Orchidometer
Encyclopedia
An orchidometer is a medical instrument used to measure the volume
of the testicle
s.
The orchidometer was introduced in 1966 by pediatric endocrinologist Prof. Dr. Dr. hc. Andrea Prader of the University of Zurich
. It consists of a string of twelve numbered wooden or plastic beads of increasing size from about 1 to 25 millilitres. Doctor
s sometimes informally refer to them as "Prader's balls", "the medical worry beads", or the "endocrine rosary."
The beads are compared with the testicles of the patient, and the volume is read off the bead which matches most closely in size. Prepubertal sizes are 1–3 ml, pubertal sizes are considered 4 ml and up and adult sizes are 12–25 ml.
The orchidometer can be used to accurately determine size of testes. Discrepancy of testicular size with other parameters of maturation can be an important clue to various diseases. Small testes can indicate either primary or secondary hypogonadism
. Testicular size can help distinguish between different types of precocious puberty
. Since testicular growth is typically the first physical sign of true puberty, one of the most common uses is as confirmation that puberty is beginning in a boy with delay
. Large testes (macroorchidism
) can be a clue to one of the most common causes of mental retardation, fragile X syndrome
.
Professor Stephen Shalet, a leading endocrinologist who works for the Christie Hospital
in Manchester
, is reported to have told The Observer
, "Every endocrinologist should have an orchidometer. It's his stethoscope
."
Orchidometers are also commonly used to measure testicular volume in rams.
Volume
Volume is the quantity of three-dimensional space enclosed by some closed boundary, for example, the space that a substance or shape occupies or contains....
of the testicle
Testicle
The testicle is the male gonad in animals. Like the ovaries to which they are homologous, testes are components of both the reproductive system and the endocrine system...
s.
The orchidometer was introduced in 1966 by pediatric endocrinologist Prof. Dr. Dr. hc. Andrea Prader of the University of Zurich
University of Zurich
The University of Zurich , located in the city of Zurich, is the largest university in Switzerland, with over 25,000 students. It was founded in 1833 from the existing colleges of theology, law, medicine and a new faculty of philosophy....
. It consists of a string of twelve numbered wooden or plastic beads of increasing size from about 1 to 25 millilitres. Doctor
Physician
A physician is a health care provider who practices the profession of medicine, which is concerned with promoting, maintaining or restoring human health through the study, diagnosis, and treatment of disease, injury and other physical and mental impairments...
s sometimes informally refer to them as "Prader's balls", "the medical worry beads", or the "endocrine rosary."
The beads are compared with the testicles of the patient, and the volume is read off the bead which matches most closely in size. Prepubertal sizes are 1–3 ml, pubertal sizes are considered 4 ml and up and adult sizes are 12–25 ml.
The orchidometer can be used to accurately determine size of testes. Discrepancy of testicular size with other parameters of maturation can be an important clue to various diseases. Small testes can indicate either primary or secondary hypogonadism
Hypogonadism
Hypogonadism is a medical term for decreased functional activity of the gonads. Low testosterone is caused by a decline or deficiency in gonadal production of testosterone in males...
. Testicular size can help distinguish between different types of precocious puberty
Precocious puberty
As a medical term, precocious puberty describes puberty occurring at an unusually early age. In most of these children, the process is normal in every respect except the unusually early age, and simply represents a variation of normal development. In a minority of children, the early development is...
. Since testicular growth is typically the first physical sign of true puberty, one of the most common uses is as confirmation that puberty is beginning in a boy with delay
Delayed puberty
Puberty is described as delayed puberty with exceptions when an organism has passed the usual age of onset of puberty with no physical or hormonal signs that it is beginning. Puberty may be delayed for several years and still occur normally, in which case it is considered constitutional delay, a...
. Large testes (macroorchidism
Macroorchidism
Macroorchidism is the medical term used to describe a genetic disorder found in males where a subject has abnormally large testes. The condition is commonly inherited in connection with fragile X syndrome, which is also the second most common genetic cause of mental disabilities...
) can be a clue to one of the most common causes of mental retardation, fragile X syndrome
Fragile X syndrome
Fragile X syndrome , Martin–Bell syndrome, or Escalante's syndrome , is a genetic syndrome that is the most commonly known single-gene cause of autism and the most common inherited cause of intellectual disability...
.
Professor Stephen Shalet, a leading endocrinologist who works for the Christie Hospital
Christie Hospital
The Christie NHS Foundation Trust is located in Withington, Manchester, and is one of the largest cancer treatment centres in Europe. The Christie became a NHS Foundation Trust in April 2007 and is also an international leader in cancer research and development, and home to the Paterson Institute...
in Manchester
Manchester
Manchester is a city and metropolitan borough in Greater Manchester, England. According to the Office for National Statistics, the 2010 mid-year population estimate for Manchester was 498,800. Manchester lies within one of the UK's largest metropolitan areas, the metropolitan county of Greater...
, is reported to have told The Observer
The Observer
The Observer is a British newspaper, published on Sundays. In the same place on the political spectrum as its daily sister paper The Guardian, which acquired it in 1993, it takes a liberal or social democratic line on most issues. It is the world's oldest Sunday newspaper.-Origins:The first issue,...
, "Every endocrinologist should have an orchidometer. It's his stethoscope
Stethoscope
The stethoscope is an acoustic medical device for auscultation, or listening to the internal sounds of an animal body. It is often used to listen to lung and heart sounds. It is also used to listen to intestines and blood flow in arteries and veins...
."
Orchidometers are also commonly used to measure testicular volume in rams.
Further reading
- Prader, A., "Testicular size: Assessment and clinical importance", Triangle, 1966, vol. 7, pp. 240 - 243
- Taranger, J., Engström, I., Lichtensten, H., Svenberg-Redegren, I., "Somatic Pubertal Development", Acta Pediatr. Scand. Suppl. 1976, vol. 258, pp. 121 - 135