Germ cell tumor (GCT) is a
neoplasm
A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...
derived from
germ cell
Germ or germs may refer to:
Science
* Germ (microorganism), an informal word for a pathogen
* Germ cell, cell that gives rise to the gametes of an organism that reproduces sexually
* Germ layer, a primary layer of cells that forms during embry ...
s. Germ-cell tumors can be
cancer
Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...
ous or
benign
Malignancy () is the tendency of a medical condition to become progressively worse.
Malignancy is most familiar as a characterization of cancer. A ''malignant'' tumor contrasts with a non-cancerous benign tumor, ''benign'' tumor in that a malign ...
. Germ cells normally occur inside the
gonads
A gonad, sex gland, or reproductive gland is a mixed gland that produces the gametes and sex hormones of an organism. Female reproductive cells are egg cells, and male reproductive cells are sperm. The male gonad, the testicle, produces sperm ...
(
ovary
The ovary is an organ in the female reproductive system that produces an ovum. When released, this travels down the fallopian tube into the uterus, where it may become fertilized by a sperm. There is an ovary () found on each side of the body. ...
and
testis
A testicle or testis (plural testes) is the male reproductive gland or gonad in all bilaterians, including humans. It is homologous to the female ovary. The functions of the testes are to produce both sperm and androgens, primarily testostero ...
). GCTs that originate outside the gonads may be
birth defect
A birth defect, also known as a congenital disorder, is an abnormal condition that is present at birth regardless of its cause. Birth defects may result in disabilities that may be physical, intellectual, or developmental. The disabilities can ...
s resulting from errors during
development
Development or developing may refer to:
Arts
*Development hell, when a project is stuck in development
*Filmmaking, development phase, including finance and budgeting
*Development (music), the process thematic material is reshaped
*Photographi ...
of the
embryo
An embryo is an initial stage of development of a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male spe ...
.
Classification
GCTs are classified by their
histology
Histology,
also known as microscopic anatomy or microanatomy, is the branch of biology which studies the microscopic anatomy of biological tissues. Histology is the microscopic counterpart to gross anatomy, which looks at larger structures vis ...
,
regardless of location in the body. However, as more information about the genetics of these tumors become available, they may be classified based on specific gene mutations that characterize specific tumors. They are broadly divided in two classes:
* The germinomatous or seminomatous germ-cell tumors (GGCT, SGCT) include only
germinoma
A germinoma is a type of germ-cell tumor, which is not differentiated upon examination. It may be benign or malignant.
Cause
Germinomas are thought to originate from an error of development, when certain primordial germ cells fail to migrate pro ...
and its synonyms
dysgerminoma
A dysgerminoma is a type of germ cell tumor; it usually is malignant and usually occurs in the ovary.
A tumor of the identical histology but not occurring in the ovary may be described by an alternate name: seminoma in the testis or germinoma in ...
and
seminoma
A seminoma is a germ cell tumor of the testicle or, more rarely, the mediastinum or other extra-gonadal locations. It is a Malignancy, malignant neoplasm and is one of the most treatable and curable cancers, with a survival rate above 95% if dis ...
.
* The nongerminomatous or nonseminomatous germ-cell tumors (NGGCT, NSGCT) include all other germ-cell tumors, pure and mixed.
The two classes reflect an important clinical difference. Compared with germinomatous tumors, nongerminomatous tumors tend to grow faster, have an earlier mean age at time of diagnosis (around 25 years versus 35 years, in the case of
testicular cancer
Testicular cancer is cancer that develops in the testicles, a part of the male reproductive system. Symptoms may include a lump in the testicle, or swelling or pain in the scrotum. Treatment may result in infertility.
Risk factors include an u ...
s), and have a lower five-year survival rate. The survival rate for germinomatous tumors is higher in part because these tumors are very sensitive to radiation, and they also respond well to chemotherapy. The prognosis for nongerminomatous tumours has improved dramatically, however, due to the use of platinum-based chemotherapy regimens.
Germinomatous
Nongerminomatous
Mixed
Mixed germ cell tumors occur in many forms. Among these, a common form is teratoma with endodermal sinus tumor.
Teratocarcinoma refers to a germ cell tumor that is a mixture of
teratoma
A teratoma is a tumor made up of several different types of tissue, such as hair, muscle, teeth, or bone. Teratomata typically form in the ovary, testicle, or coccyx.
Symptoms
Symptoms may be minimal if the tumor is small. A testicular terato ...
with
embryonal carcinoma
Embryonal carcinoma is a relatively uncommon type of germ cell tumour that occurs in the ovaries and testes.
Signs and symptoms
The presenting features may be a palpable testicular mass or asymmetric testicular enlargement in some cases. The tum ...
