Testicular cancer can affect men of every age, across the world. But testicular cancer is not just one type of cancer. In fact, there are two main types of testicular cancer: germ cell tumors and stromal cell tumors. Each of these types also have subtypes. In addition, some of those subtypes have their own subtypes, leading to many different types of testicular cancer.

Testicular cancer is a type of cancer that happens in the testicles, or testes. These make male sex hormones and sperm. Testicles are located inside the scrotum, which is underneath the penis.

Testicular cancer is rare. However, it’s the most common cancer in males between ages 15 and 35. It’s a very treatable type of cancer and may be treated with surgery, chemotherapy, radiation therapy, or a combination of these treatments.

There are two main types of testicular cancer: germ cell tumors and stromal tumors. In addition, both types have subtypes.

Germ cell tumors

Overall, germ cell tumors are the most common type of testicular cancer, accounting for over 90 percent of testicular cancer. There are two main types of germ cell tumors, and you can have one type or a mixed type. Both types occur at about the same rate.

Seminoma germ cell tumors

One type is seminoma germ cell tumors, which grow and spread slowly in most cases. There are two types of seminoma germ cell tumors:

  • Classic seminoma, which account for 95 percent of seminoma germ cell tumors
  • Spermatocytic seminoma, which are more common in older men

Both types of seminoma cell tumors make a type of tumor marker called human chorionic gonadotropin, but no other types of tumor marker. Chemotherapy and/or radiation are usually the best treatments, especially if the cancer has spread, but surgery may also be possible.

Nonseminomatous germ cell tumors

The second type of germ cell tumor is nonseminomatous germ cell tumors. There are four main types, but most people will have more than one type:

  1. Embryonal carcinoma. A rapidly growing and aggressive tumor, which occurs in about 40 percent of nonseminomatous germ cell tumors.
  2. Yolk sac carcinoma. The most common type of testicular tumor in children, but it’s rare in adults. It responds well to chemotherapy.
  3. Choriocarcinoma. A very rare and aggressive type of tumor.
  4. Teratoma. Usually occurs in the mixed type of tumor. It’s usually local, but may spread to nearby lymph nodes. Teratomas are resistant to chemotherapy and radiation, and are best treated with surgery. There are three types of teratoma, including mature teratomas, immature teratomas, and teratomas with somatic type malignancy. This third type is very rare.

Stromal tumors

Stromal tumors make up less than 5 percent of testicular cancers. They develop in tissues around the germ (reproductive) cells in testicles. Most stromal tumors have a good prognosis after surgery.

There are two types of stromal tumors:

  • Leydig cell tumors, which make testosterone
  • Sertoli cell tumors, which are usually benign

Many symptoms of testicular cancer can also be caused by other conditions, such as an injury or certain infections. Therefore, if you have symptoms, it’s important to talk to your doctor to see if you can rule out any conditions.

Some men may not have symptoms of testicular cancer, even if the cancer starts to spread.

If you do have symptoms, they may include:

  • a lump in your testicle (usually the first symptom)
  • testicle swelling
  • a heavy feeling in your scrotum or lower abdomen
  • aching in your scrotum or lower abdomen
  • pain in your scrotum (not a common symptom)

There are also symptoms that may be a sign of certain types of testicular cancer. These symptoms are all rare and include:

Symptoms of advanced testicular cancer are dependent on where the cancer has spread:

A lump in your testicle is usually the first sign of testicular cancer. Some men discover the lump on their own, while others learn about it during a physical exam at their doctor’s office.

If you have a lump in your testicle, your doctor will do tests to figure out if the lump is cancer. First, they’ll do an ultrasound of your scrotum. This tells them whether the lump is solid or filled with fluid and whether it’s inside or outside the testicle itself.

Then they’ll likely do a blood test to look for tumor markers. These are substances in your blood that may increase if you have cancer.

If these tests indicate that you have cancer, your doctor may recommend surgery to remove your testicle. The testicle will be analyzed to see if it’s cancerous, and if so, what type of cancer you have.

If a cancer diagnosis is confirmed, you might need tests to figure out if the cancer has spread. These include:

  • CT scan in areas testicular cancer often spreads to, such as your pelvis, chest, or abdomen
  • blood tests to see if you still have elevated tumor markers after your testicle was removed

Treatment for testicular cancer depends on several factors, including what stage the cancer is in and your personal preferences, as some treatments can impact fertility.

The first line of treatment for all types of testicular cancer, regardless of type or stage, is removing the affected testicle. If your cancer hasn’t spread, this may be the only treatment you need. Your doctor may also remove nearby lymph nodes, if the cancer has spread there.

Radiation is sometimes used for seminoma type tumors. It uses high-powered beams of energy to kill cancer cells. These beams are targeted at specific areas of your body where there’s cancer. If used on your testicle, radiation therapy may impact fertility.

You may also have chemotherapy as your only treatment or after surgery if your cancer has spread. This type of treatment uses drugs to kill cancer cells throughout your body. Chemotherapy may also lead to infertility.

Testicular cancer is considered very treatable in most cases. For all men with testicular cancer, the cure rate is greater than 95 percent.

Even if the cancer has spread, there is an 80 percent overall cure rate. However, different metastase locations have different outlooks, especially in stromal tumors. In patients with stromal tumors, spread to the lung, liver, or bone leads to worse outcomes than spread to distant lymph nodes.

In patients with seminoma, only liver metastases lead to worse outcomes. For all types, the outlook is better if the cancer has only spread to one other area of the body.

Outlook may also depend on the type of testicular cancer. In stage one tumors, germ cell tumors have a better five-year survival rate than stromal tumors. The average cure rates are:

  • all germ cell tumors: 99.7 percent
  • leydig cell tumors: 91 percent
  • sertoli cell tumors: 77 percent