Lesion as a background change in Cynomolgus monkey kidneys

Has anyone else seen this type of lesion as a background change in Cynomolgus monkey kidneys?

This is a control, Mauritian-origin male (noted in females as well), 3-5 years old. There are typically multiple foci/animal; the needle-shaped crystalline material is present some of the time only, and is typically this blue-grey color on H&E (although it can be darkly pigmented/brown on occasion). Sometimes rather than crystalline material there is a homogenous to slightly granular eosinophilic material. Granulomas tend to be at the corticomedullary junction. The kidneys with these granulomas also tend to have a higher severity of the background lesion some refer to as interstitial nephritis. Thoughts?


Spontaneous lesion

June 9, 2015 11:45 AM by Karyn Colman, BVetMed, MRCVS

Probable oxalate crystals

June 26, 2015 12:18 PM by JoAnn C L Schuh, DVM, PhD, DACVP, DABT

Similar changes have been reported as oxalate crystals. Probably due to oxalates in the diet.

Sato J, Doi T, Kanno T, Wako Y, Tsuchitani M, Narama I. Histopathology of Incidental Findings in Cynomolgus Monkeys (Macaca Fascicularis) Used in Toxicity Studies. Journal of Toxicologic Pathology. 2012;25(1):63-101. doi:10.1293/tox.25.63.

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