Gastrict carcinoma with pseudohyperparathyroidism in a horse.

This research article examines a case where a mature male horse showed symptoms similar to hyperparathyroidism, which led to the diagnosis of stomach squamous cell carcinoma, a type of cancer.

Case Presentation

• A mature stallion was brought to the clinic showing signs of not eating (anorexia), losing weight, frequently urinating (pollakiuria) and being constipated. These symptoms led to the suspicion of pseudohyperparathyroidism, a condition in which the body behaves as if it’s producing too much parathyroid hormone, a type of hormone that controls calcium levels in the bloodstream and tissues.

Laboratory Findings

• The blood tests of the horse showed high levels of calcium (hypercalcemia) and low levels of phosphate (hypophosphatemia), in addition to anemia and isosthenuria (urine that has the same specific gravity as plasma). These readings further pointed to pseudohyperparathyroidism.

Thoracocentesis and Diagnosis

• Upon performing a thoracocentesis, a procedure where a needle is inserted into the chest to remove fluid, exfoliating squamous cell carcinoma cells were found. This led to a diagnosis of squamous cell carcinoma of the stomach. This type of cancer originates from the squamous cells that are found in the skin and the tissues that line the stomach.

Necropsy Findings

• The post-mortem examination (necropsy) found that the squamous cell carcinoma had spread (metastasized) to the abdomen and thoracic cavities. There were no signs of the cancer having spread to the bones (osseous metastases) and neither were there any noticeable damage to the kidneys under the naked eye or even when viewed under a microscope. Additionally, the bones showed that they had stopped reabsorbing bone tissue (arrested resorption), and the parathyroid gland, which often is enlarged in cases of hyperparathyroidism, was found to have shrunk (atrophic).