man (see Willis, 1934, pp. 387-88).

CASE V: Adenocarcinoma of the Prostate with hletastases k Lymph Nodes, Lungs, and One Kidney: An Alsatian nine years old developed pain and difficulty on defaecation, ano- rexia, and vomiting. Rectal examination revealed narrowing of the lower part of the rectum caused by great enlargement of the prostate ventrally and a mass of enlarged pelvic lymph nodes dorsally.

At autopsy the prostate was found to be much enlarged, 6.5 X 6 X 5 cm. in dimensions, irregularly lobulated, and largely replaced by firm white growth. The pelvic and lumbar lymph nodes were replaced by growth and greatly enlarged, the largest being over 4 cm. in diameter. The lungs were studded by many spherical white metastatic tumours up to 2 cm. in diameter; and the mediastinal lymph nodes also contained small tumour deposits. I n one kidney were three small rounded metastases, all in the cortex; the other kidney was

The animal was killed.

FIG. 6 . CASE V: SECTION OF PROSTATIC GROWTH. X 80

normal. No tumours were found in the heart, spleen, liver, gastro-intestinal tract, peritoneum, nor in the vertebrae, sacrum, pelvis or femora, all of which were first studied in skiagrams and subsequently sectioned. The skull and its contents were not examined.

Histology: In all situations the tumour was a cellular, rapidly growing adenocarcinoma with many mitotic figures. The better differentiated parts of the growths contained a largc number of gland-like acini lined by cuboidal or low columnar cells (Fig. 6 ) , and closely resembled in structure the small-acinar adenocarcinomas of the human prostate. In other parts the growths were more anaplastic, and glandular architecture was scarcely recognizable.

Comment: The prostate is an infrequent site of carcinoma in animals. Of 766 cases of canine carcinoma reviewed by Sticker (1902), only 10 involved the prostate; and Feldman (p. 309) refers to only one recorded case, that of Horne, which, like our case, was an adenocarcinoma with metastases in the lungs. Notable also in our case is the close resemblance to human prostatic carcinoma seen in many parts of the growth. The small-acinar carcinoma of the human prostate is often a fairly distinctive type of growth, the acini of which may recognizably resemble those of the normal prostate. The present tumour exhibits a similar structure.

210 H. B. RUDDUCK A N D R. A. WILLIS

FIG. 7. CASE VI: SWEAT-GLAND CARCINOMA: GENERAL VIEW OF TIIE MICROSCOPIC STRUCTURE Note small epithelial clumps with capsules of fibrous tissue, resembling sweat glands. X 100.

FIGS. 8 AND 9. CASE VI: SWEAT-GLAND CARCINOMA Fig. 8 (left) is a section at the periphery of the growth, showing isolated epithelial clumps like

solid sweat glands ( X 100). Fig. 9 (right) is a higher-power view of a sweat-gland-like clump, showing also continuity of the masses of growth with ducts of sweat glands, X X ( X 2 6 5 ) .

CASE VI: Sweat-gland Carcinoma of the Skin: A firm, smoothly lobulated, well defined growth 5 cm. in diameter was excised from the skin of an Australian terrier. T h e growth, which was uniformly white on section, lay mostly in the subcutaneous tissue but was adherent to the overlying thinned skin.

Histology: The tumour consisted of well-defined rounded clumps or elongated tortuous columns of closely packed small polyhedral epithelial cells with relatively large nuclei and

Contrary to a widely prevalent impression, sweat glands are present in the skin of the dog, and dogs can and do sweat.


FIGS. 10 AND 11 . CASE VII: CYSTIC AND PAPILLARY CARCINOMA OF THE BREAST Fig. 10 (left) shows cysts and intracystic papillary growth.

X 80. Fig. 11 (right) is another view of

a papillary growth in a cyst.

ill defined cell outlines (Figs. 7-9). The epithelial clumps and columns were closely set in a moderate amount of fibrous and vascular stroma, and were of a fairly uniform width, between 60 and 120 P, though larger irregular epithelial masses were present in places. Many of the clumps were encircled by a well defined zone of condensed hyaline or cellular connective tissue. Most of the clumps appeared to be solid, but here and there a distinct small central lumen could be found. This feature, as well as the general size and arrangement of the epithelial tissue, made it probable that the tumour was a sweat-gland adenocarcinoma, a conclusion further confirmed by the finding of tumour columns in continuity with residual sweat glands and ducts (Fig. 9) .

