title: A malignant nephroblastoma in an aged fox (Fennecus zerda).
abstract: A malignant nephroblastoma with pulmonary metastasis which was found at necropsy in an old fox is described. This is the first report of such a tumour in a fox. Nephroblastoma is rare in the family Canidae and usually occurs in young individuals. The presence of a tumour arising from embryonal tissue in an aged animal raises questions about the genesis and behaviour of this tumour. The tumour may have contributed to the animal's congestive heart failure as a result of the generalized pulmonary involvement, an erythropoietin-induced polycythaemia, or increased peripheral resistance via the renin-angiotensin system.
mesh_terms: D000818:Animals; D005589:Foxes; D007680:Kidney Neoplasms / Q000473:pathology / Q000662:veterinary*; D008297:Male; D009396:Wilms Tumor / Q000473:pathology / Q000662:veterinary*