For malignant teratomas, usually, surgery is followed by chemotherapy.

Teratomas that are in surgically inaccessible locations, or are very complex, or are likely to be malignant (due to late discovery and/or treatment) sometimes are treated first with chemotherapy.

The treatment of choice is complete surgical removal ("i.e.," complete resection). Teratomas are normally well-encapsulated and non-invasive of surrounding tissues, hence they are relatively easy to resect from surrounding tissues. Exceptions include teratomas in the brain, and very large, complex teratomas that have pushed into and become interlaced with adjacent muscles and other structures.

Prevention of recurrence does not require "en bloc" resection of surrounding tissues.

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.

Management of most fetal SCTs involves watchful waiting prior to any treatment. An often used decision tree is as follows:

- Perform detailed ultrasound exam including fetal echocardiogram and Doppler flow analysis

- If fetal high output failure, placentomegaly, or hydrops

- If fetus not mature, perform pregnancy termination or fetal intervention

- Else fetus mature, perform emergency Cesarean section

- Else no emergent problems, perform serial non-stress tests and ultrasound biophysical profiles and plan delivery, as follows

- If emergent problems develop, return to top of decision tree

- Else if SCT over 5–10 cm or polyhydramnios, perform early (37 weeks gestation) elective Cesarean section

- Else SCT small and no complications, permit term spontaneous vaginal delivery

Emergent problems include maternal mirror syndrome, polyhydramnios, and preterm labor. Poor management decisions, including interventions that are either premature or delayed, can have dire consequences. A very small retrospective study of 9 babies with SCTs greater than 10 cm diameter reported slightly higher survivorship in babies remaining in utero slightly longer.

In many cases, a fetus with a small SCT (under 5 or 10 cm) may be delivered vaginally. Prior to the advent of prenatal detection and hence scheduled C-section, 90% of babies diagnosed with SCT were born full term.

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

SCTs are very rare in adults, and as a rule these tumors are benign and have extremely low potential for malignancy. This estimation of potential is based on the idea that because the tumor existed for decades prior to diagnosis, without becoming malignant, it has little or no potential to ever become malignant. For this reason, and because coccygectomy in adults has greater risks than in babies, some surgeons prefer not to remove the coccyx of adult survivors of SCT. There are case reports of good outcomes.

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).

Treatment for dermoid cyst is complete surgical removal, preferably in one piece and without any spillage of cyst contents. Marsupialization, a surgical technique often used to treat pilonidal cyst, is inappropriate for dermoid cyst due to the risk of malignancy.

The association of dermoid cysts with pregnancy has been increasingly reported. They usually present the dilemma of weighing the risks of surgery and anesthesia versus the risks of untreated adnexal mass. Most references state that it is more feasible to treat bilateral dermoid cysts of the ovaries discovered during pregnancy if they grow beyond 6 cm in diameter.

Simple surgical excision is curative. The recommended treatment is that the skin is peeled off the extra-auricular tissue and protruding cartilage remnants are trimmed. Normal appearance is achieved in majority of cases. The reconstruction successful in true cases of accessory auricle, as it also is in individuals with auricular appendages.

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

Although surgery is the treatment of choice, it must be preceded by imaging studies to exclude an intracranial connection. Potential complications include meningitis and a cerebrospinal fluid leak. Recurrences or more correctly persistence may be seen in up to 30% of patients if not completely excised.

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.

The three basic types of treatment are surgery, radiation therapy, and chemotherapy.

Surgery is performed by urologists; radiation therapy is administered by radiation oncologists; and chemotherapy is the work of medical oncologists. In most patients with testicular cancer, the disease is cured readily with minimal long-term morbidity. While treatment success depends on the stage, the average survival rate after five years is around 95%, and stage 1 cancers cases, if monitored properly, have essentially a 100% survival rate.

Treatment for kidney cancer depends on the type and stage of the disease. Surgery is the most common treatment as kidney cancer does not often respond to chemotherapy and radiotherapy. Surgical complexity can be estimated by the RENAL Nephrometry Scoring System. If the cancer has not spread it will usually be removed by surgery. In some cases this involves removing the whole kidney however most tumors are amenable to partial removal to eradicate the tumor and preserve the remaining normal portion of the kidney. Surgery is not always possible – for example the patient may have other medical conditions that prevent it, or the cancer may have spread around the body and doctors may not be able to remove it. There is currently no evidence that body-wide medical therapy after surgery where there is no known residual disease, that is, adjuvant therapy, helps to improve survival in kidney cancer. If the cancer cannot be treated with surgery other techniques such as freezing the tumour or treating it with high temperatures may be used. However these are not yet used as standard treatments for kidney cancer.

Other treatment options include biological therapies such as everolimus, torisel, nexavar, sutent, and axitinib, the use of immunotherapy including interferon and interleukin-2. Immunotherapy is successful in 10 to 15% of people. Sunitinib is the current standard of care in the adjuvant setting along with pazopanib; these treatments are often followed by everolimus, axitinib, and sorafenib. Immune checkpoint inhibitors are also in trials for kidney cancer, and some have gained approval for medical use.

