Polyorchidism is the incidence of

more than two ''More Than Two'' is a non-fiction book about consensual non-monogamous relationships. The first edition, ''More Than Two: A Practical Guide to Ethical Polyamory,'' written by Franklin Veaux and Eve Rickert, was published in 2014 by Thorntree P ...

testicle A testicle or testis (plural testes) is the male reproductive gland or gonad in all bilaterians, including humans. It is homologous to the female ovary. The functions of the testes are to produce both sperm and androgens, primarily testostero ...

s. It is a very rare

congenital disorder A birth defect, also known as a congenital disorder, is an abnormal condition that is present at birth regardless of its cause. Birth defects may result in disabilities that may be physical, intellectual, or developmental. The disabilities can ...

, with fewer than 200 cases reported in medical literature and six cases (two horses, two dogs and two cats) in veterinary literature. Polyorchidism is generally diagnosed via an

ultrasound Ultrasound is sound waves with frequency, frequencies higher than the upper audible limit of human hearing range, hearing. Ultrasound is not different from "normal" (audible) sound in its physical properties, except that humans cannot hea ...

examination of the testicles. However, the diagnosis of polyorchidism should include histological confirmation. The most common form is triorchidism, or tritestes, where three testicles are present. The condition is usually

asymptomatic In medicine, any disease is classified asymptomatic if a patient tests as carrier for a disease or infection but experiences no symptoms. Whenever a medical condition fails to show noticeable symptoms after a diagnosis it might be considered asy ...

. A man who has polyorchidism is known as a polyorchid.

Classification

Polyorchidism occurs in two primary forms: Type A and Type B. * Type A: The supernumerary testicle is connected to a vas deferens. These testicles are usually reproductively functional. Type A is further subdivided into: ** Type A1: Complete duplication of the testicle,

epididymis The epididymis (; plural: epididymides or ) is a tube that connects a testicle to a vas deferens in the male reproductive system. It is a single, narrow, tightly-coiled tube in adult humans, in length. It serves as an interconnection between the ...

and vas deferens. ** Type A2: The supernumerary testicle has its own epididymis and shares a vas deferens. ** Type A3: The supernumerary testicle shares the epididymis and the vas deferens of the other testicles. * Type B: The supernumerary testicle is not connected to a vas deferens and is therefore not reproductively functional. Type B is further subdivided into: ** Type B1: The supernumerary testicle has its own epididymis but is not connected to a vas deferens ** Type B2: The supernumerary testicle consists only of testicular tissue. Type A3 is the most common form of polyorchidism, and types A2 and A3 together account for more than 90% of cases. In 65% of cases, the supernumerary testicle is found in the left scrotal sac.

Numeric system

An older system of classification structures polyorchidism into similar types, but with no subdivision between connected and disconnected testicles: * Type 1: The supernumerary testicle lacks an

and vas deferens and has no connection to the other testicles. * Type 2: The supernumerary testicle shares the epididymis and the vas deferens of the other testicles. * Type 3: The supernumerary testicle has its own epididymis and shares a vas deferens. * Type 4: Complete duplication of the testicle, epididymis and vas deferens.

Cause

Complications

Most cases of polyorchidism are

, and are discovered incidentally, in the course of treating another condition. In the majority of cases, the supernumerary testicle is found in the scrotum. However, polyorchidism can occur in conjunction with

cryptorchidism Cryptorchidism, also known as undescended testis, is the failure of one or both testes to descend into the scrotum. The word is from Greek () 'hidden' and () 'testicle'. It is the most common birth defect of the male genital tract. About 3% of ...

, where the supernumerary testicle is undescended or found elsewhere in the body. These cases are associated with a significant increase in the incidence of testicular cancer: 0.004% for the general population vs 5.7% for a supernumerary testicle not found in the scrotum. Polyorchidism can also occur in conjunction with

infertility Infertility is the inability of a person, animal or plant to reproduce by natural means. It is usually not the natural state of a healthy adult, except notably among certain eusocial species (mostly haplodiploid insects). It is the normal state ...

inguinal hernia An inguinal hernia is a hernia (protrusion) of abdominal-cavity contents through the inguinal canal. Symptoms, which may include pain or discomfort especially with or following coughing, exercise, or bowel movements, are absent in about a third ...

, testicular torsion,

epididymitis Epididymitis is a medical condition characterized by inflammation of the epididymis, a curved structure at the back of the testicle. Onset of pain is typically over a day or two. The pain may improve with raising the testicle. Other symptoms may ...

, hydrocele testis and

varicocele varicocele is an abnormal enlargement of the pampiniform venous plexus in the scrotum. This plexus of veins drains blood from the testicles back to the heart. The vessels originate in the abdomen and course down through the inguinal canal as part ...

. However, it is not clear whether polyorchidism causes or aggravates these conditions, or whether the existence of these conditions leads sufferers to seek medical attention and thus become diagnosed with a previously undetected supernumerary testicle.

Management

Because polyorchidism is very uncommon, there is no standard treatment for the condition. Prior to advances in ultrasound technology, it was common practice to remove the supernumerary testicle. Several cases have been described where routine follow-up examinations conducted over a period of years showed that the supernumerary testicle was stable. A

meta-analysis A meta-analysis is a statistical analysis that combines the results of multiple scientific studies. Meta-analyses can be performed when there are multiple scientific studies addressing the same question, with each individual study reporting me ...

in 2009 suggested removing non-scrotal supernumerary testicles because of the increased risk of cancer, and regular follow-up in the remaining cases to ensure that the supernumerary testicle remains stable.

References

External links

{{Authority control Supernumerary body parts Congenital disorders of male genital organs Rare diseases Testicle Intersex variations