Comment: From the human cutaneous glands and hair follicles there arises a group of epithelial tumours of relatively slow growth and low malignancy, non-cornifying in type, closely allied to one another structurally, and allied to or including rodent carcinomas. Of any individual tumour in this class it is often impossible to assert the precise origin. Feldman (pp. 325-329) de- scribes and figures several such tumours in animals, and the present example falls into the same group, its structure strongly suggesting an origin from sweat glands.

CASE VII: Cystic and Papillary Carcinoma of the Breast: A black Cocker Spaniel bitch had suffered gradual enlargement of one of the breasts for two years, with more rapid growth recently. The tuniour was a smoothly lobulated, rounded cystic mass 14 cm. in diameter. I t was excised with ease, and the dog was discharged in good health three weeks later. On section the tumour was found to consist of several large and many small cavities, some with a smooth lining, others with ragged white masses of intracystic growth. The contents of the cysts were partly clear, partly blood-stained fluid.

Histology: The tissues intervening between the cystic spaces showed many mammary lobules and ducts which presented the usual changes of cystic hyperplasia as seen in the human breast. All stages of transition between these and the large cysts could be traced. The white masses of intracystic tissue consisted of finely villous and branching papillary growth clothed by small cubical epithelial cells and with a markedly cellular connective- tissue stroma (Figs. 10-12). Patches of calcification were present in parts of this growth.

Mitotic figures were fairly numerous.


In the walls of some of the cysts the epithelium had given rise to areas of spheroidal-cell carcinoma which extended out into the surrounding tissues in solid masses (Fig. 1 2 ) .

Comment: Mammary carcinoma is one of the most frequent tumours of dogs, accounting, for example, for 341 of the 766 cases of canine cancer reviewed by Sticker. Many other examples are cited by Feldman (pp. 307-08). Our reasons for describing the present example are the unusually cystic char- acter of the growth, the structural evidence of its having developed on the basis of cystic hyperplasia (" chronic mastitis ") similar to that seen in women, and its general resemblance to the intracystic papillary types of growth of the human breast. Like these, also, the tumour was evidently of a low grade of malignancy.

FIG. 12. C A S E VII: MASS O F SPHEROIDAL-CELL CARCINOMA I N THE TISSUE AROUND A PAPILLOMATOUS CYST. X 80

CASE VIII : Mixed Adeiaocarcinomatoi4s and Ossifying Timtour o f the Thyroid with Ossifying Metastases in Lungs: A male sheep dog aged ten years suffered from large growths in the neck and difficulty of respiration, and was destroyed.

At autopsy the left thyroid glaiid was found to be replaced by a hard, irregular growth 8 cm. in main diameter and weighing 90 gm. (The weight of a single normal thyroid from a large dog such as an Alsatian is 3 to 5 gm.) The growth consisted partly of firm white tissue and partly of red and brown degenerated tissue, and scattered through it were many calcified or bony areas. A large vein which issued from the lower pole of the mass was occupied for a length of 3 cm. and distended to a diameter of 8 mm. by a partly free, partly adherent cylinder of white growth containing much bony-hard tissue. The ri@ thyroid gland was enlarged to a smooth ovoid mass 4 cm. long, weighing 8 gm., which on section showed recognizable thyroid tissue but with opaque white patches, brownish dis- coloured areas, and small cysts. The lungs contained a few scattered, well defined white or brownish metastases measuring up to 1 cm. in diameter. No metastases were found in any other viscera or in any lymph nodes. The cranial contents were not examined.

Histology: The left thyroid tumour contained two components intimately mixed with each other, ( a ) epithelial tissue of varying degrees of differentiation and ( b ) non-epithelial tissue including much osteoid tissue and bone (Fig. 13). The epithelial elements com- prised colloid-containing vesicles resembling those of normal thyroid, vesicles without col-

Fig. 13

Fig. 15

MALIGNANT TUMOURS I N DOGS 21 3

Fig. 14

Fig. 16

FIGS. 13-16. CASE VIII: THYROID TUMOR WITH OSSIFYING METASTASES IN LUNGS Fig. 13. Section of thyroid tumour, showing bony trabeculae mixed with epithelial vesicles.

