A prospective study of ovarian sex cord–stromal tumours in children and adolescents began enrolling participants in 2005.

Spermatocytic seminomas are not considered a subtype of seminoma and unlike other germ cell tumours do not arise from intratubular germ cell neoplasia.

GCNIS is generally treated by radiation therapy and/or orchiectomy. Chemotherapy used for metastatic germ cell tumours may also eradicate GCNIS.

Women with benign germ cell tumors such as mature teratomas (dermoid cysts) are cured by ovarian cystectomy or oophorectomy. In general, all patients with malignant germ cell tumors will have the same staging surgery that is done for epithelial ovarian cancer. If the patient is in her reproductive years, an alternative is unilateral salpingoophorectomy, while the uterus, the ovary, and the fallopian tube on the opposite side can be left behind. This isn't 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.

Most patients with germ cell cancer will need to be treated with combination chemotherapy for at least 3 cycles. The chemotherapy regimen most commonly used in germ cell tumors is called PEB (or BEP), and consists of bleomycin, etoposide, a platinum-based antineoplastic (cisplatin).

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 cystic 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 non-seminomatous (non-germinomatous) germ cell tumors diagnosed between 1975 and 1989, 5-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, even though the unit treated more men with the worst prognosis.

Choriocarcinoma of the testicles has the worst prognosis of all germ cell cancers

Pure mediastinal seminomas are curable in the large majority of patients, even when metastatic at the time of diagnosis. These tumors are highly sensitive to radiation therapy and to combination chemotherapy. However, the cardiotoxicity of mediastinal radiation is substantial and the standard treatment of mediastinal seminomas is with chemotherapy using bleomycin, etoposide and cisplatin for either three or four 21-day treatment cycles depending on the location of any metastatic disease.

Patients with small tumors (usually asymptomatic) that appear resectable usually undergo thoracotomy and attempted complete resection followed by chemotherapy.

The treatment for mediastinal nonseminomatous germ cell tumors should follow guidelines for poor-prognosis testicular cancer. Initial treatment with four courses of bleomycin, etoposide, and cisplatin, followed by surgical resection of any residual disease, is considered standard therapy.

Germ cell neoplasia in situ, abbreviated 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.

The term GCNIS was introduced with the 2016 edition of the WHO classification of urological tumours. It replaces the previous term intratubular germ cell neoplasia, abbreviated ITGCN or IGCN and also known as testicular intratubular germ cell neoplasia and intratubular germ cell neoplasia of the testis. GCNIS more accurate describes the lesion as it arises between the basement membrane and Sertoli cells (the cells that 'nurse' the developing germ cell). The common, unspecified variant of the entity was once considered to be a carcinoma in situ although the term "carcinoma "in situ"" is now largely historical as it is not an accurate description of the process.

A retrospective study of 83 women with sex cord–stromal tumours (73 with granulosa cell tumour and 10 with Sertoli-Leydig cell tumour), all diagnosed between 1975 and 2003, reported that survival was higher with age under 50, smaller tumour size, and absence of residual disease. The study found no effect of chemotherapy. A retrospective study of 67 children and adolescents reported some benefit of cisplatin-based chemotherapy.

Unlike classical seminoma, spermatocytic seminomas rarely metastasise, so radical orchidectomy alone is sufficient treatment, and retroperitoneal lymph node dissection and adjuvant chemotherapy or radiotherapy are generally not required.

Malignant germ cell tumors of the mediastinum are uncommon, representing only 3 to 10% of tumors originating in the mediastinum. They are much less common than germ cell tumors arising in the testes, and account for only 1 to 5% of all germ cell neoplasms.

Syndromes associated with mediastinal germ cell tumors include Hematologic Neoplasia and Klinefelter's syndrome.

Dysgerminomas, like other seminomatous germ cell tumors, are very sensitive to both chemotherapy and radiotherapy. For this reason, with treatment patients' chances of long-term survival, even cure, is excellent.

Most treatments involve some combination of surgery and chemotherapy. Treatment with cisplatin, etoposide, and bleomycin has been described.

Before modern chemotherapy, this type of neoplasm was highly lethal, but the prognosis has significantly improved since.

When endodermal sinus tumors are treated promptly with surgery and chemotherapy, fatal outcomes are exceedingly rare.

Germinomas, like several other types of germ cell tumor, are sensitive to both chemotherapy and radiotherapy. For this reason, treatment with these methods can offer excellent chances of longterm survival, even cure.

