Table 6.3 Canine testicular tumours.

  Leydig cell Sertoli cell Seminoma
Frequency in descended testicles 40% 20% 40%
Frequency in undescended testicles Rare 60% 40%
Mean age 11.2 years 9.7 years 10 years
Size Benign adenomas - usually small and not noticed Slow growing but can become quite large (if intra-abdominal) Usually small
Other signs   Induces feminisation syndrome in male with: pendulous prepuce, atrophy of contralateral testicle and abnormal behaviour Can get acute signs due to haemorrhage or necrosis - similar to torsion
Metastases No 10-20% do 6-11% do
Diagnosis Incidental finding usually
Histopathology
Histopathology - fine needle aspirate cytology Histopathology - fine needle aspirate cytology
Treatment Castration - scrotal ablation is currently recommended by some authors Chemotherapy to reduce metastases pluss castration Chemotherapy to reduce metastases pluss castration
Prognosis Good Good unless disseminated Good unless disseminated