186                A Case of Equine Embryonal Nephroma

In the case under report four features of interest are observed. Firstly'
the presence of metastases on the peritoneum alone at once throws a sugges-
tion in favour of spread by contiguity and transplantation. Secondly, the
profuse formation of tubular glands is indicative of a more differentiated cell-
rest. In fact, had it not been for the presence of a mixed type of structure with
demonstrable sarcomatous areas, one would be inclined to label the growths
as metastasizing simple renal adenocarcinomata which, too, are known to arise
[Ewing, 1934] from well-differentiated renal blastema (also from tubules of
the adult kidney, in which case they are not embryonal).

The third notable feature, but one which should cause little surprise,
is the reported occurrence, following work, of haematuria which, however,
is regarded in human pathology as a clinical symptom suggesting a hyperne-
phroma, i.e., adrenal tissue tumour of the kidney (Boyd, 1934 ; Kettle, 1925).

Lastly, the involvement, apparently primarily, of the left kidney
may prove to be interesting, for in Mathews' [1929] twelve cases in chickens the
primary tumours were always present on the left side. No such information
is, however, available in connection with the tumours in other animals and,
therefore, it may be too early at present to attach any significance to the
phenomenon.

The author is greatly indebted to Capt. K. I. Barlow, Offg. Officer Com-
manding, Military Veterinary Hospital, Rawalpindi, for supplying the material
and information which have rendered possible the recording of this interesting
and rare condition.

                                        REFERENCES

Beattie, J. M. and Dickson, W. E. C. (1926). A Text-book of Pathology,
London, p. 917.
Boyd, W. (1934). A Text-book of Pathology, London, pp. 652-653.
Bremer, J. L. (1936). Text-book of Histology, Philadelphia, pp. 366-375,
Ewing, J. (1934). Neoplastic Diseases, London, pp. 65, 105 and 794-798.
Feldman, W. H. (1932). Neopl. Dom. Animals, London, pp. 357-372.
Jackson, C. (1936). Onderst. J. Vet. Sc. Anim. Husb. 6, 1, 349-353.
Kettle, E. H. (1925). The Pathology of Tumours, London, pp. 199-200.
MacCallum, W. G. (1932). A Text-book of Pathology, London, pp. 1136-1137.
Mathews, F. P. (1929). Adenosarcomata of the Kidneys of Chickens, J. Amer.
Vet. Med. Ass. 74, 238-246.
Wollstein, M. (1927). Cited by Feldman.