Choriocarcinoma

Definition

A choriocarcinoma is type of cancer germ cell containing trophoblast cells.

Description

Choriocarcinomas are cancers that develop from germ cells, cells that ordinarily turn into sperm or eggs. Choriocarcinomas resemble the cells that surround an embryo in the uterus. Most of these cancers form inside the reproductive organs. Some originate in the testes or ovaries, especially in young adults. Others develop in the uterus after a pregnancy or miscarriage-particularly often after a mole. A few choriocarcinomas arise in sites outside the reproductive organs. Such "extragonadal" tumors are usually found in young adults and are more common in males.

Choriocarcinomas are one of the most dangerous germ cell cancers. Choriocarcinomas usually grow quickly and spread widely. Occasionally, this cancer grows so fast that the original tumor outgrows its blood supply and dies, leaving behind only a small scar.

Causes and symptoms

Choriocarcinomas result from genetic damage to a germ cell. Males with Klinefelter syndrome are especially likely to develop extragonadal germ cell tumors.

The symptoms of a choriocarcinoma vary, depending on where the tumor originates and where it spreads. In the uterus, the most common symptom is bleeding. Cancers in the ovary often have only subtle signs such as widening of the waistline or pain. In the testes, choriocarcinomas can often be felt as small painless lumps. Choriocarcinomas that spread to other organs may reveal their presence by bleeding. In the brain, this bleeding can cause a stroke.

Diagnosis

Choriocarcinomas are usually referred to an oncologist, a doctor who specializes in cancer treatment. To diagnose this tumor, the doctor will do a physical examination and examine the internal organs with x rays or ultrasound studies. Choriocarcinomas are not always biopsied before being treated, because they tend to bleed heavily. Spreading of the cancer is detected with x rays, ultrasound studies, computed tomography (CT), or magnetic resonance imaging (MRI) scans.

Most choriocarcinomas make human chorionic gonadotropin (hCG), a hormone normally found only during pregnancy. The presence of hCG in the blood can help diagnose this cancer and monitor the success of treatment.

Treatment

Choriocarcinomas are usually treated by surgical removal of the tumor and chemotherapy. Radiation is occasionally used, particularly for tumors in the brain.

Alternative treatment

Complementary treatments can decrease stress, reduce the side effects of cancer treatment, and help patients feel more in control. For instance, some people find activities such as yoga, massage, music therapy, meditation, prayer, or mild physical exercise helpful.

Prognosis

The prognosis for choriocarcinomas in the uterus is very good. Although these tumors have often spread throughout the body, chemotherapy results in a cure or remission in at least 80-90% of cases. Women who have had choriocarcinomas often go on to have normal pregnancies and deliveries.

Choriocarcinomas in other sites have a poorer prognosis. These tumors tend to spread quickly and don't always respond well to chemotherapy. Although treatment can be effective, the outcome usually depends on how widely the cancer is dispersed. Generally, the prognosis is worse if the cancer can be found in the liver or brain, if hCG levels are high, or if the original tumor developed outside the gonads. Five-year survival with testicular cancers can range from 92% for tumors that have spread only to the lungs to 48% to tumors that have spread to other internal organs.

Prevention

There is no known means of prevention. However, early detection of the symptoms and prompt medical treatment can improve the odds of survival.

Key Terms

Biopsy

A sample of an organ taken to look for abnormalities. Also, the technique used to take such samples.

Chemotherapy

The treatment of cancer with drugs.

Computed tomography (CT)

A special x ray technique that produces a cross sectional image of the organs inside the body.

Extragonadal

In a location other than the reproductive organs.

Germ cell

One of the cells that ordinarily develop into eggs or sperm (also sperm and eggs).

Gonads

The ovaries or testes.

Klinefelter syndrome

A condition caused by extra X chromosome(s) in a male, that results in small testes and infertility together with increased height, decreased facial hair, and sometimes breast enlargement.

Magnetic resonance imaging

A type of study that uses changes induced by magnets to see cells and tissues inside the body.

Mole

A mass of abnormal, partially developed tissues inside the uterus (womb). Moles develop during a pregnancy that begins with an abnormal fertilization.

Ovaries

The female sex organs that make eggs and female hormones.

Remission

The disappearance of the symptoms of cancer, although all of the cancer cells may not be gone.

Reproductive organs

The group of organs (including the testes, ovaries, and uterus) whose purpose is to produce a new individual and continue the species.

Testes

The male sex organs that make sperm and male hormones.

Testicular cancer

A cancer that originates in the testes.

Trophoblast

The tissues that surround an embryo and attach it to the uterus.

Tumor

A lump made up of abnormal cells.

Uterus

The organ where a child develops (womb).

For Your Information

Books

• Baker, Vicki V. "Gestational Trophoblastic Disease." In Clinical Oncology, 2nd ed. Ed. Martin D. Abeloff, et al. Philadelphia: Churchhill Livingstone, 2000.

• Crum, Christopher P. "The Female Genital Tract." In Robbins Pathologic Basis of Disease, 6th ed. Ed. Ramzi S. Cotran, Vinay Kumar, and Tucker Collins. Philadelphia: W.B. Saunders, 1999.

• Small, Eric J., and Frank M. Torti. "The Testes." In Clinical Oncology, 2nd ed. Ed. Martin D. Abeloff, et al. Philadelphia: Churchhill Livingstone, 2000.

• Smithson, William A. "Gonadal and Germ Cell Neoplasms." In Nelson Textbook of Pediatrics, 16th ed. Ed. Richard E. Behrman, et al. Philadelphia: W.B. Saunders, 2000.

• "The Male Genital Tract." In Robbins Pathologic Basis of Disease, 6th ed. Ed. Ramzi S. Cotran, Vinay Kumar, and Tucker Collins. Philadelphia: W.B. Saunders, 1999.

• Thigpen, James Tate. "Ovaries and Fallopian Tubes." In Clinical Oncology, 2nd ed. Ed. Martin D. Abeloff, et al. Philadelphia: Churchill Livingstone, 2000.

• Newlands, Edward S., Fernando J. Paradinas, and Rosemary A. Fisher. "Current Therapeutic Issues in Gynecologic Cancer. Recent Advances in Gestational Trophoblastic Disease." Hematology/Oncology Clinics of North America 13, no. 1 (Feb. 1999): 225-44.

• "Chemotherapy and You: A Guide to Self-help During Cancer Treatment." CancerNet. June 1999. 5 Apr. 2001 http://cancernet.nci.nih.gov/peb/chemo_you/index.htm

• "Extragonadal Germ Cell Tumors." CancerNet. http://cancernet.nci.nih.gov/pdq.html

• "Ovarian Germ Cell Tumor." CancerNet. Feb. 2001. 27 Apr. 2001 http://cancernet.nci.nih.gov/pdq.html

Sources: Gale Encyclopedia of Medicine, Published December, 2002 by the Gale Group

The Essay Author is Anna Rovid Spickler D.V.M., Ph.D..