Peer-reviewed veterinary case report
Hypercalcemia and high serum parathyroid hormone-related protein concentration in a horse with multiple myeloma.
- Journal:
- Journal of the American Veterinary Medical Association
- Year:
- 2004
- Authors:
- Barton, Michelle Henry et al.
- Affiliation:
- Department of Large Animal Medicine · United States
- Species:
- horse
Plain-English summary
A 13-year-old gelding (a male horse that has been castrated) was taken to the vet because he was losing weight and had high levels of certain proteins in his blood, along with high calcium levels. The vet considered several possible reasons for the high calcium, such as kidney failure or vitamin D poisoning, but ruled those out after testing. Initially, they suspected cancer, but further tests did not show any tumors. However, eight months later, a test showed a high level of a protein related to parathyroid hormone, which suggested that the high calcium was indeed due to cancer. Sadly, when the horse was put to sleep for humane reasons, an examination revealed cancer in multiple organs, confirming the diagnosis of multiple myeloma, a type of blood cancer.
Abstract
A 13-year-old gelding was examined because of weight loss, hyperglobulinemia, and hypercalcemia. Possible causes of hypercalcemia that were considered included renal failure, primary hyperparathyroidism, vitamin D toxicosis, and malignancy. There was no history of vitamin D ingestion, and serum creatinine and parathyroid hormone concentrations were normal, making renal failure and primary hyperparathyroidism unlikely. The hypercalcemia was suspected to be a result of malignancy, but thorough testing did not reveal any neoplastic disease. Eight months later, serum parathyroid hormone-related protein (PTHrP) concentration was high, supporting the suggestion that hypercalcemia was a result of malignancy. In addition, radial immunodiffusion confirmed a selective 300-fold increase in serum IgA concentration. The horse was euthanatized, and postmortem examination revealed neoplastic infiltrates in the kidneys, lymph nodes, liver, and bone marrow. Neoplastic cells had morphologic characteristics of plasma cells, and immunohistochemical staining confirmed that neoplastic cells were expressing PTHrP and IgA. The final diagnosis was multiple myeloma with expression of IgA paraprotein.
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Search related cases →Original publication: https://pubmed.ncbi.nlm.nih.gov/15328717/