Fig. 14. Section of growth in a vein, showing some small epithelial vesicles along with calcified

Fig. 15. Calcified bony masses in a metastasis in lung. Fig. 16. Section at periphery of a pulmonary metastasis, showing an intra-alveolar clump of

X 240.

x 70.

bony masses. X 240. X 240.

growth which already shows osteoid differentiation.

loid, smaller closely packed acini, solid epithelial clumps with no acinar cavities, and areas of diffuse growth difficult or impossible to distinguish from the spindle-cell non-epithelial tissue with which i t was mingled. Mitotic figures were plentiful in the less differentiated areas. The osteoid and bony tissue consisted of irregular trabeculae, partly uncalcified and partly calcified, associated in many places with undifferentiated spindle-cell growth, giving the picture of an abundantly ossifying osteogenic sarcoma. The cylinder of tumour which had invaded a large vein consisted of much ossifying tissue mingled with some epithelial


elements including a few glandular acini (Fig. 14). The right thyroid gland contained no bony tissue but consisted wholly of epithelial elements generally resembling in kind and varying degrees of differentiation those in the left thyroid tumour. The metastases in the lungs consisted partly of well differentiated osteoid tissue and bone and partly of diffuse spindle-cell and pleomorphic-cell growth with many mitotic figures (Figs. 15-1 7 ) . No indubitably epithelial elements could be found in any of five different metastases examined. At many parts of the margins of the growths the advance of the tumour was clearly by intra-alveolar spread, and inany of the marginal intra-alveolar masses of tumour already showed well marked osteoid differentiation (Fig. 16). Associated with the osteoid tissue in places were conspicuous giant cells, up to 60 P in diameter, with many central *nuclei.

Comment: Malignant tumours of the thyroid containing bone and carti- lage, though rare, evidently form a well defined group of neoplasms, which, as far as can be judged from the scanty records, are most frequent in dogs. Funkenstein (1903) reviewed the few previous reports of such tumours, two

FIG. 17. CASE VIII: SPINDLE-CELL AREA OF A METASTASIS IN THE LUNG

of which, that of Siedamgrotzky and the second case of Zahn, were in dogs, while Sticker (1902 j , in his extensive statistical survey of tumours in animals, mentioned two examples of bone-containing thyroid carcinoma in dogs (Nos. 11, E, 3, and 11, E, 4). Funkenstein described two bone-containing malignant tumours in man, which he regarded as osteochondrosarcomas arising in goitrous thyroids. The thyroid tissue which was present in the tumours he believed to be merely included residues of the goitrous tissue. Chavannez and Nadal (191 1 j , however, in their review of mixed tumours of the thyroid, concluded that the thyroid epithelium in these growths is in a state of pro- liferation which may even be typically cancerous, and that the malignancy of such a tumour is indeed " total," involving all its components. This view is confirmed by the findings in the present case, in which epithelial elements ac- companied the osteogenic tissue in the invasion of a large vein. That the non- epithelial component of the growth was, however, the more actively malignant

MALIGNANT TUMOURS IN DOGS 215

is shown by the fact that the metastases in the lungs contained this component alone without any epithelial elements, a feature seen also in the cases of Zahn, Pick (quoted by Funkenstein), and Funkenstein.

A tumour such as the one described raises the vexed question of the possi- bility that sarcomatous transformation may take place in the stroma of a carcinoma. One of us has already expressed strong doubts as to whether such a transformation ever occurs and has emphasized that anaplasia in carcinomatous epithelium is usually the explanation of the alleged ‘‘ sarcomatous ’’ appearances (Willis, 1934, p. 169). While this scepticism is certainly still justified regarding most of the reports of supposed “ sarcomatous ” transformation and of supposed “ carcinosarcomas,” the present specimen compels us to admit that mixed carcinomatous and sarcomatous tumours do occur. The osteogenic tissue cannot be explained merely as the result of metaplasia

FIG. 18. CASE IX: DIAGRAM OF A CROSS-SECTION O F THE HEART, SHOWING EXTENT OF GROWTH, X X

Hatched areas: muscle. Widely stippled area: epicardial fat. Closely stippled area: growth. A. Aorta. R.A. and R.V. Right auricle and ventricle. L.A. Left auricle.

in the stroma of a carcinoma, since in the pulmonary metastases it is divorced from the epithelium and is clearly behaving as an independent invasive ele- ment. This is particularly clear in Fig. 16, which shows the advancing margin of growth to consist of tissue of unmistakable osteoid structure. We are then forced to conclude that the left thyroid growth was a mixed adenocarcinoma and osteogenic sarcoma, which, following invasion of a large vein by the mixed growth, produced osteogenic sarcomatous metastases in the lungs. Whether the thyroid tumour was mixed in type from its onset, or became mixed as a consequence of sarcomatous change supervening in the stroma of a carcinoma, cannot of course be decided with certainty. We believe the former view to be the more probable, the growth possessing ab initio “ total ” malignancy as con- ceived by Chavannez and Nadal.

