JPC SYSTEMIC PATHOLOGY
Signalment (JPC #82-2228): Angora Goat
HISTORY: Tissue from an Angora goat. On examination the kidneys appeared uniformly brown. Upon transection, the discoloration was found to be limited to the cortices of both kidneys
HISTOPATHOLOGIC DESCRIPTION: Kidney: Approximately 40% of the proximal convoluted tubules within the renal cortex have thickened, 8-12 micron wide, reddish brown to black pigmented basement membranes. Rarely, tubules contain granular basophilic material (mineral).
MORPHOLOGIC DIAGNOSIS: Kidney, cortex, proximal convoluted tubules, basement membrane: Pigmentation, multifocal, moderate, Angora, caprine.
CONDITION: Cloisonné kidney
- Nonclinical pigmentary condition in goats
- Does not interfere with renal function
- Name derived from the resemblance of the microscopic pattern to the cloisonné technique of inlay of metal wire in porcelain
- A hemolytic pathogenesis has been suggested
- Low levels of erythrocytic glucose-6-phosphate dehydrogenase and glutathione, plus elevated serum-iron binding saturation, predispose erythrocytes to fragility
- Ferritin and hemosiderin are deposited, presumed to bethe result of repeated episodes of intravascular hemolysis
- Basement membrane thickening is postulated to be due to ferritin and hemosiderin deposition; however the chemical nature of the material has not been established and usually it does not stain for iron
TYPICAL GROSS FINDINGS: Uniform brown-black discoloration throughout the renal cortex, stopping abruptly at the corticomedullary junction
TYPICAL LIGHT MICROSCOPIC FINDINGS: Curving, wire-like dark brown to gray/brown pigmented thickening of the basement membranes of proximal convoluted tubules
Gross: renal hemosiderosis, post-mortem discoloration, hemoglobinuric nephrosis (gunmetal blue kidney)
The gross appearance, with the discoloration affecting only the cortex and stopping abruptly at the cortico medullary junction differentiates from all other entities
COMPARATIVE PATHOLOGY: Described only in the goat
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- Jones TC, Hunt RD, King NW. Urinary system. In: Veterinary Pathology. 6th ed. Baltimore, MD: Williams and Wilkins; 1997:1131-1132.
- Breshears MA, Confer AW. The urinary system. In: McGavin MD, Zachary JF, ed. Pathologic Basis of Veterinary Disease. 6th ed. St. Louis, MO: Elsevier Mosby; 2016:628.