Abnormally small testicles (testicular volume < 12 ml in adult men) may appear due to several causes. Specifically, there are genetic predispositions (syndromes), infections, malformations, testicular traumatic injuries and intoxication by some drugs that can cause the testicular atrophy (the male reproductive organs diminish in size and may be accompanied by loss of function) or testicular underdevelopment. The function of small testicles is most often maintained but significantly reduced making natural conception more difficult.
The most common instrument used to measure testicular size is called orchidometr (Pic. 1) and consist of testicle-shaped beads differentiating in their size according to specific volumes. This instrument is based upon the fact, that impaired spermatogenesis (the process of sperm production) if often accompanied by small-volume testicles. The normal testicular volume of adult men should be between 12 – 20 ml (Asian males have typically smaller testes, man of other races should have at least testicles matching the 20ml bead).
Genetically predisposed syndromes
To name some genetically predisposed syndromes that are affecting male reproduction capacity and manifest by small testicles, the Klinefelter’s syndrome can be named, as well as the Kenny – Caffey syndrome, Prader – Willi syndrome, Kallmann syndrome or 46, XX testicular disorder of sex development (also known as 46.XX male syndrome). All these syndrome happens to negatively influence the hormonal balances within the human body affecting the function of whole body, resulting in physiological, behavioural and visage changes. As an example of testicular underdevelopment related to genetically predisposed syndrome, a man suffering from Klinefelter’s syndrome has testicles of approximately 5 ml volumes (4 times smaller than regular testicular size of an adult man).
Infections: Mumps
The mumps can serve as typical example of infection that manifests by the presence of small testicles. It is a viral disease of parotid glands that was commonly affecting children in entire world, but now days a vaccination is available. Mumps are highly contagious and spread through contact with respiratory secretions of infected person. The disease can spread into testicular tissue causing an inflammation which can lead also to development of testicular atrophy resulting in small volume testicles.
Malformations: Varicocele
The malformation of venomous network around testicles consisting in enlargement of blood-vessels is called varicocele and it is also connected with small testicular size. Varicocele effects include elevated temperature, adrenal hormone reflux, gonadotoxic metabolite reflux, altered testicular blood flow, antisperm antibody formation, alterations in the hypothalamic-pituitary-gonadal axis, and oxidative stress. This conditions do not deteriorate only the spermatogenesis but may also lead to testicular atrophy resulting in decreased size of testicles.
Complete absence of sperm in the ejaculate of a man.
An eating disorder characterized by the maintenance of a body weight below average, fear of gaining weight, and a distorted body image.
In the case of cryptorchidism one or both testes are absent from the scrotum. It is is the most common etiologic factor of azoospermy in the adult.
A class of sexual disorders defined as the subjective lack of normal ejaculation.
The set of symptoms that result from two or more X chromosome in males.
A genetic condition where the primary symptom is a failure to start puberty or a failure to fully complete puberty.
Complete absence of sperm in the ejaculate due to testicular failure.
The male sex chromosomal disorder characterized by a spectrum of clinical presentations, ranging from ambiguous to normal male genitalia.
A medical term which describes a diminished functional activity of the gonads – the testes and ovaries.
Male diagnosis connected with male infertility characterised by the complete absence of semen.
A family of genetic disorders caused by missing gene(s) in the Y chromosome.
