| Germinoma | |
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| Micrograph of a germinoma, H&E stain | |
| Specialty | Oncology  |
A germinoma is a type of germ-cell tumor, [1] which is not differentiated upon examination. [2] It may be benign or malignant.
| Germinoma | |
|---|---|
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| Micrograph of a germinoma, H&E stain | |
| Specialty | Oncology |
A germinoma is a type of germ-cell tumor, [1] which is not differentiated upon examination. [2] It may be benign or malignant.
Germinomas are thought to originate from an error of development, when certain primordial germ cells fail to migrate properly. Germinomas lack histologic differentiation, whereas nongerminomatous germ-cell tumors display a variety of differentiation. Like other germ-cell tumors, germinomas can undergo malignant transformation.[ citation needed ]
The tumor is uniform in appearance, consisting of large, round cells with vesicular nuclei and clear or finely granular cytoplasm that is eosinophilic. On gross examination, the external surface is smooth and bosselated (knobby), and the interior is soft, fleshy, and either cream-coloured, gray, pink, or tan. Microscopic examination typically reveals uniform cells that resemble primordial germ cells. Typically, the stroma contains lymphocytes, and about 20% of patients have sarcoid-like granulomas.[ citation needed ]
Metastasis has been noted in about 22% of cases at time of diagnosis. Males are roughly twice as commonly affected in developing germinomas. They are most commonly diagnosed between the ages of 10 and 21.[ citation needed ]
Often, serum and spinal fluid tumor markers of alpha-fetoprotein and beta-HCG are tested. Pure germinomas are not associated with these markers. Nongerminomatous germ-cell tumors may be associated with increased markers such as alpha-fetoprotein with yolk sac tumors, as well as embryonic cell carcinomas and immature teratomas and beta-HCG, which occur in choriocarcinomas. In one to 15% of germinomas, a low level of beta-HCG may be produced. Although controversial, HCG-secreting germinomas may be more aggressive than nonsecreting ones.[ citation needed ]
The term "germinoma" most often refers to a tumor in the brain that has a histology identical to two other tumors, dysgerminoma in the ovary and seminoma in the testis. [3] Since 1994, MeSH has defined germinoma as "a malignant neoplasm of the germinal tissue of the gonads, mediastinum, or pineal region" [4] and within its scope included both dysgerminoma and seminoma. Collectively, these are the seminomatous or germinomatous tumors.[ citation needed ]
Dysgerminoma is the most common type of malignant germ-cell ovarian cancer. Dysgerminoma usually occurs in adolescence and early adult life; about 5% occur in prepubertal children. Dysgerminoma is extremely rare after age 50. It occurs in both ovaries in 10% of patients and, in a further 10%, a microscopic tumor is in the other ovary.[ citation needed ]
Seminoma is the second-most common testicular cancer; the most common is mixed, which may contain seminoma.[ citation needed ]
Abnormal gonads (due to gonadal dysgenesis and androgen insensitivity syndrome) have a high risk of developing a dysgerminoma. [5] Most dysgerminomas are associated with elevated serum lactic dehydrogenase, which is sometimes used as a tumor marker. Metastases are most often present in the lymph nodes.[ citation needed ]
Intracranial germinoma occurs in 0.7 per million children. [6] As with other germ-cell tumors (GCTs) occurring outside the gonads, the most common location of intracranial germinoma is on or near the midline, often in the pineal or suprasellar areas; in 5-10% of patients with germinoma in either area, the tumor is in both areas. Like other GCTs, germinomas can occur in other parts of the brain. Within the brain, this tumor is most common in the hypothalamic or hypophyseal regions. In the thalamus and basal ganglia, germinoma is the most common GCT.[ citation needed ]
The diagnosis of an intracranial germinoma usually is based on biopsy, as the features on neuroimaging appear similar to other tumors.[ citation needed ]
Cytology of the cerebrospinal fluid often is studied to detect metastasis into the spine. This is important for staging and radiotherapy planning.
Intracranial germinomas have a reported 90% survival to five years after diagnosis. [7] Near total resection does not seem to influence the cure rate, so gross total resection is not necessary and can increase the risk of complications from surgery. The best results have been reported[ citation needed ] from craniospinal radiation with local tumor boost of greater than 4,000 centigray (cGy).
Germinomas, like several other types of GCTs, are sensitive to both chemotherapy [8] and radiotherapy. For this reason, treatment with these methods can offer excellent chances of long-term survival, even cure.[ citation needed ]
Although chemotherapy can shrink germinomas, it is not generally recommended alone unless radiation has contraindications. In a study in the early 1990s, carboplatinum, etoposide, and bleomycin were given to 45 germinoma patients, and about half the patients relapsed. Most of these relapsed patients were then recovered with radiation or additional chemotherapy. [9]
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.
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.
Ovarian cancer is a cancer that forms in or on an ovary. It results in abnormal cells that have the ability to invade or spread to other parts of the body. When this process begins, there may be no or only vague symptoms. Symptoms become more noticeable as the cancer progresses. These symptoms may include bloating, pelvic pain, abdominal swelling, constipation, and loss of appetite, among others. Common areas to which the cancer may spread include the lining of the abdomen, lymph nodes, lungs, and liver.
