Hektoen International

A Journal of Medical Humanities

History of ectopic kidney

Mostafa Elbaba
Doha, Qatar

Bayard Taylor Holmes. Medical Life vol. 31, 1924. Via Wikimedia.

There are many errors in the development of the kidneys which are of great surgical and pathologic interest. Most of these errors are easily explainable by the remarkable evolutions which attend the development of the urinary apparatus. If anyone doubts the utility of a careful study of this subject, let him contemplate the feelings of the surgeon who has removed the only kidney a patient possessed, or of one who has explored the loin and found no kidney below the supra-renal capsule. Congenital errors in the development of the kidney occur with about the same frequency as do malformations elsewhere in the body. In 13,478 autopsies, one kidney was entirely absent in 4 cases, and atrophic in 59 cases.
— Bayard Taylor Holmes, 18971

The kidneys develop in the pelvis during the embryo’s fourth week. Between the sixth and ninth week, they normally ascend to the lumbar area, rotate their position to face medially, and take new branches from the dorsal aorta that eventually develop into the renal arteries. By the ninth week of gestation, they will have attained their adult positions.2

Ectopic kidneys (renal ectopia) result if the ascent of the kidneys is arrested, so that they stay in the pelvis (pelvic kidney). They may just stay in their lower in position (lumbar), cross to the other side with or without fusion (crossed ectopia) or even become located in the thorax. One or both kidneys may be affected and fail to ascend from the pelvis.3 It may have a shortened ureter and blood supply from the adjoining large vessels. Variations of the various anomalies were initially described and classified in 1938 by Harry Wilmer, then refined and expanded by James McDonald and Don McClellan in 1957.4,5

Page from Caspari Bauhini Basileensis Theatrvm Anatomicum by Caspar Bauhin. Johann Theodor de Bry, 1605. Bayerische StaatsBibliothek. CC BY-NC-SA 4.0.

Ectopic kidneys were known to the early anatomists, diagnosed in anatomical specimens at autopsy and at operations.6 Swiss botanist and physician Gaspard Bauhin, also known as Caspar Bauhin, was the first to describe in 1592 a left kidney situated at the bifurcation of the aorta in front of the cecum and supplied by vessels from the right iliac artery and aorta.7,8 Later, many cases of renal ectopia were reported through anatomical dissections, by Leonardo Botallo (1530–1587), Bartolomeo Eustachi (1510–1574), and Antonio Valsalva (1666–1723).9

At first the diagnosis of absent kidney (agenesis or ectopic) could only be made by opening the abdomen. In the nineteenth century, the practical thinking about ectopic kidney was raised by surgeons, especially during traumatic abdominal surgery. They were surprised to find no kidney in its expected anatomical place, discovering it instead accidentally in an ectopic position.10 More cases were reported after the German urologist Maximilian Nitze (1848–1906) invented the modern cystoscope and it became for general use in 1879. Even later, more cases were recognized in the 1920s after Leonard Rowntree developed intravenous pyelography. This was later replaced by contrast computed tomography and even later by ultrasonography.11 Advances in prenatal diagnosis in the last decades using fetal ultrasonography have also made it possible to reliably diagnose fetal ectopic kidney beyond 24 weeks’ gestation,12 and this can now be also achieved reliably by technetium-99m nuclear medicine studies. As the technetium-99m DMSA binds to the proximal convoluted tubules in kidney, it can be used reliably to detect any renal ectopia.2


  1. Holmes, Bayard. “Surgery of the Kidney.: Being a Study of a Series of Cases in Which Methods of Diagnosis and Treatment are Illustrated.” Journal of the American Medical Association 28, no. 17 (1897): 769-773.
  2. Bingham G, Leslie SW. Pelvic Kidney. [Updated 2023 May 30]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan.
  3. Thomas, Gilbert J., and J. C. Barton. “Ectopic pelvic kidney.” Journal of the American Medical Association 106, no. 3 (1936): 197-201.
  4. Wilmer, Harry A. “Unilateral fused kidney: a report of five cases and a review of the literature.” Journal of Urology 40, no. 5 (1938): 551-571.
  5. McDonald, James H., and Don S. McClellan. “Crossed renal ectopia.” American Journal of Surgery 93, no. 6 (1957): 995-1002.
  6. Kher, Kanwal, H. William Schnaper, and Sudesh Paul Makker, eds. Clinical pediatric nephrology. CRC Press, 2006.
  7. Hawes, Cecil J. “Congenital unilateral ectopic kidney: a report of two cases.” Journal of Urology 64, no. 3 (1950): 453-456.
  8. Manley, Thomas H. “IV. Contribution to Traumatic Abdominal Surgery: I. Report of a Case of Contusion and Subsequent Gangrene of a Portion of the Ileum, Complicated by Laceration of a Horseshoe Kidney. II. Report of a Case of Gangrenous Strangulated Hernia.” Annals of Surgery 25, no. 4 (1897): 454.
  9. Darner, H. Lauran. “Bilateral ectopic kidneys.” J. Urology 12 (1924): 193-214.
  10. Tolson, Howard L. “Ectopic (pelvic) kidney.” Annals of Surgery 93, no. 4 (1931): 880.
  11. Osborne, Earl D., Charles G. Sutherland, Albert J. Scholl, and Leonard G. Rowntree. “Roentgenography of urinary tract during excretion of sodium iodid.” Journal of the American Medical Association 80, no. 6 (1923): 368-373.
  12. Batukan, C., and Atıl Yuksel. “Prenatal diagnosis and postnatal outcome of pelvic kidneys.” Prenatal Diagnosis 31, no. 4 (2011): 356-359.

MOSTAFA ELBABA is an Egyptian pediatric nephrologist. He graduated and received his master’s degree from Ain Shams University. In 2011, he settled in Hamad Medical Corporation in Qatar. He has a master’s degree in medical education and advanced certification in simulation. Apart from medical qualification, he is a public writer and author and is certified in arts, history of medicine, and religions. 

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