The testicles are male sex glands that produce sperm and the hormone testosterone. The testicles are two walnut-shaped glands inside the scrotum. The scrotum is the sac of skin that lies below the penis.
  Testicular cancer is a disease that occurs when cancerous (malignant) cells develop in the tissues of a testicle. The development of cancerous cells in both testicles can occur, but is very rare. 
Testicular cancer is the most common cancer in men aged 20 to 35. The disease usually is curable.
  Risk factors for developing testicular cancer include:

• Undescended testicle(s) — This is when one or both testicles do not move down into the scrotum before birth. 
• Klinefelter’s syndrome — This is a disorder in which males are born with an extra X chromosome in all or most of their cells. Certain other genetic syndromes are also associated with higher risk. 
• Race — Non-Hispanic, white men are more likely to develop this cancer than are men of other races and ethnicities. 
• Personal or family history — Men with a brother or father who had testis cancer have an increased risk of developing testis cancer themselves. Men who have had testis cancer themselves in one testicle are at increased risk of developing a second cancer in the other testicle. 

The following symptoms can be signs of testicular cancer or of another condition. Consult a doctor if you have any of these symptoms:

• Swelling in the scrotum 
• Lump or swelling in either testicle 
• Build-up of fluid on the scrotum 
• Dull ache in the groin or lower abdomen 
• Pain or discomfort in the scrotum or a testicle 

Testicular cancer is usually diagnosed after the man notices a lump or other change in a testicle. When an abnormality is suspected, an ultrasound is usually ordered, which is a painless medical test that helps the doctor to see whether there are abnormalities in the testicle. If the ultrasound shows evidence of cancer, then surgery is performed to remove the testicle and it is examined under a microscope to see whether cancer is present and, if so, what type of cancer. Thus, testicular cancer is only diagnosed after the testicle is removed and examined. Biopsies, which involve the removal of a small amount of tissue using a needle or other medical tool, are NOT performed on testicles because penetrating the testicle can make it more difficult to treat a cancer if one is discovered.

Tests to help diagnose testicular cancer can include:

• Ultrasound — This is a procedure that uses high-energy sound waves to form pictures of body tissues. 
• A physical exam and history — A physical exam and medical history can help the doctor look for problems that might be related to testicular cancer. 
• A serum tumor marker test — This procedure examines a blood sample to measure the amounts of certain substances linked to specific types of cancers. These substances are called tumor  markers. The tumor markers that are often elevated in testicular cancer are alpha-fetoprotein (AFP), human chorionic gonadotrophin (HCG or beta-HCG) and lactate dehydrongenase (LDH). 
• Inguinal orchiectomy and biopsy — This procedure involves the removal of the entire testicle through an incision in the groin. A tissue sample from the testicle is then checked for cancer cells. 
• CT scans and X-rays — A CT scan is a medical test that uses x-rays to form pictures of the inside of the body. When a cancer is diagnosed or suspected, a CT scan (also referred to as a CAT scan) is performed to see whether cancer can be seen elsewhere in the body. In testis cancer, a CT scan is performed of the abdomen and pelvis. Images of the chest are taken using either a CT scan or a regular X-ray. 