An ependymoma is a tumor that arises from the ependyma, a tissue of the central nervous system. Usually, in pediatric cases the location is intracranial, while in adults it is spinal. The common location of intracranial ependymomas is the fourth ventricle. Rarely, ependymomas can occur in the pelvic cavity.
Sex cord–gonadal stromal tumour is a group of tumors derived from the stromal component of the ovary and testis, which comprises the granulosa, thecal cells and fibrocytes. In contrast, the epithelial cells originate from the outer epithelial lining surrounding the gonad while the germ cell tumors arise from the precursor cells of the gametes, hence the name germ cell. In humans, this group accounts for 8% of ovarian cancers and under 5% of testicular cancers. Their diagnosis is histological: only a biopsy of the tumour can make an exact diagnosis. They are often suspected of being malignant prior to operation, being solid ovarian tumours that tend to occur most commonly in post menopausal women.
A dysgerminoma is a type of germ cell tumor; it usually is malignant and usually occurs in the ovary.
Germ cell tumor (GCT) is a neoplasm derived from germ cells. Germ-cell tumors can be cancerous or benign. Germ cells normally occur inside the gonads. GCTs that originate outside the gonads may be birth defects resulting from errors during development of the embryo.
A seminoma is a germ cell tumor of the testicle or, more rarely, the mediastinum or other extra-gonadal locations. It is a malignant neoplasm and is one of the most treatable and curable cancers, with a survival rate above 95% if discovered in early stages.
Embryonal carcinoma is a relatively uncommon type of germ cell tumour that occurs in the ovaries and testes.
A pinealoma is a tumor of the pineal gland, a part of the brain that produces melatonin. If a pinealoma destroys the cells of the pineal gland in a child, it can cause precocious puberty.
Mediastinal germ cell tumors are tumors that derive from germ cell rest remnants in the mediastinum. They most commonly occur in the gonad but occasionally elsewhere.
An atypical teratoid rhabdoid tumor (AT/RT) is a rare tumor usually diagnosed in childhood. Although usually a brain tumor, AT/RT can occur anywhere in the central nervous system (CNS), including the spinal cord. About 60% will be in the posterior cranial fossa. One review estimated 52% in the posterior fossa, 39% are supratentorial primitive neuroectodermal tumors (sPNET), 5% are in the pineal, 2% are spinal, and 2% are multifocal.
A gonadoblastoma is a complex neoplasm composed of a mixture of gonadal elements, such as large primordial germ cells, immature Sertoli cells or granulosa cells of the sex cord, and gonadal stromal cells. Gonadoblastomas are by definition benign, but more than 50% have a co-existing dysgerminoma which is malignant, and an additional 10% have other more aggressive malignancies, and as such are often treated as malignant.
Ovarian diseases are conditions that happen to young women which can affect their reproductive system and general health.
Germ cell neoplasia in situ (GCNIS) represents the precursor lesion for many types of testicular germ cell tumors. As the name suggests, it represents a neoplastic process of germ cells that is confined to the spermatogonial niche.
Neuro-oncology is the study of brain and spinal cord neoplasms, many of which are very dangerous and life-threatening. Among the malignant brain cancers, gliomas of the brainstem and pons, glioblastoma multiforme, and high-grade astrocytoma are among the worst. In these cases, untreated survival usually amounts to only a few months, and survival with current radiation and chemotherapy treatments may extend that time from around a year to a year and a half, possibly two or more, depending on the patient's condition, immune function, treatments used, and the specific type of malignant brain neoplasm. Surgery may in some cases be curative, but, as a general rule, malignant brain cancers tend to regenerate and emerge from remission easily, especially highly malignant cases. In such cases, the goal is to excise as much of the mass and as much of the tumor margin as possible without endangering vital functions or other important cognitive abilities. The Journal of Neuro-Oncology is the longest continuously published journal in the field and serves as a leading reference to those practicing in the area of neuro-oncology.
Endodermal sinus tumor (EST) is a member of the germ cell tumor group of cancers. It is the most common testicular tumor in children under 3, and is also known as infantile embryonal carcinoma. This age group has a very good prognosis. In contrast to the pure form typical of infants, adult endodermal sinus tumors are often found in combination with other kinds of germ cell tumor, particularly teratoma and embryonal carcinoma. While pure teratoma is usually benign, endodermal sinus tumor is malignant.
Scrotalultrasound is a medical ultrasound examination of the scrotum. It is used in the evaluation of testicular pain, and can help identify solid masses.
An Extracranial Germ-Cell Tumor (EGCT) occurs in the abnormal growth of germ cells in the gonads and the areas other than the brain via tissue, lymphatic system, or circulatory system. The tumor can be benign or malignant (cancerous) by its growth rate. According to the National Cancer Institute and St. Jude Children's Research Hospital, the chance of children who are under 15 years old having EGCTs is 3%, in comparison to adolescents, a possibility of 14% with aged 15 to 19 can have EGCTs. There is no obvious cut point in between children and adolescents. However, common cut points in researches are 11 years old and 15 years old.
Ovarian germ cell tumors (OGCTs) are heterogeneous tumors that are derived from the primitive germ cells of the embryonic gonad, which accounts for about 2.6% of all ovarian malignancies. There are four main types of OGCTs, namely dysgerminomas, yolk sac tumor, teratoma, and choriocarcinoma.
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