Although chemotherapy can shrink germinomas, it is not generally recommended alone unless there are contraindications to radiation. 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.

Embryonal carcinoma is a relatively uncommon type of germ cell tumour that occurs in the ovaries and testes.

Spermatocytic seminoma is a neoplasm of the testis ("i.e." a tumour of the testis), and classified as a germ cell tumour.

The name of the tumour comes from the similarity (under the microscope) between the small cells of the tumour and secondary spermatocytes.

Intratesticular masses that appear suspicious on an ultrasound should be treated with an inguinal orchiectomy. The pathology of the removed testicle and spermatic cord indicate the presence of the seminoma and assist in the staging. Tumors with both seminoma and nonseminoma elements or that occur with the presence of AFP should be treated as nonseminomas. Abdominal CT or MRI scans as well as chest imaging are done to detect for metastasis. The analysis of tumor markers also helps in staging.

The preferred treatment for most forms of stage 1 seminoma is active surveillance. Stage 1 seminoma is characterized by the absence of clinical evidence of metastasis. Active surveillance consists of periodic history and physical examinations, tumor marker analysis, and radiographic imaging. Around 85-95% of these cases will require no further treatment. Modern radiotherapy techniques as well as one or two cycles of single-agent carboplatin have been shown to reduce the risk of relapse, but carry the potential of causing delayed side effects. Regardless of treatment strategy, stage 1 seminoma has nearly a 100% cure rate.

Stage 2 seminoma is indicated by the presence of retroperitoneal metastasis. Cases require radiotherapy or, in advanced cases, combination chemotherapy. Large residual masses found after chemotherapy may require surgical resection. Second-line treatment is the same as for nonseminomas.

Stage 3 seminoma is characterized by the presence of metastasis outside the retroperitoneum—the lungs in "good risk" cases or elsewhere in "intermediate risk" cases. This is treated with combination chemotherapy. Second-line treatment follows nonseminoma protocols.

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 the central nervous system or other parts of the body.

Dysgerminoma accounts for less than 1% of ovarian tumors overall. Dysgerminoma usually occurs in adolescence and early adult life; about 5% occur in pre-pubertal children. Dysgerminoma is extremely rare after age 50. Dysgerminoma occurs in both ovaries in 10% of patients and, in a further 10%, there is microscopic tumor in the other ovary.

Abnormal gonads (due to gonadal dysgenesis and androgen insensitivity syndrome) have a high risk of developing a dysgerminoma. Most dysgerminomas are associated with elevated serum lactic dehydrogenase (LDH), which is sometimes used as a tumor marker.

Because LCLC-RP is so rare, no clinical trials have ever been conducted that specifically address treatment of this lung cancer variant. Because LCLC-RP is considered a form of non-small cell lung carcinoma (NSCLC), most physicians adhere to published NSCLC treatment guidelines in rhabdoid carcinoma cases. When possible, radical surgical resection with curative intent is the primary treatment of choice in early stage NSCLC's, and can be administered with or without adjuvant, neoadjuvant, or palliative chemotherapy and/or radiotherapy, depending on the disease stage and performance status of the individual patient.

In numerous clinical trials conducted in NSCLC, several different platinum-based chemotherapy regimens have been shown to be more-or-less equally effective. LCLC's, as a subtype of NSCLC, have traditionally been included in many of these clinical trials, and have been treated like other NSCLC's. More recent trials, however, have shown that some newer agents may have particular effectiveness in prolonging survival of LCLC patients. Pemetrexed, in particular, has shown significant reduction in the hazard ratio for death when used in patients with LCLC. Taxane-based (paclitaxel, docetaxel) chemotherapy was shown to induce a complete and sustained response in a liver metastasis in a case of LCC-RP. A later-appearing metastasis within mediastinal lymph nodes in the same case also showed a durable response to a taxane alone.

There have also been reports of rhabdoid carcinomas expressing vascular endothelial growth factor (VEGF), suggesting that targeted molecular therapy with VEGF blocking monoclonal antibodies such as bevacizumab may be active in these variants. However, evidence suggests that caution must be used when treating a cavitated rhabdoid tumor, one that contains significant components of squamous cell differentiation, or large tumors with containing major blood vessels, due to the potential high risk of life-threatening pulmonary hemorrhage.

A recent study reported a case wherein 2 courses of adjuvant therapy with cisplatin and paclitaxel, followed by oral gefitinib, were used after complete resection. The patient had had no recurrence 34 months later.

