Slides from an aspirate of a mass on the left elbow of a two-year-old, intact male German Shepherd dog were submitted to the Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL) for examination. The slides had moderate numbers of macrophages, few multi-nucleated cells and neutrophils, and a large amount of brown staining material (mineralization). There were no bacteria, foreign bodies, or fungal hyphae or yeast seen. Few macrophages were phagocytizing small refractile structures (calcium crystals). It was determined the mass was a result of Calcinosis circumscripta.
Calcinosis circumscripta is the result of deposition of calcium salts in the subcutaneous tissue. The inciting cause is not completely understood but is thought to be due to chronic trauma/irritation as the lesions tend to occur over pressure points or at sites of previous trauma. Young large breed dogs are predisposed for this condition so it is possible active calcium and phosphorus metabolism may play a role. The aspirated material is characteristically a white gritty, chalky, or pasty material. Complete surgical excision is the treatment of choice.
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