In the second line setting, nivolumab demonstrated an overall survival advantage in advanced clear renal cell carcinoma over everolimus in 2015 and was approved by the FDA. Cabozantinib also demonstrated an overall survival benefit over everolimus and was approved by the FDA as a second-line treatment in 2016. Lenvatinib in combination with everolimus was approved in 2016 for patients who have had exactly one prior line of angiogenic therapy.

In Wilms' tumor, chemotherapy, radiotherapy and surgery are the accepted treatments, depending on the stage of the disease when it is diagnosed.

The initial treatment for testicular cancer is surgery to remove the affected testicle (orchiectomy). While it may be possible, in some cases, to remove testicular cancer tumors from a testis while leaving the testis functional, this is almost never done, as the affected testicle usually contains pre-cancerous cells spread throughout the entire testicle. Thus removing the tumor alone without additional treatment greatly increases the risk that another cancer will form in that testicle.

Since only one testis is typically required to maintain fertility, hormone production, and other male functions, the afflicted testis is almost always removed completely in a procedure called inguinal orchiectomy. (The testicle is almost never removed through the scrotum; an incision is made beneath the belt line in the inguinal area.) In the UK, the procedure is known as a radical orchidectomy.

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.

A dermoid cyst is a teratoma of a cystic nature that contains an array of developmentally mature, solid tissues. It frequently consists of skin, hair follicles, and sweat glands, while other commonly found components include clumps of long hair, pockets of sebum, blood, fat, bone, nails, teeth, eyes, cartilage, and thyroid tissue.

As dermoid cysts grow slowly and contain mature tissue, this type of cystic teratoma is nearly always benign. In those rare cases wherein the dermoid cyst is malignant, a squamous cell carcinoma usually develops in adults, while infants and children usually present with an endodermal sinus tumor.

Treatment may include antibiotic therapy, hot compresses and application of depilatory creams. In more severe cases, the cyst may need to be lanced or treated surgically. Lancing is performed using a local anesthesia, with healing time generally under one week. The most conservative surgical treatment, Bascom's Pit Picking procedure, is a relatively simple outpatient option that can be performed in a physician's office, involves minimal pain and requires only a few days healing. Although this procedure is much less invasive than the alternatives, it is not regularly practiced in the US. The Pit Picking procedure provides good results, fast recovery, and in instances where it is unsuccessful, other options for more invasive surgery can still be performed.

The more common course for surgical treatment is for the cyst to be surgically excised (along with pilonidal sinus tracts). Post-surgical wound packing may be necessary, and packing typically must be replaced once daily for 4 to 8 weeks. In some cases, two years may be required for complete granulation to occur. Sometimes the cyst is resolved via surgical marsupialization.

Surgeons can also excise the sinus and repair with a reconstructive flap technique, such as a "cleft lift" procedure or Z-plasty, usually done under general anesthetic. This approach is especially useful for complicated or recurring pilonidal disease, leaves little scar tissue and flattens the region between the buttocks, reducing the risk of recurrence. This approach typically results in a more rapid recovery than the traditional surgery, however there are fewer surgeons trained in the cleft lift procedure and thus, it may not be as accessible to patients, depending on their geographic location. Meta analysis shows recurrence rates were lower in open healing than with primary closure (RR 0.60, 95% CI 0.42 to 0.87) at the expense of time to healing. Pilonidal cysts recur and do so more frequently if the surgical wound is sutured in the midline, as opposed to away from the midline, which obliterates the natal cleft and removes the focus of shearing stress. An incision lateral to the intergluteal cleft is therefore preferred, especially given the poor healing of midline incisions in this region.

An attractive minimally invasive technique is to treat pilonidal sinus with fibrin glue. This technique is less painful than traditional excisional techniques and flaps, can be performed under local or general anaesthesia, does not require dressings or packing and allows return to normal activities within 1 to 2 days. Long term outcome and recurrence rates are not dissimilar to more invasive techniques in 5 year follow up in a small randomised controlled trial.

Fibrin glue has also been shown to be better than more invasive alternatives in the treatment of pilonidal sinus disease in children, where a quick return to normal activities and minimal postoperative pain are especially important.

A minimally invasive surgical technique, was developed in Israel by Moshe Gips et al.,2008. and is similar to the pit picking technique first described by Bascom in 1980 In this procedure, trephines or biopsy punches which only "core out" and remove the diseased tissue and cyst are used, leaving only small holes to heal. Work or school activities will be resumed in one or two days, without or with minimal postoperative pain. The two procedures have been successfully combined by L. Basso in Rome (Italy).

While the recovery rate is positive for most, some suffer long term effects. Recorded instances include patients with continued postoperative pain for years following the surgical procedure. Primary complaints included pain when sitting for long period of times or following abrasive contact with the lower back and buttocks.

Treatment of Aicardi syndrome primarily involves management of seizures and early/continuing intervention programs for developmental delays.

