Structural Biochemistry/Germ Cell Tumor

Definition
A germ cell tumor is characterized by the abnormal increase of germ cells, also known as a neoplasm of germ cells. Typically, germ cells are found within the gonads. When germ cell tumors originate outside of the gonads, it is usually due to birth defects, which results from errors from embryo development.

Classification
The germ cell tumor is usually classified by its histology, and is split into two classes:
 * Germinomatous germ cell tumors (GGCT), also known as seminomatous germ cell tumors (SGCT) include mainly germinoma, dysgerminoma, and seminoma. The survival rate of the GGCT tend to be higher due to the fact that they are sensitive to radiation and chemotherapy.
 * Nongerminomatous germ cell tumors (NGGCT), also known as nonseminomatous germ cell tumors (NSGCT) include the other germ cell tumors that can either be pure or mixed. Nongerminomatous tumors develop faster than germinomatous tumors and have an earlier mean age at the time of diagnosis. Individuals affected by NGGCTs have an average of 5 year survival rate.

Signs and Symptoms
Germ cell tumors typically vary in symptoms depending on their type and location

=Gonadal Tumors=


 * Ovarian: Ovarian germ cell tumors are hard to detect and typically grows to a relatively large size before symptoms can be seen. Swelling in the abdomen is a possible sign in the later stages of this cancer.
 * Testicular: Testicular tumors can be detected during the early stages due to the fact that they are noticeable in the scrotum and can cause pain. [1]

=Extragonadal Tumors=


 * Mediastinum Tumors: Mediastinum tumors are located within the cavity that contains the heart, trachea, connective tissues, thymus, and large blood vessels. These tumors usually cause chest pain, coughing, fever, and breathing problems.
 * Presacral Tumors: Presacral tumors are located in areas above or on the dorsal side of the sacral bone of the hip. This type of germ cell tumor usually appears as a mass in the lower abdomen of a child. It can cause difficulty in passing urine or enabling bowel movement. In some cases, it can create difficulty in walking.
 * Pineal Gland Tumors: The pineal gland is a small-sized gland located in the middle of the brain, usually causing symptoms by pressing directly on parts of the brain or interfering with the normal flow of the fluids within it. Symptoms of this germ cell tumor include headache, nausea, vomiting, memory loss, lethargy, difficulty walking, an inability to look upward, double vision, and uncontrolled eye movements. [1]
 * Sacrococcygeal Tumors: Sacrococcygeal tumors are located near the tailbone or the distal end of the spinal column. It is the most common tumor affecting newborns, and can sometimes be visible from the outside of the body.

Treatment
A majority of patients diagnosed with a germ cell tumor is treated with combination chemotherapy for 3 cycles. The most frequently used chemotherapy regimen for germ cell tumors is known as PEB, and contains antineoplastic, etoposide, and bleomycin.

Women with germ cell tumors are usually cured through the process of oophorectomy or ovarian cystectomy. Staging surgery is usually done for those with epithelial ovarian cancer.