The Discovery of the Parathyroid Gland: From Sir Richard Owen to Ivar Sandström

It is remarkable that one of the most vital glands in human physiology — regulating calcium, nerve conduction, and muscle contraction — remained hidden in plain sight for most of medical history. The parathyroid glands, tiny structures tucked discreetly behind the thyroid, were among the last major organs to be discovered. Their story is one of curiosity, persistence, and serendipity.

Sir Richard Owen: The First Observation (1852)

The discovery story begins with Sir Richard Owen (1804–1892), one of the most distinguished British anatomists and palaeontologists of the Victorian era. In 1852, while dissecting an Indian rhinoceros at the London Zoo, Owen observed a small ‘compact, yellowish glandular body’ attached to the thyroid gland. He described it in his paper ‘On the Anatomy of the Indian Rhinoceros’, recognizing it as an anatomical curiosity but not as a distinct gland.

At that time, the concept of endocrine glands and hormonal regulation was still emerging, and the thyroid itself was poorly understood. Owen’s observation was therefore pioneering but remained unappreciated for nearly three decades.

Ivar Sandström: The Definitive Discovery (1880)

The definitive discovery of the parathyroid gland is credited to Ivar Viktor Sandström (1852–1889), a young Swedish medical student at Uppsala University. In 1880, Sandström noticed small yellowish-brown nodules near the thyroid gland in a dog. He repeated his dissections in hundreds of animals and finally in human cadavers, confirming the consistent presence of these small structures. Sandström named them ‘glandulae parathyroideae’ — literally ‘beside the thyroid’.

He published his findings in Swedish in the journal *Upsala Läkareförenings Förhandlingar* under the title ‘On a New Gland in Man and Several Mammals’. Unfortunately, because of the language barrier and the limited circulation of the journal, his work initially went unnoticed. Sandström died at the young age of 37, before his discovery gained the recognition it deserved.

Vassale, Generali, and MacCallum: Discovering Its Function

In the 1890s, Italian physiologists Eugenio Vassale and Francesco Generali began experimental work on the parathyroids. They demonstrated that removing the glands in dogs caused muscle spasms, convulsions, and death — symptoms later identified as tetany due to low calcium levels.

At the turn of the 20th century, William G. MacCallum and Carl Voegtlin at Johns Hopkins University linked these symptoms to hypocalcemia and showed that calcium injections could reverse them. This established the parathyroid gland’s essential role in calcium homeostasis, laying the foundation for modern endocrine physiology.

A Legacy of Curiosity and Persistence

By the 1920s, the parathyroid hormone (PTH) had been identified, and its connection with bone metabolism and renal calcium regulation was well established. The gland, once overlooked and nearly forgotten, became central to the understanding and management of disorders such as hypocalcemia, hyperparathyroidism, and renal osteodystrophy.

The discovery of the parathyroid gland is a testament to scientific curiosity. Owen’s forgotten observation and Sandström’s meticulous anatomical work both highlight the importance of careful observation and persistence in scientific progress. It reminds us that even the smallest structures can hold the greatest significance — and that great discoveries often begin with small curiosities.

References

• Owen R. On the Anatomy of the Indian Rhinoceros. *Philosophical Transactions of the Royal Society of London*, 1852.
• Sandström I. Om en ny körtel hos menniskan och åtskilliga däggdjur. *Upsala Läkareförenings Förhandlingar*, 1880.
• Vassale E, Generali F. Sulla funzione delle glandole paratiroidee. *Archivio per le Scienze Mediche*, 1896.
• MacCallum WG, Voegtlin C. On the relation of the parathyroid glands to calcium metabolism. *Journal of Experimental Medicine*, 1908.