, or with
choriocarcinoma
Choriocarcinoma is a malignant, trophoblastic cancer, usually of the placenta. It is characterized by early hematogenous spread to the lungs. It belongs to the malignant end of the spectrum in gestational trophoblastic disease (GTD). It is also cl ...
, or with both. This kind of mixed germ cell tumor may be known simply as a teratoma with elements of embryonal carcinoma or choriocarcinoma, or simply by ignoring the teratoma component and referring only to its malignant component: embryonal carcinoma and/or choriocarcinoma. They can present in the
anterior mediastinum
The mediastinum (from ) is the central compartment of the thoracic cavity. Surrounded by loose connective tissue, it is an undelineated region that contains a group of structures within the thorax, namely the heart and its vessels, the esophagu ...
.
Cause
Some investigators suggest that this distribution arises as a consequence of abnormal migration of germ cells during embryogenesis. Others hypothesize a widespread distribution of germ cells to multiple sites during normal embryogenesis, with these cells conveying genetic information or providing regulatory functions at somatic sites.
Extragonadal GCTs were thought initially to be isolated
metastases
Metastasis is a pathogenic agent's spread from an initial or primary site to a different or secondary site within the host's body; the term is typically used when referring to metastasis by a cancerous tumor. The newly pathological sites, then, ...
from an undetected primary tumor in a
gonad
A gonad, sex gland, or reproductive gland is a mixed gland that produces the gametes and sex hormones of an organism. Female reproductive cells are egg cells, and male reproductive cells are sperm. The male gonad, the testicle, produces sper ...
, but many germ cell tumors are now known to be
congenital
A birth defect, also known as a congenital disorder, is an abnormal condition that is present at birth regardless of its cause. Birth defects may result in disabilities that may be physical, intellectual, or developmental. The disabilities can ...
and originate outside the gonads. The most notable of these is
sacrococcygeal teratoma
Sacrococcygeal teratoma (SCT) is a type of tumor known as a teratoma that develops at the base of the coccyx (tailbone) and is thought to be primarily derived from remnants of the primitive streak. Sacrococcygeal teratomas are benign 75% of the ti ...
, the single most common tumor diagnosed in babies at birth.
Of all anterior mediastinal tumors, 15–20% are GCTs of which about 50% are benign teratomas. Ovarian teratomas may be associated with
anti-NMDA receptor encephalitis
Anti-NMDA receptor encephalitis is a type of encephalitis, brain inflammation caused by antibodies. Early symptoms may include fever, headache, and feeling tired. This is then typically followed by psychosis which presents with delusions, false b ...
.
Location
Despite their name, GCTs occur both within and outside the
ovary
The ovary is an organ in the female reproductive system that produces an ovum. When released, this travels down the fallopian tube into the uterus, where it may become fertilized by a sperm. There is an ovary () found on each side of the body. ...
and
testis
A testicle or testis (plural testes) is the male reproductive gland or gonad in all bilaterians, including humans. It is homologous to the female ovary. The functions of the testes are to produce both sperm and androgens, primarily testostero ...
. They are found in:}
*
head
A head is the part of an organism which usually includes the ears, brain, forehead, cheeks, chin, eyes, nose, and mouth, each of which aid in various sensory functions such as sight, hearing, smell, and taste. Some very simple animals may ...
** inside the
cranium
The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, the ...
—
pineal
The pineal gland, conarium, or epiphysis cerebri, is a small endocrine gland in the brain of most vertebrates. The pineal gland produces melatonin, a serotonin-derived hormone which modulates sleep patterns in both circadian and seasonal cycle ...
and
suprasellar
The sella turcica (Latin for 'Turkish saddle') is a saddle-shaped depression in the body of the sphenoid bone of the human skull and of the skulls of other hominids including chimpanzees, gorillas and orangutans. It serves as a cephalometric ana ...
locations are most commonly reported
** inside the
mouth
In animal anatomy, the mouth, also known as the oral cavity, or in Latin cavum oris, is the opening through which many animals take in food and issue vocal sounds. It is also the cavity lying at the upper end of the alimentary canal, bounded on ...
— a fairly common location for
teratoma
A teratoma is a tumor made up of several different types of tissue, such as hair, muscle, teeth, or bone. Teratomata typically form in the ovary, testicle, or coccyx.
Symptoms
Symptoms may be minimal if the tumor is small. A testicular terato ...
*
neck
The neck is the part of the body on many vertebrates that connects the head with the torso. The neck supports the weight of the head and protects the nerves that carry sensory and motor information from the brain down to the rest of the body. In ...