As large-volume LCLC-RP may show significant central necrosis and cavitation, prudence dictates that oncologists use extreme caution if contemplating the therapeutic use of bevacizumab, other anti-VEGF compounds, or anti-angiogenesis agents in general, which have been associated with a greatly increased risk of severe hemorrhage and hemoptysis that may be quickly fatal in cavatated pulmonary squamous cell carcinomas. Similar elevated risks have also been noted in tumors located near, or containing, large blood vessels.,

An immature teratoma is a rare type of malignant (cancerous) germ cell tumor (type of tumor that begins in the cells that give rise to sperm or eggs).

Like a mature teratoma, it contains several different types of tissue such as hair, muscle, and bone. Unlike a mature teratoma, it contains primitive neuroepithelium.

Since gestational choriocarcinoma (which arises from a hydatidiform mole) contains paternal DNA (and thus paternal antigens), it is exquisitely sensitive to chemotherapy. The cure rate, even for metastatic gestational choriocarcinoma, is around 90–95%.

At present, treatment with single-agent methotrexate is recommended for low-risk disease, while intense combination regimens including EMACO (etoposide, methotrexate, actinomycin D, cyclosphosphamide and vincristine (Oncovin) are recommended for intermediate or high-risk disease.

Hysterectomy (surgical removal of the uterus) can also be offered to patients > 40 years of age or those for whom sterilisation is not an obstacle. It may be required for those with severe infection and uncontrolled bleeding.

Choriocarcinoma arising in the testicle is rare, malignant and highly resistant to chemotherapy. The same is true of choriocarcinoma arising in the ovary. Testicular choriocarcinoma has the worst prognosis of all germ-cell cancers.

Based on a survey of >800, surgical removal of the entire involved kidney plus the peri-renal fat appeared curative for the majority of all types of mesoblastic nephroma; the patient overall survival rate was 94%. Of the 4% of non-survivors, half were due to surgical or chemotherapeutic treatments. Another 4% of these patients suffered relapses, primarily in the local area of surgery rare cases of relapse due to lung or bone metastasis.. About 60% of these recurrent cases had a complete remission following further treatment. Recurrent disease was treated with a second surgery, radiation, and/or chemotherapy that often vincristine and actinomycin treatment. Removal of the entire afflicted kidney plus the peri-renal fat appears critical to avoiding local recurrences. In general, patients who were older than 3 months of age at diagnosis or had the cellular form of the disease, stage III disease, or involvement of renal lymph nodes had a higher recurrence rate. Among patients with these risk factors, only those with lymph node involvement are recommended for further therapy.

It has been suggested that mesoblastic nephroma patients with lymph node involvement or recurrent disease might benefit by adding the ALK inhibitor, crizotinib, or a tyrosine kinase inhibitor, either larotrectinib or entrectinib, to surgical, radiation, and/or chemotherapy treatment regimens. These drugs inhibit NTRK3's tyrosine kinase activity. Crizotinib has proven useful in treating certain cases of acute lymphoblastic leukemia that are associated with the "ETV6-NTRK3" fusion gene while larotrectinib and entrectinib have been useful in treating various cancers (e.g. a metastatic sarcoma, papillary thyroid cancer, non-small-cell lung carcinoma, gastrointestinal stromal tumor, mammary analog secretory carcinoma, and colorectal cancer) that are driven by mutated, overly active tyrosine kinases. Relevant to this issue, a 16-month-old girl with infantile fibrosarcoma harboring the "ETV6–NTRK3" fusion gene was successfully trated with larotrectinib. The success of these drugs, howwever, will likely depend on the relative malignancy-promoting roles of ETV6-NTRK3 protein's tyrosine kinase activity, the lose of ETV6-related transcription activity accompanying formation of ETV6-NTRK3 protein, and the various trisomy chromosomes that populate mesoblastic nephroma.

Polyembryoma is a rare, very aggressive form of germ cell tumor usually found in the ovaries. Polyembryoma has features of both yolk sac tumour and undifferentiated teratoma/embryonal carcinoma, with a characteristic finding of embryoid bodies lying in a loose mesenchymal stroma.

It has been found in association with Klinefelter syndrome.

Endodermal sinus tumor (EST), also known as yolk sac tumor (YST), 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.

Because of its rarity, there have been no randomized clinical trials of treatment of GCCL, and all information available derives from small retrospective institutional series or multicenter metadata.

The prognosis of patients with FA as a whole is considered to be better than that of most other forms of non-small cell carcinoma, including biphasic pulmonary blastoma.