Testicular Enlargement

Testicle is paired male sexual organ that produces sperm and the male sex hormone testosterone. The testicles need a lower temperature to work correctly, and therefore they are stored relatively close to the body surface outside the abdominal cavity in the scrotum. The size of a testicle in a healthy adult man should be about 4-5 centimeters. Enlargement of the testicle means usually nothing serious, but it is necessary to check it out to exclude some serious diseases.


Testicular tumors

They are mentioned in the first place, not because they are most common cause, but because these have to be always excluded. Testicular tumors are probably the single most important cause of testicle enlargement. The change of testicle size is otherwise asymptomatic; there is no pain, no fever, etc. Testicular tumors are numerous and particular danger depends on specific type of the tumor. Testicular tumors are relatively common form of cancer in young men. Their prognosis is, however, relatively good with early detection and therapy. Treatment consists of surgical removal of the affected testicle that is in some cases added with chemotherapy.


Epididymis, is a gland located in the upper pole of the testicle. In contrast to testis, epididymis is more frequently affected by infections (epididymitis) and this is probably the most common cause of testicular enlargement. This condition is often a complication of sexually transmitted diseases like gonorrhea or Chlamydia. Change of size is caused by swelling that is accompanied by redness of the scrotum and general symptoms of infection such as fever.

Testicular cysts

Cyst is a cavity whose wall is formed by the tissue from which cyst develops. Testicular cysts are usually quite harmless. They do no hurt and they are often filled with fluid. Due to painless testicular enlargement it is necessary to perform ultrasound examination to exclude the presence of a testicular tumor.

Hydrocele testis

This term means a simple collection of fluid around the testicle its surrounding layers. The reason of fluid formation may be associated with local inflammation, allergic reactions or mechanical damage done to the testicles. It is usually nothing serious, the fluid gradually absorbs. In case of excessive fluid accumulation, it can be evacuated by a simple surgical intervention.


This disorder is associated with dilation of veins that transport blood from the testicle into abdominal veins. Venous blood begins to accumulate in the testicle and this causes its enlargement. In addition to the enlarged testicle, bluish dilated veins are often visible under the skin of scrotum. Prolonged varicocele can cause irreversible loss of testicular function. Diagnosis can be done using ultrasound and treatment is performed either surgically or by embolization of the affected veins.

Testicular torsion

This emergency situation in urology is associated with rotation of the testis that causes constriction of blood vessels bringing oxygen and nutrients into the testicle. The main symptom of testicular torsion is severe shocking pain accompanied by redness and swelling of the scrotum. In addition to sudden onset of the pain, there are not usually present any general signs of infection.

Inflammation of the testicle

It is also known as orchitis and it is a relatively rare condition. Microorganisms do not usually attack testicular tissue. Mumps virus is the typical causative factor. It attacks testicles and causes painful inflammation that accompanies swollen parotid salivary glands. Mumps usually passes without complications, but there is, however, some risk of irreversible damage done to testicles causing infertility. Vaccination is associated with a sharp decline of the disease and its complications.

Scrotal abdominal hernia

This is not an enlargement of the testicle, but of scrotal sac. On first sight it may, however, imitate testicular enlargement. The abdominal cavity arches into scrotum as hernia sac covered with peritoneum (the lining membrane of the abdominal cavity). This hernia sac sometime contains a bowel loop. This condition is not painful (unless the hernia incarcerates), but despite that it should be solved. Sac of abdominal cavity located so close to testicles may cause their warming to intra-abdominal temperature and damage their sperm production.

Diagnostic approach

A urologist shall be familiarized with every case of enlarged testicle (or scrotum). The basis is, as always, medical history followed by physical examination. From imaging methods ultrasound is of a great importance that can diagnose the majority of local disorders. When there is uncertainty, doctors can perform fine needle biopsy to obtain a sample of tissue for histological examination (particularly valuable in cases of suspected tumor).

Jiri Stefanek, MD  Author of texts: Jiri Stefanek, MD
 Contact: jiri.stefanek@seznam.cz
 Sources: basic text sources