Primary hyperparathyroidism in an adult female olive baboon (Papio anubis)

During an annual physical examination, a middle-aged adult female olive baboon (Papio anubis) in the time-mated breeding colony at the Biologic Resources Laboratory at the University of Illinois at Chicago was found to have a high serum calcium value (> 12 mg/dl). To determine the cause of the hypercalcemia, additional diagnostic tests, including thoracic and abdominal radiographs and a parathyroid panel (parathyroid hormone (PTH), ionized calcium, and parathyroid hormone-related protein (PTH-rp) assays), were performed. The radiographs did not reveal lesions suggestive of neoplasia. A parathyroid panel was obtained twice. Both times the PTH (23.4 and 46.4 pmol/L, normal = 2.91 to 4.57 pmol/L) and ionized calcium (1.68 and 2.10 mmol/L, normal = 1.31 to 1.37 mmol/L) were increased above values for adult females with normal calcium concentration. A tentative diagnosis of primary hyperparathyroidism was made. After a gamma-radiation scan and magnetic resonance imaging of the neck were done, exploratory surgery was performed to identify and remove the affected gland. After gland removal, the baboon's serum calcium, PTH (1.6 pmol/L), and ionized calcium (1.59 mmol/L) values decreased. Results of histologic examination confirmed the diagnosis of benign solitary parathyroid adenoma.