Why does germ cell tumour cause testicular lump?

The testicles contain germ cells, which are involved in sperm production. A germ cell tumour begins when some of these cells grow in an uncontrolled way and create a solid area within the testicle. The change may feel as a painless lump, diffuse firmness, enlargement or a heavy sensation in the scrotum. Some people notice discomfort, but pain is not required. Other causes of a testicular lump include infection, fluid, cysts or injury, so touch alone cannot tell which explanation applies.

Have any new testicular lump, firmness or change in size assessed promptly, even if it does not hurt. A clinician will examine both testicles and may arrange an ultrasound to distinguish a change inside the testicle from one beside it. Blood tests may check tumour markers, while the history helps identify infection or injury. Do not delay because the lump is painless, and avoid repeated forceful examination. Note when you first noticed the change and whether its size or heaviness has altered.

Seek emergency care for sudden severe testicular pain, rapid swelling, nausea or vomiting, because twisting of the testicle can threaten its blood supply. Arrange prompt medical review for a persistent lump, increasing size, new heaviness, or a change in the normal outline. Sudden pain and a painless lump are different situations, but neither should be ignored.

Is the change inside the testicle or in nearby tissue? Do I need an ultrasound or blood tests? What symptoms would require emergency care? If a germ cell tumour is suspected, what are the next diagnostic and treatment discussions?