Monorchism (also monorchidism) is the state of having only one

testicle A testicle or testis ( testes) is the gonad in all male bilaterians, including humans, and is Homology (biology), homologous to the ovary in females. Its primary functions are the production of sperm and the secretion of Androgen, androgens, p ...

within the

scrotum In most terrestrial mammals, the scrotum (: scrotums or scrota; possibly from Latin ''scortum'', meaning "hide" or "skin") or scrotal sac is a part of the external male genitalia located at the base of the penis. It consists of a sac of skin ...

Terminology

An individual having monorchism can be referred to as ''monorchid''.

Causes

This can be due to one testicle: * Not descending into the scrotum during normal

embryo An embryo ( ) is the initial stage of development for a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male sp ...

nic or

fetal A fetus or foetus (; : fetuses, foetuses, rarely feti or foeti) is the unborn offspring of a viviparous animal that develops from an embryo. Following the embryonic stage, the fetal stage of development takes place. Prenatal development is a ...

development (3–4% of "normal" live births), also known as undescended testis or cryptorchidism. In this case the testis is within the abdominal cavity, somewhere along the normal route of descent – most commonly, within the

inguinal canal The inguinal canal is a passage in the anterior abdominal wall on each side of the body (one on each side of the midline), which in males, convey the spermatic cords and in females, the round ligament of the uterus. The inguinal canals are lar ...

. Such a testis has an increased risk of

malignancy Malignancy () is the tendency of a medical condition to become progressively worse; the term is most familiar as a characterization of cancer. A ''malignant'' tumor contrasts with a non-cancerous ''benign'' tumor in that a malignancy is not ...

. * Disappearing during development (the so-called vanishing testis) due to some intrauterine insult. This is thought to be most likely

vascular Vascular can refer to: * blood vessels, the vascular system in animals * vascular tissue Vascular tissue is a complex transporting tissue, formed of more than one cell type, found in vascular plants. The primary components of vascular tissue ...

, such as testicular torsion. * Not being created in the first place (gonadal agenesis), known as ''congenital'' monorchism. (As of 1974, this was believed to occur in roughly 1 in every 5,000 people with a male phenotype. In contrast, absence of ''both'' testes, known as congenital anorchism, was believed to occur in roughly 1 in 20,000.) * Being surgically removed through

orchiectomy Orchiectomy (also named orchidectomy) is a surgery, surgical procedure in which one or both testicles are removed. The surgery can be performed for various reasons: *treatment for testicular cancer *as part of gender-affirming surgery for trans ...

. * Being injured.

Notable cases

Due to testicular cancer

Lance Armstrong Lance Edward Armstrong (''né'' Gunderson; born September 18, 1971) is an American former professional road bicycle racing, road racing cyclist. He achieved international fame for winning the Tour de France a record seven consecutive times fro ...

, American bicyclist. * Frank Church, former U.S. Senator and Presidential candidate. * Tom Green,

Canadian Canadians () are people identified with the country of Canada. This connection may be residential, legal, historical or cultural. For most Canadians, many (or all) of these connections exist and are collectively the source of their being ''C ...

comedian-actor. * Richard Herring, English comedian and writer * John Kruk, former baseball player *

Mark Latham Mark William Latham (; born 28 February 1961) is an Australian politician and media commentator who is a member of the New South Wales Legislative Council. He previously served as the leader of the Australian Labor Party (ALP) and Leader of the ...

, former

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

n politician. * Geoff Horsfield, English footballer. * Nenê,

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

ian basketball player. * Kevin Curtis, American football player. *

Nigel Farage Nigel Paul Farage ( ; born 3 April 1964) is a British politician and broadcaster who has been Member of Parliament (United Kingdom), Member of Parliament (MP) for Clacton (UK Parliament constituency), Clacton and Leader of Reform UK since 20 ...

, former leader of the

UK Independence Party The UK Independence Party (UKIP, ) is a Eurosceptic, right-wing populist political party in the United Kingdom. The party reached its greatest level of success in the mid-2010s, when it gained two members of parliament (both through defect ...

. *

Bobby Moore Robert Frederick Chelsea Moore (12 April 1941 – 24 February 1993) was an English professional footballer. He captained West Ham United for more than ten years, and was the captain of the England national team that won the 1966 FIFA ...

, English footballer and World Cup winner. *

Jimmy White James Warren White (born 2 May 1962) is an English professional snooker player who has won ten ranking events. Nicknamed "The Whirlwind" because of his swift and attacking style of play, White has reached six World Snooker Championship finals ...

, English snooker player. * Darren Kendall, former master of the noseflute.

Due to injury

* Archibald Douglas, 4th Earl of Douglas, magnate of the Kingdom of Scotland, and Peer of France. Lost in 1403, while fighting at the Battle of Shrewsbury (The previous year he had lost an eye at the Battle of Homildon Hill). *

Troy Bayliss Troy Andrew Bayliss (born 30 March 1969 in Taree, New South Wales, Australia) is an Australian motorcycle racer. During his career Bayliss won the Superbike World Championship three times and a MotoGP race, all with Ducati. He finished his care ...

, world

superbike A sports motorcycle, sports bike, or sport bike is a motorcycle designed and optimized for speed, acceleration, braking, and cornering on asphalt concrete race tracks and roads. They are mainly designed for performance at the expense of comfor ...

champion in 2001, 2006 and 2008. In 2007 he lost a testicle during a race at Donington Park. * Brian Foster, American mixed martial artist. * John Starks, American basketball player. * Paul Wood, English

rugby league Rugby league football, commonly known as rugby league in English-speaking countries and rugby 13/XIII in non-Anglophone Europe, is a contact sport, full-contact sport played by two teams of thirteen players on a rectangular Rugby league playin ...

player who sustained a ruptured testicle during a match and subsequently had it removed. *

Thurgood Marshall Thoroughgood "Thurgood" Marshall (July 2, 1908 – January 24, 1993) was an American civil rights lawyer and jurist who served as an associate justice of the Supreme Court of the United States from 1967 until 1991. He was the Supreme C ...

, United States Supreme Court Justice who injured a testicle during a fraternity event in university. * Dave England, who lost one of his testicles after suffering a double

hernia A hernia (: hernias or herniae, from Latin, meaning 'rupture') is the abnormal exit of tissue or an organ (anatomy), organ, such as the bowel, through the wall of the cavity in which it normally resides. The term is also used for the normal Devel ...

during a snowboard accident in New Zealand in 1997.

Due to cryptorchidism

Mao Zedong Mao Zedong pronounced ; traditionally Romanization of Chinese, romanised as Mao Tse-tung. (26December 18939September 1976) was a Chinese politician, revolutionary, and political theorist who founded the People's Republic of China (PRC) in ...

, founder of the People's Republic of China.

Due to congenital monorchism

* Dara Ó Briain, Irish comedian related that he has a single testicle in a standup routine.

Unknown

* Possible monorchism of Adolf Hitler * Jon Paulson *

Francisco Franco Francisco Franco Bahamonde (born Francisco Paulino Hermenegildo Teódulo Franco Bahamonde; 4 December 1892 – 20 November 1975) was a Spanish general and dictator who led the Nationalist faction (Spanish Civil War), Nationalist forces i ...

, Dictator of Spain.

Monorchism in nonhuman animals

Although extremely rare, monorchism has been observed to be characteristic of some animal species, notably in beetles.

References

{{Male congenital malformations of genital organs, indeterminate sex and pseudohermaphroditism