1) Primary Epithelial Tumors
:
a) Renal adenoma
-
rare; appears as a small solitary cortical mass.
b) Renal
adenocarcinoma
-
more common than adenoma,
particularly in dogs;
-
grossly, large compressive mass (up to 20 cm in diameter);
-
microscopically: neoplastic cells are in tubular or papillary arrangements;
c) Nephroblastoma (embryonal nephroma)
-
very common tumor in young pigs and chickens;
-
seen mostly as an incidental
finding at slaughter house;
-
large solitary mass or multiple masses which microscopically resemble fetal kidney;
-
can be benign or malignant.
d) Transitional cell papilloma
-
common
in animals; can be found in the mucosa of the renal pelvis, ureter or urinary bladder.
e) Transitional
cell carcinoma
-
the most commonly diagnosed tumor in the urinary bladder of domestic animals;
-
frequently metastasizes to regional lymph nodes and lungs.
2) Primary Mesenchymal Tumors:
-
Fibroma, Leiomyoma, Hemangioma (and malignant counterparts) are rare in
domestic
animals, except for those tumors associated with enzootic hematuria in cattle.
27
3) Secondary Tumors
-
Lymphosarcoma: common tumor that metastasizes to the kidneys and other tissues.