*
mediastinum
The mediastinum (from ) is the central compartment of the thoracic cavity. Surrounded by loose connective tissue, it is an undelineated region that contains a group of structures within the thorax, namely the heart and its vessels, the esophagu ...
— account for 1% to 5% of all germ cell neoplasms
*
pelvis
The pelvis (plural pelves or pelvises) is the lower part of the trunk, between the abdomen and the thighs (sometimes also called pelvic region), together with its embedded skeleton (sometimes also called bony pelvis, or pelvic skeleton).
The ...
, particularly
sacrococcygeal teratoma
Sacrococcygeal teratoma (SCT) is a type of tumor known as a teratoma that develops at the base of the coccyx (tailbone) and is thought to be primarily derived from remnants of the primitive streak. Sacrococcygeal teratomas are benign 75% of the ti ...
In females, GCTs account for 30% of ovarian tumors, but only 1 to 3% of
ovarian cancer
Ovarian cancer is a cancerous tumor of an ovary. It may originate from the ovary itself or more commonly from communicating nearby structures such as fallopian tubes or the inner lining of the abdomen. The ovary is made up of three different c ...
s in
North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...
. In younger women, they are more common, thus in patients under the age of 21, 60% of ovarian tumors are of the
germ-cell type, and up to one-third are
malignant
Malignancy () is the tendency of a medical condition to become progressively worse.
Malignancy is most familiar as a characterization of cancer. A ''malignant'' tumor contrasts with a non-cancerous ''benign'' tumor in that a malignancy is not s ...
. In males, GCTs of the testis occur typically after puberty and are malignant (
testicular cancer
Testicular cancer is cancer that develops in the testicles, a part of the male reproductive system. Symptoms may include a lump in the testicle, or swelling or pain in the scrotum. Treatment may result in infertility.
Risk factors include an u ...
). In
neonates
An infant or baby is the very young offspring of human beings. ''Infant'' (from the Latin word ''infans'', meaning 'unable to speak' or 'speechless') is a formal or specialised synonym for the common term ''baby''. The terms may also be used to ...
,
infants
An infant or baby is the very young offspring of human beings. ''Infant'' (from the Latin word ''infans'', meaning 'unable to speak' or 'speechless') is a formal or specialised synonym for the common term ''baby''. The terms may also be used to ...
, and
children
A child ( : children) is a human being between the stages of birth and puberty, or between the developmental period of infancy and puberty. The legal definition of ''child'' generally refers to a minor, otherwise known as a person younger ...
younger than 4 years, most are
sacrococcygeal teratoma
Sacrococcygeal teratoma (SCT) is a type of tumor known as a teratoma that develops at the base of the coccyx (tailbone) and is thought to be primarily derived from remnants of the primitive streak. Sacrococcygeal teratomas are benign 75% of the ti ...
s.
Males with
Klinefelter syndrome
Klinefelter syndrome (KS), also known as 47,XXY, is an aneuploid genetic condition where a male has an additional copy of the X chromosome. The primary features are infertility and small, poorly functioning testicles. Usually, symptoms are su ...
have a 50 times greater risk of GSTs.
In these persons, GSTs usually contain nonseminomatous elements, present at an earlier age, and seldom are gonadal in location.
Treatment
Women with benign GCTs such as
mature teratoma
A teratoma is a tumor made up of several different types of tissue, such as hair, muscle, teeth, or bone. Teratomata typically form in the ovary, testicle, or coccyx.
Symptoms
Symptoms may be minimal if the tumor is small. A testicular terato ...
s (dermoid cysts) are cured by
ovarian cystectomy
The ovary is an organ in the female reproductive system that produces an ovum. When released, this travels down the fallopian tube into the uterus, where it may become fertilized by a sperm. There is an ovary () found on each side of the body ...
or
oophorectomy
Oophorectomy (; from Greek , , 'egg-bearing' and , , 'a cutting out of'), historically also called ''ovariotomy'' is the surgical removal of an ovary or ovaries. The surgery is also called ovariectomy, but this term is mostly used in reference to ...
.
[ In general, all patients with malignant GCTs have the same staging surgery that is done for ]epithelial ovarian cancer
Surface epithelial-stromal tumors are a class of ovarian neoplasms that may be benign or malignant. Neoplasms in this group are thought to be derived from the ovarian surface epithelium (modified peritoneum) or from ectopic endometrial or Fallopi ...
. If the patient is in her reproductive years, an alternative is unilateral salpingoophorectomy
In medicine, salpingo-oophorectomy is the removal of an ovary and its Fallopian tube. This procedure is most frequently associated with prophylactic surgery in response to the discovery of a BRCA mutation, particularly those of the normally tumor ...
