Terms of Use httpsbiooneorgtermsofuse - PDF document

1 Terms of Use: https://bioone.org/terms-o
Terms of Use: https://bioone.org/terms-of-use Journal of Wildlife Diseases Vol. 18, No. 1, January. 1982 95 LEIOMYOSARCOMA AND PERIRENAL OSSEOUS METAPLASIA IN A RUSA HIND (C’ervus timoriensis) G. MITCHELL, I)epartment of Agriculture, Reg,onal Veterinary Laboratory, P.O. Box :188, Benalla, Victoria :3672, Australia. Abstract: A large mesenteric tumour in a Rusa hind (Cervus timoriensis) was diagnosed as a leiomyosarcoma on the basis of tumour size, degree of cellular pleomorphism, anaplasia, mitotic activity and evidence of local invasion. Rupture of the tumour and consequent haemorrhage was the immediate cause of death. Both kidneys were enclosed in bony masses which appeared to have replaced the normal perirenal fat. The bone was normal cancellous bone with active haemopoietic marrow. There did not appear to be any connection between the tumour and metaplastic perirenal bone. INTRODUCTION Leiomyosarcoma is a rare tumour in animals.i Hulland,’ suggests that only one tenth of smooth muscle tumours are leiomyosarcomas and that some of these should more properly be regarded as leiomyomas. In large animals, leiomyo- mas are most usually found in the uterus and vagina.’ The mesentery is an un- usual site for a smooth muscle tumour. metaplasia in the retroperi- toneum is not uncommon in pigs as a sequel to inflammation. The bony tissue is often found within adipose tissue and may occur in the mesentery and dorsal retroperitoneum wi

2 thout obvious inflam- matory change.2 Th
thout obvious inflam- matory change.2 This is a report of a mesenteric leiomyosarcoma associated with perirenal osseous metaplasia in a Rusa deer (Cervus timoriensis). CASE HISTORY A mature hind (Cervus timorien- sis) of unknown age was submitted to the laboratory for necropsy. She had been in estrus recently and had been pursued vigorously by the stag. She became atax- ic and incoordinated, finally becoming prostrate and dying overnight. A ten- tative diagnosis was made of trauma leading to fatal internal haemorrhage. At post-mortem examination, the mucous membranes were cyanotic icteric. The carcass showed a reasonable amount of body fat but was severely jaundiced. The abdomen contained ap- proximately 8 1 of free blood and fibrin clots. There was a 30 cm diameter tumour in the mesentery of the small intestine adherent to the caudal border of the liver. The mass had ruptured and contained a sizeable haematoma. The tumour was also caudally to a bony mass which enclosed the right kidney, a similar mass enclosed the left kidney. Their position corresponded to the usual distribution of perirenal fat. The cut surface of these bony masses showed areas of cancellous bone and necrotic fat. The mesenteric tumour had necrotic areas and showed extensive cavernous spaces occupied by haematoma. It was friable and apparently extensive fibrous stroma. There was no evidence of metastasis. Histologically the tumour consisted of interlacing

3 bundles of spindle-shaped to strap-like
bundles of spindle-shaped to strap-like cells with a tendency for the bundles to intersect at right angles. These cells were characterised by distinc- tive cigar-shaped, centrally placed nuclei (Figure 1). There were areas of marked cellular pleomorphism with anaplastic stellate or round cells and substantial FIGURE 1. Well differentiated, spindle shaped, smooth muscle cells with cigar- shaped nuclei. (- 12(i H & E) 96 Journal of Wildlife Diseases Vol. 18, No. 1. January. 1982 FIGURE 2. Multi-nucleate cells surrounded by anaplastic tumour cells. (X750 H & E) Journal of Wildlife Diseases Vol. 18, No. 1, January, 1982 97 Received for publication 26 August 1980 numbers of large multinucleate giant cells (Figure 2). Foci of small round cells with hyperchromatic nuclei and scant cytoplasm, resembling haemopoietic stem cells, were evident. Mitotic figures were not infrequent and the tumour demonstrated invasion of surrounding tissues. Collagenous fibrous stroma was minimal. Histologic examination of the perirenal bone showed it to be normal cancellous bone with active haemo- poietic marrow. There were no gross or histologic abnormalities of the enclosed kidneys. There was no histologic abnormality of the liver. DISCUSSION The diagnosis of leiomyosarcoma was based on the size, degree of necrosis, pleomorphism, anaplasia, mitotic activi- Acknowledgements ty and evidence of local invasion. In the description of the leiomyoma,’ emphasi

4 s is placed on the absence of pleomorphi
s is placed on the absence of pleomorphism and mitotic activity in the well- differentiated smooth muscle cells of the benign tumour.’ The presence of some typical strap-like smooth muscle cells with characteristic cigar-shaped nuclei and the relative absence of collagen serve to differentiate the tumour from a fibrosarcoma. It would appear that there was no connection between the presence of the leiomyosarcoma and the perirenal os- seous metaplasia. The reason for the latter is unknown. In the absence of demonstrable hepatic abnormality the marked jaundice of the carcass is most likely due to erythrocyte breakdown in the large area of haematoma and in the free peritoneal blood. I would like to thank Dr. D. Bostock, Veterinary Research Institute, Melbourne and Dr. N. Sullivan, Veterinary Clinical Centre, University of Melbourne, Werribee for their confirmation of this diagnosis; also Dr. C. Rosseaux for the reproduction of the photographs. LITERATURE CITED 1. HULLAND, T.J. 1978. Tumours of muscle. In: Tumors in Domestic Animals 2nd Ed., J.E. Moulton, Ed., University of California Press, Berkeley, Los Angeles and London. 2. JUBB, K.V.F. and P.C. KENNEDY. 1970. Pathology of Domestic Animals 2nd Ed., Vol. 2, Ch. 5, Academic Press, New York, San Francisco and London. 3. WEISS, E. 1974. International Histological Classification of Tumours of Domestic Animals. VIII. Tumours of the Soft (Mesenchymal) Tissues. Bull. W.H.O. 50: 101-1