Additional comorbidities and complications sometimes seen with Aicardi syndrome include porencephalic cysts and hydrocephalus, and gastro-intestinal problems. Treatment for porencephalic cysts and/or hydrocephalus is often via a shunt or endoscopic of the cysts, though some require no treatment. Placement of a feeding tube, fundoplication, and surgeries to correct hernias or other gastrointestinal structural problems are sometimes used to treat gastro-intestinal issues.

A struma ovarii (literally: goitre of the ovary) is a rare form of monodermal teratoma that contains mostly thyroid tissue, which may cause hyperthyroidism.

Despite its name, struma ovarii is not restricted to the ovary.

The vast majority of struma ovarii are benign tumors; however, malignant tumors of this type is found in a small percentage of cases.

Historically, the combination of external-beam radiation therapy (EBRT) has been the most common treatment for vaginal cancer. In early stages of vaginal cancer, surgery also has some benefit. This management and treatment is less effective for those with advanced stages of cancer but works well in early stages with high rates of cure. Advanced vaginal cancer only has a 5-year survival rates of 52.2%, 42.5% and 20.5% for patients with stage II, III and IVa disease. Newer treatments for advanced stages of ovarian have been developed. These utilize concurrent carboplatin plus paclitaxel, EBRT and high-dose-rate interstitial brachytherapy (HDR-ISBT).

When the chance of surgical removal of all cancerous tissue is very low or when the surgery has a chance of damaging the bladder, vagina or bowel, radiation therapy is used. When a tumor is less than 4 cm in diameter, radiation therapy provides excellent results. In these instances, the 5-year survival rate is greater than 80%. Treatments are individualized due to the rarity of vaginal cancer studies.

MEM comprises a heterogeneous group of neoplasms believed to originate from the neural crest. First hints to this type of tumor were probably from Shuangshoti and Nestky (1971) and from Holimon and Rosenblum (1971) (2-3). Additional contributions were provided thereafter by Naka et al. (1975), Karcioglu et al. (1977), Cozzutto et al. (1982) and Kawamoto et al. (1987).

Kosem et al. collected 44 cases of MEM in a 2004 review and examined management data finding out that resection with pre- or post-surgery chemotherapy yielded the best results with one death only in 13. In the five cases reported by Mouton et al. an aggressive chemotherapy and adequate surgical excision granted a disease-free interval for 7 to 50 months. The attainability of radical surgical

ablation seems the most important prognostic factor (10).

Embryonal tumor is a mass of rapidly growing cells. It is believed that it begins in embryonic (fetal) tissue. Embryonal tumors may be benign or malignant, and include neuroblastomas and Wilms tumors. Also called embryoma. Embryomas have been defined as: "Adult neoplasms expressing one or more embryo-exclusive genes", in: "Embryoma Gene Networks", http://www.embryomas.net

Embryomas can appear in the lungs.

It is not a precise term, and it is not commonly used in modern medical literature. Embryomas have been defined as: "Adult neoplasms expressing one or more embryo-exclusive genes".

If ovarian cancer recurs, it is considered partially platinum-sensitive or platinum-resistant, based on the time since the last recurrence treated with platins: partially platinum-sensitive cancers recurred 6–12 months after last treatment, and platinum-resistant cancers have an interval of less than 6 months. Second-line chemotherapy can be given after the cancer becomes symptomatic, because no difference in survival is seen between treating asymptomatic (elevated CA-125) and symptomatic recurrences.

For platinum-sensitive tumors, platins are the drugs of choice for second-line chemotherapy, in combination with other cytotoxic agents. Regimens include carboplatin combined with pegylated liposomal doxorubicin, gemcitabine, or paclitaxel. Carboplatin-doublet therapy can be combined with paclitaxel for increased efficacy in some cases. Another potential adjuvant therapy for platinum-sensitive recurrences is olaparib, which may improve progression-free survival but has not been shown to improve overall survival. (Olaparib, a PARP inhibitor, was approved by the US FDA for use in BRCA-associated ovarian cancer that had previously been treated with chemotherapy.) For recurrent germ cell tumors, an additional 4 cycles of BEP chemotherapy is the first-line treatment for those tho have been treated with surgery or platins.

If the tumor is determined to be platinum-resistant, vincristine, dactinomycin, and cyclophosphamide (VAC) or some combination of paclitaxel, gemcitabine, and oxaliplatin may be used as a second-line therapy.

For platinum-resistant tumors, there are no high-efficacy chemotherapy options. Single-drug regimens (doxorubicin or topotecan) do not have high response rates, but single-drug regimens of topotecan, pegylated liposomal doxorubicin, or gemcitabine are used in some cases. Topotecan cannot be used in people with an intestinal blockage. Paclitaxel used alone is another possible regimen, or it may be combined with liposomal doxorubicin, gemcitabine, cisplatin, topotecan, etoposide, or cyclophosphamide. ( See also Palliative care below.)

Chemotherapy and radiotherapy are effective in some tumors (such as Ewing's sarcoma) but less so in others (such as chondrosarcoma).

There is a variety of chemotherapy treatment protocols for bone tumors. The protocol with the best reported survival in children and adults is an intra-arterial protocol where tumor response is tracked by serial arteriogram. When tumor response has reached >90% necrosis surgical intervention is planned.