, while the uterus, the ovary, and the fallopian tube on the opposite side can be left behind. This is not an option when the cancer is in both ovaries. If the patient has finished having children, the surgery involves complete staging, including salpingoophorectomy on both sides, as well as hysterectomy
Hysterectomy is the surgical removal of the uterus. It may also involve removal of the cervix, ovaries (oophorectomy), Fallopian tubes (salpingectomy), and other surrounding structures.
Usually performed by a gynecologist, a hysterectomy may b ...
.[
Patients with germ-cell cancer often need to be treated with combination ]chemotherapy
Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs (chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemotherap ...
for at least three cycles, but female patients with early-stage disease may not require this treatment. The chemotherapy regimen
A chemotherapy regimen is a regimen for chemotherapy, defining the drugs to be used, their dosage, the frequency and duration of treatments, and other considerations. In modern oncology, many regimens combine several chemotherapy drugs in combinat ...
most commonly used in GCTs is called PEB (or BEP), and consists of bleomycin
-13- (1''H''-imidazol-5-yl)methyl9-hydroxy-5- 1''R'')-1-hydroxyethyl8,10-dimethyl-4,7,12,15-tetraoxo-3,6,11,14-tetraazapentadec-1-yl}-2,4'-bi-1,3-thiazol-4-yl)carbonyl]amino}propyl)(dimethyl)sulfonium
, chemical_formula =
, C=55 , H=84 , N=1 ...
, etoposide
Etoposide, sold under the brand name Vepesid among others, is a chemotherapy medication used for the treatments of a number of types of cancer including testicular cancer, lung cancer, lymphoma, leukemia, neuroblastoma, and ovarian cancer. It is ...
, and a platinum-based antineoplastic
Platinum-based antineoplastic drugs (informally called platins) are chemotherapeutic agents used to treat cancer. They are coordination complexes of platinum. These drugs are used to treat almost half of people receiving chemotherapy for cancer. ...
(cisplatin
Cisplatin is a chemotherapy medication used to treat a number of cancers. These include testicular cancer, ovarian cancer, cervical cancer, breast cancer, bladder cancer, head and neck cancer, esophageal cancer, lung cancer, mesothelioma, br ...
). Targeted treatments, such as immunotherapy, hormonal therapy and kinase inhibitors, are being evaluated for tumors that do not respond to chemotherapy.
Prognosis
The 1997 International Germ Cell Consensus Classification is a tool for estimating the risk of relapse after treatment of malignant germ-cell tumor.
A small study of ovarian tumors in girls reports a correlation between cyst
A cyst is a closed sac, having a distinct envelope and cell division, division compared with the nearby Biological tissue, tissue. Hence, it is a cluster of Cell (biology), cells that have grouped together to form a sac (like the manner in which ...
ic and benign tumors, and conversely, solid and malignant tumors. Because the cystic extent of a tumor can be estimated by ultrasound, MRI, or CT scan before surgery, this permits selection of the most appropriate surgical plan to minimize risk of spillage of a malignant tumor.
Access to appropriate treatment has a large effect on outcome. A 1993 study of outcomes in Scotland found that for 454 men with nonseminomatous (nongerminomatous) GCTs diagnosed between 1975 and 1989, five-year survival increased over time and with earlier diagnosis. Adjusting for these and other factors, survival was 60% higher for men treated in a cancer unit that treated the majority of these men, though the unit treated more men with the worst prognosis.
Choriocarcinoma
Choriocarcinoma is a malignant, trophoblastic cancer, usually of the placenta. It is characterized by early hematogenous spread to the lungs. It belongs to the malignant end of the spectrum in gestational trophoblastic disease (GTD). It is also cl ...
of the testicles has the worst prognosis of all germ-cell cancers.
See also
* Embryonic stem cells
Embryonic stem cells (ESCs) are pluripotent stem cells derived from the inner cell mass of a blastocyst, an early-stage pre- implantation embryo. Human embryos reach the blastocyst stage 4–5 days post fertilization, at which time they co ...
* Cancer research
Cancer research is research into cancer to identify causes and develop strategies for prevention, diagnosis, treatment, and cure.
Cancer research ranges from epidemiology, molecular bioscience to the performance of clinical trials to evaluate and ...
References
External links
* humpat
#2658
(Pathology images)
Childhood Extracranial Germ Cell Tumors
Extragonadal Germ Cell Tumors
Ovarian Germ Cell Tumors
*
Cancer.Net: Germ Cell Tumor
{{DEFAULTSORT:Germ Cell Tumor
Gynaecological cancer
Colorectal surgery
Male genital neoplasia
Germ cell neoplasia