[A case of osteosarcoma in a white polar bear].

A male polar bear was caught at the Franz Josef Land at the age of 1 year and then lived in Moscow ZOO for 6 years. Thickening of the distal part of the right hind limb was noted in 1993. Destructive changes in the region of epymetaphysis were observed roentgenologically suggesting osteolytic osteosarcoma.

[Steroid hormone receptors in spontaneous testicular tumors in dogs].

Cytoplasmic receptors to androgens (AR), estrogens (ER), progesterone (PR) and glucocorticoids (GR) were studied in tumors and normal tissue of the testis in dogs. Peculiarities of distribution of receptors were assessed versus age and tumor histology. Benign Leydig cell tumors failed to reveal AR and ER.

[The morphological characteristics of lymphoid hemoblastoses in dogs].

125 autopsy cases of hemoblastoses in dogs are studied, their morphology was adequate to that in humans. Lymph proliferative diseases are more frequent in dogs. New morphological variants of lymphoid hemoblastosis are distinguished, which have not been yet included into the WHO International Histologic Classification of tumours in domestic animals.