Failure of Technetium Tc 99m Sestamibi Scanning to Detect Abnormal Parathyroid Tissue in a Horse and a Mule with Primary Hyperparathyroidism

Primary hyperparathyroidism in a 17‐year‐oldArab ×WelshCob pony mare with a functional parathyroid adenoma

“…and a 99m Tc‐sestamibi scintigraphic scan of the neck was performed from the ramus of the mandible to the thoracic inlet (Wong et al . ). Lateral and ventrodorsal images were acquired at 15 and 45 min, and 1, 2, 3, 4, 6 and 8 h, after intravenous administration of 2.5 GBq 99m Tc‐sestamibi (Cardiolite) 10 , using a large field‐of‐view scintillation camera with a low energy, all‐purpose collimator Nucline X‐Ring/R 11 , and processed using software MicasXplus Version 5.2 12 software.…”

“…; Wong et al . ). Clinical signs of primary hyperparathyroidism in the horse include weight loss, facial swelling, inappetence, difficulty eating and shifting lameness (Frank et al .…”

“…; Wong et al . ; Tomlinson et al . ) or parathyroid hyperplasia (Toribio ), or may be idiopathic (Roussel and Thatcher ; Frank et al .…”

“…Although technetium ( 99m Tc)‐sestamibi scintigraphy is frequently used in human patients to locate abnormal parathyroid tissue, the use of this technique in the horse has met with mixed success (Wong et al . ; Tomlinson et al . ).…”

Successful Detection and Removal of a Functional Parathyroid Adenoma in a Pony Using Technetium Tc 99m Sestamibi Scintigraphy

“…Equids have 2 pairs of parathyroid glands, with the caudal pair located anywhere along the carotid arteries from the cranial cervical region to the thymus,2 making detection of an adenoma by ultrasonography alone difficult. Technetium Tc 99m sestamibi has been used successfully in humans and dogs to detect parathyroid adenomas, but recent attempts in horses have not been successful 2…”