CASE IX : Spindle-cell Sarcoma (Possibly Rhabdomyosarcoma) of the Heart, with Metastases in Lungs and Diaphragm: For two weeks before its death a male Australian terrier about ten years old was noticed to be getting weak and ill and to be suffering from increasingly rapid respiration.

Careful examination post mortem disclosed no abnormalities in the mouth, pharynx, trachea, oesophagus, thyroid, stomach, intestines, liver, pancreas, spleen, kidneys, adrenals, bladder, prostate, testicles, lymph nodes, or skin. The lungs The brain was not examined.


contained many well defined, small, firm brown nodules measuring up to 1 cm. in diameter. In the heart was a brownish, friable tumour which replaced much of the lateral wall of the right atrium and the upper part of the wall of the right ventricle, showing ragged invasion of the cavity of the atrium, in which blood clot and growth were mingled. Externally the tumour formed a smooth, flat hemispherical projection covered by epicardium. The pulmonary artery and the left chambers of the heart were uninvolved. Serial transverse sections of the heart showed the extent of the tumour clearly (Fig. 18). A metastatic nodule 8 mm. in diameter lay in the muscular substance of the diaphragm.

Histology; The tumour was a highly cellular spindle-cell and pleomorphic-cell growth, the cells of which were arranged partly in ill defined interwoven bundles, partly in a fine irregular network, and partly diffusely. Where spindle-cell bundles were present (Fig. 19)

FIGS. 19 AND 20. CASE IX: SPINDLE-CELL SARCOMA OF HEART WITH METASTASES Fig. 19 (left) shows the spindle-cell growth in the heart ( X 265). Fig. 20 (right) is a reticular

area of growth in the diaphragmatic metastasis. Note pigment granules in the muscle fibres of the invaded diaphragm ( X 2 6 5 ) .

the cells were often very elongated and appeared to form in places an anastomosing network. Whether true anastomosis was really present, however, could not be made out with certainty; the appearances may have been due to the superimposition of cells crossing one another obliquely. Where a network arrangement was prominent, the cells were small, fusi- form or ovoid in shape, and formed an irregular fine-meshed lattice (Fig. 20). The tumour was very vascular in most parts, and haemorrhage and granular deposits of extravasated blood pigment were prominent features. In many parts the pigment granules were abundant in both the cells of the tumour and those of the invaded tissues (Fig. 20). The larger nodules in the lungs were particularly vascular and haemorrhagic. The appearance of the spindle-cell parts of the tumour suggested that the growth might be a rhabdomyosarcoma of the cardiac muscle, but careful search of many iron-haematoxylin-stained sections failed to reveal definite cross-striations,

Conzment: This tumour is clearly a rarity; we have been unable to dis- cover any previous record of a primary malignant tumour of the heart in an animal. Noteworthy were the extensive replacement of the heart wall by growth, its invasion of the right chambers, and the consequent formation of multiple blood-borne metastases in the lungs.


SUMMARY

Nine selected cases of malignant tumours in dogs are described, and their characters compared with the corresponding human tumours. The tumours described comprise carcinoma of the tonsil (two cases), carcinoma of the cardia of the stomach, carcinoma of the pancreas, carcinoma of the prostate, carcinoma of sweat glands, cystic and papillary carcinoma of the breast, mixed adenocarcinomatous and osteosarcomatous tumour of the thyroid, and a primary sarcoma of the heart.

REFERENCES

CHAVANNEZ, G., AND NADAL, I?.: Rev. de. chir. 43: 317, 1911. MCFADYEAN, J.: Practitioner 62: 456, 1899. FELDMAN, W. H.: Neoplasms of Domesticated Animals, Philadelphia, W. B. Saunders CO.,

FUNKENSTEIN, 0.: Virchows Archiv. f . path. Anat. 171: 34, 1903. MURRAY, J. A.: Third Scientific Report, Imperial Cancer Research Fund, London, 1908, pp.

STICKER, A.: Arch. f . klin. Chir. 65: 616, 1023, 1902. WILLIS, R. A.: The Spread of Tumours in the Human Body, London, J. A. Churchill, Ltd.,

1932.

41-60.

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MALIGNANT TUMOURS IN DOGS - Cancer ResearchMALIGNANT TUMOURS IN DOGS 209 which closely parallel those of some cases of intra-abdominal carcinoma in man (see Willis, 1934, pp. 387-88)