Stage 0 — Abnormal cells have developed but are still confined within the tubules where sperm cells start to develop.
Stage I - This stage consists of the stages IA, IB, and IS.
In Stage IA, the cancer is confined to the testicle and the epididymis, and all tumor marker levels are normal. The cancer has not spread to the outer layer of the double membrane that surrounds the testicle and has not grown into the blood or lymph vessels. 
In Stage IB, at least one of the following applies: The cancer invades into the blood vessels or lymphatics within the testicle; the cancer has spread to the outer layer of the membrane around the testicle; and/or the cancer invades into the spermatic cord or the scrotum. In stage IB, all tumor marker levels are normal. 
In Stage IS, the cancer is anywhere within the testicle, spermatic cord, or scrotum and one or more of the tumor markers is elevated. 
Stage II - This stage consists of Stage IIA, Stage IIB, and Stage IIC and refers to patients whose cancer has spread to the lymph nodes in the back of the abdomen (this part of the body is referred to as the retroperitoneum) but not to anywhere else. If patients with cancer in their lymph nodes have moderately or highly elevated tumor markers, then they are stage III rather than stage II.
In Stage IIA, the cancer has spread to a maximum of five lymph nodes in the abdomen. None of the lymph nodes is larger than 2 centimeters in size. Tumor markers must be either normal or only mildly elevated. 
In stage IIB, the cancer has spread to more than 5 nodes, none of which is larger than 5 centimeters, or the cancer has spread to 5 or fewer nodes and there is a lymph node mass measuring between 2 and 5 centimeters. Tumor markers must be either normal or mildly elevated. 
In Stage IIC, the cancer has spread to at least one lymph node in the abdomen that is larger than 5 cm diameter. Tumor markers must be either normal or only mildly elevated. 
Stage III - This stage is divided into Stage IIIA, Stage IIIB, and Stage IIIC and is determined after an inguinal orchiectomy (removal of a testicle through an incision in the groin) is performed.
In Stage IIIA, the cancer has spread to lymph nodes beyond the abdomen (such as lymph nodes in the chest) and/or to the lungs. Tumor markers must be normal or only mildly elevated. 
In stage IIIB, the cancer has spread to lymph nodes in the abdomen or elsewhere (such as lymph nodes in the chest) and/or to the lungs and the tumor markers are moderately elevated. 
In stage IIIC, either the cancer has spread to an organ other than the lungs (such as the liver, the bones, or the brain) or the tumor markers are highly elevated and the cancer has spread to at least one lymph node or organ. 
  Nearly all testicular cancers start in the germ cells (those that become sperm or eggs). The main types of testicular germ cell tumors are seminomas and non-seminomas. Non-seminomas tend to 
grow and spread faster than do seminomas. Seminomas are more sensitive to radiation, and both kinds are very sensitive to chemotherapy. If a testicular tumor has both seminoma and non-seminoma cells, it is treated as a non-seminoma.
  Surgical treatment - This treatment can include removing the testicle (orchiectomy) and removing associated lymph nodes (lymphadenectomy). Usually, orchiectomy is performed for both seminoma and non-seminoma testicular cancers, whereas lymph node removal is used only for non-seminomas. Surgery may also be performed in certain situations to remove tumors from the lungs or liver if they have not disappeared following chemotherapy. 
Radiation therapy - This treatment uses high-dose X-rays. Radiation might be used after surgery for patients with seminomas to prevent the tumor from returning. Usually, radiation is limited to the  treatment of seminomas. 
Chemotherapy - This treatment uses drugs such as cisplatin, bleomycin, and etoposide to kill cancer cells. Chemotherapy has improved the survival rate for people with both seminomas and non-seminomas. 
  In Stage I, the treatment is usually surgery to remove the testicle. For stage I seminomas, the standard treatment is observation, carboplatin chemotherapy, or radiation to the lymph nodes in the abdomen. For non-seminomas, management consists of observation, chemotherapy with bleomycin, etoposide, and cisplatin, or surgery to remove lymph nodes in the abdomen.
In Stage II, seminoma tumors are divided into bulky and non-bulky disease. Bulky disease is generally defined as tumors greater than 5 centimeters. For nonbulky disease, the treatment of stage II seminomas includes surgery to remove the testicle, followed by radiation to the lymph nodes or chemotherapy using nine weeks (three 21-day cycles) of bleomycin, etoposide, and cisplatin, or 12 weeks (four 21-day cycles) of etoposide and cisplatin. . In cases of bulky disease, the treatment involves surgery to remove the testicle, followed by chemotherapy using nine weeks (three 21-day cycles) of bleomycin, etoposide, and cisplatin, or 12 weeks (four 21-day cycles) of etoposide and cisplatin without bleomycin. 
The treatment of Stage II non-seminomas is similarly divided into bulky and nonbulky disease, but the cutoff is lower at 2 centimeters. For nonbulky disease, treatment is usually surgery to remove the testicle followed by either surveillance with CT scans or surgery to remove the lymph nodes in the back of the abdomen (the retroperitoneum). If cancer is found in the lymph nodes that are removed, then six weeks of chemotherapy using cisplatin and etoposide (either with or without bleomycin) is often recommended. For bulky disease, surgery is performed to remove the testicle, followed by chemotherapy (the same chemotherapy as defined above for seminoma). After chemotherapy, surgery should be performed to remove the lymph nodes in the back of the abdomen if there are any remaining enlarged nodes.
In Stage III, the treatment is surgery to remove the testicle followed by multi-drug chemotherapy. Treatment is the same for Stage III seminomas and non-seminomas, except that after chemotherapy,surgery is often performed to remove any residual tumors in non-seminomas. In seminomas, residual tumors usually do not require any additional treatment. Chemotherapy typically consists of nine weeks of bleomycin, etoposide, and cisplatin, or 12 weeks of etoposide plus cisplatin for patients with favorable risk factors and 12 weeks of bleomycin, etoposide, and cisplatin for patients with unfavorable risk factors. Unfavorable risk factors include highly elevated tumor markers in the blood and tumors in organs other than the lungs, such as the liver, bones, or brain.
If the cancer is a recurrence of a previous testicular cancer, the treatment usually consists of chemotherapy using combinations of different medicines, such as ifosfamide, cisplatin, etoposide, vinblastine, or paclitaxel. This treatment sometimes is followed by an autologous bone marrow or peripheral stem-cell transplant. Recurrences occurring more than two years after initial treatment are usually treated surgically.
  The prognosis is good for most men with testicular cancer. This form of cancer is treated successfully in more than 95 percent of cases. Even men with unfavorable risk factors have, on average, a 50 percent chance of being cured.
  There is no way to prevent testicular cancer, but early detection is important. Men should perform testicular self-examination (TSE) on a monthly basis. If you are a male over 15 years old who has 
not been informed about how to perform TSE, ask your doctor to show you how to do this. If a man notices any change in his testicles (lumps or nodules, hardness, persistent pain, or a testicle 
becoming bigger or smaller), he should notify his doctor right away so that the testicles can be evaluated.