Something interesting I learnt in the operating room…the origin of the parathyroids.

During my final year in medical school, I was fortunate enough to be assigned to a friendly endocrine surgeon as my supervisor. I scrubbed in with him on multiple procedures where he stressed the importance of correct adrenergic blockade during resections of phaeochromocytomas and also how to manage potentially devastating haematomas following neck surgery.

One of the most interesting things he spoke about was the discovery of the parathyroid glands, which were the last grossly visible human organs to be identified. In 1834, the London Zoological Society purchased a female Indian rhinoceros, Rhinoceros unicornis, by the name of Clara, at the request of the anatomist, Richard Owen. Some claim the rhinoceros was a male and that researchers were trying to identify the organ which allowed male rhinoceros to engage in sexual intercourse for hours at a time2 , but this is a point of contention¹. The rhinoceros was a popular attraction. In 1849, she died from traumatic injuries after her ribs were broken during a fight with an elephant, and Owen performed a necropsy^2*.

During the necropsy, Owen found a small, yellow glandular body attached to the thyroid gland. He had never seen a gland like this before, so he named it the “parathyroid gland.” In his paper to the Zoological Society of London, he described the gland as follows: a small compact yellow glandular body was attached to the thyroid at the point where the veins emerge. Owen’s discovery of the parathyroid gland was a significant event in the history of medicine. The parathyroid glands are responsible for secreting parathyroid hormone, which regulates calcium levels in the blood. Without parathyroid hormone, calcium levels would drop dangerously low, leading to tetany.

Owen’s discovery of the parathyroid glands was not immediately recognized by the scientific community. In 1889, Ivar Sandström gave the parathyroid glands their modern name, and he is credited with being the first to fully describe their anatomy, function and demonstrate their presence across multiple species including humans. His paper detailing this discovery was the only paper he published as due to poor mental health he took his own life aged 37 years old.

The discovery of the parathyroid glands has had a major impact on the treatment of thyroid cancer. In the past, it was common for surgeons to remove the entire thyroid gland during thyroidectomy. However, this often led to hypoparathyroidism. Today, surgeons are more careful to preserve the parathyroid glands during thyroidectomy. In addition to the medical significance of the discovery, the story of the parathyroid glands and the rhinoceros is also a reminder of the importance of curiosity and observation in science. Owen was a meticulous anatomist, and his willingness to question the status quo led to a major breakthrough in our understanding of the human body.