Benign fibromas may, but need not be, removed. Removal is usually a brief outpatient procedure.

Most fibroadenomas are simply monitored. Some are treated by surgical excision. They are removed with a small margin of normal breast tissue if the preoperative clinical investigations are suggestive of the necessity of this procedure. A small amount of normal tissue must be removed in case the lesion turns out to be a phyllodes tumour on microscopic examination.

Because needle biopsy is often a reliable diagnostic investigation, some doctors may decide not to operate to remove the lesion, and instead opt for clinical follow-up to observe the lesion over time using clinical examination and mammography to determine the rate of growth, if any, of the lesion. A growth rate of less than sixteen percent per month in women under fifty years of age, and a growth rate of less than thirteen percent per month in women over fifty years of age have been published as safe growth rates for continued non-operative treatment and clinical observation.

Some fibroadenomas respond to treatment with ormeloxifene.

Fibroadenomas have not been shown to recur following complete excision or transform into phyllodes tumours following partial or incomplete excision.

Since Krukenberg tumors are secondary (metastatic), management might logically be driven by identifying and treating the primary cancer. The optimal treatment of Krukenberg tumors is unclear. The role of surgical resection has not been adequately addressed but if metastasis is limited to the ovaries, surgery may improve survival. The role of chemotherapy and/or radiotherapy is uncertain but may sometimes be beneficial.

Usually the lesion is surgically removed. Primarily, there is concern that the lesion identified in a patient could be cancerous, but there is also the risk of torsion, and possibly the development of symptoms. A stable lesion, however, could be clinically followed.

Therapy is based on staging and patient condition and utilizes one or more of the following approaches.

Surgery is the mainstay of therapy if feasible involving total abdominal hysterectomy with bilateral salpingo-oophorectomy. Other approaches include radiation therapy, chemotherapy, and hormonal therapy.

Prognosis is relatively poor.

The common treatment for phyllodes is wide local excision. Other than surgery, there is no cure for phyllodes, as chemotherapy and radiation therapy are not effective. The risk of developing local recurrence or metastases is related to the histologic grade, according to the above-named features. Despite wide excision, a very high percentage of surgeries yielded incomplete excision margins that required revision surgery. Radiation treatment after breast-conserving surgery with negative margins may significantly reduce the

local recurrence rate for borderline and malignant tumors. The authors of a 2012 study have derived a risk calculator for relapse risk of phyllodes tumors after surgery.

The usual treatment is surgery. The surgery usually is a fertility-sparing unilateral salpingo-oophorectomy. For malignant tumours, the surgery may be radical and usually is followed by adjuvant chemotherapy, sometimes by radiation therapy. In all cases, initial treatment is followed by surveillance. Because in many cases Sertoli–Leydig cell tumour does not produce elevated tumour markers, the focus of surveillance is on repeated physical examination and imaging. Given that many cases of Sertoli–Leydig cell tumor of the ovary are hereditary, referral to a clinical genetics service should be considered.

The prognosis is generally good as the tumour tends to grow slowly and usually is benign: 25% are malignant. For malignant tumours with undifferentiated histology, prognosis is poor.

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.

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.

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 treatment for hemangioblastoma is surgical excision of the tumor. Although usually straightforward to carry out, recurrence of the tumor or more tumors at a different site develop in approximately 20% of patients. Gamma Knife Radiosurgery as well as LINAC have also been employed to successfully treat recurrence and control tumor growth of cerebellar hemangioblastomas.

The usual chemotherapy regimen has limited efficacy in tumours of this type, although Imatinib has shown some promise. There is no current role for radiotherapy.

The usual treatment is surgery. The surgery for females usually is a fertility-sparing unilateral salpingo-oophorectomy. For malignant tumours, the surgery may be radical and usually is followed by adjuvant chemotherapy, sometimes by radiation therapy. In all cases, initial treatment is followed by surveillance. Because in many cases Leydig cell tumour does not produce elevated tumour markers, the focus of surveillance is on repeated physical examination and imaging.

In males, a radical inguinal orchiectomy is typically performed. However, testes-sparing surgery can be used to maintain fertility in children and young adults. This approach involves an inguinal or scrotal incision and ultrasound guidance if the tumour is non-palpable. This can be done because the tumour is typically unifocal, not associated with precancerous lesions, and is unlikely to recur.

The prognosis is generally good as the tumour tends to grow slowly and usually is benign: 10% are malignant. For malignant tumours with undifferentiated histology, prognosis is poor.

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.

The FDA has approved cryoablation of a fibroadenoma as a safe, effective and minimally-invasive alternative to open surgical removal in 2001. In the procedure, ultrasound imaging is used to guide a probe into the mass of breast tissue. Extremely cold temperatures are then used to destroy the abnormal cells, and over time the cells are reabsorbed into the body. The procedure can be performed as an outpatient surgery using local anesthesia only, and leaves substantially less scarring than open surgical procedures and no breast tissue deformation.

The American Society of Breast Surgeons recommends the following criteria to establish a patient as a candidate for cryoablation of a fibroadenoma:

1. The lesion must be sonographically visible.

2. The diagnosis of a fibroadenoma must be confirmed histologically.

3. The lesion should be less than 4 cm in diameter.

Standard treatment would include surgical exploration via laparotomy. Laparoscopy may be an option if the surgeon is particularly skilled in removing ovarian neoplasms via laparoscopy intact. If the diagnosis of gonadoblastoma is certain, a bilateral salpingo-oophorectomy (BSO) should be performed to remove both the primary tumor and the dysgenic contralateral ovary. If uninvolved, the uterus should be left intact. Modern reproductive endocrinology technology allows patients post BSO to achieve pregnancy via in-vitro fertilization (IVF) with a donor egg.

Wide, radical, complete surgical excision is the treatment of choice, with free surgical margins to achieve the best outcome and lowest chance of recurrence. Radiation is only used for palliation. In general, there is a good prognosis, although approximately 50% of patients die from disease within 3–10 years of presentation.

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.)

For more general information, see ovarian cancer.

For advanced cancer of this histology, the US National Cancer Institute recommends a method of chemotherapy that combines intravenous (IV) and intraperitoneal (IP) administration. Preferred chemotherapeutic agents include a platinum drug with a taxane.

Due to the difficulty in identifying the tumour using imaging techniques, an orchiectomy is often performed. The majority of sertoli cell tumours are benign, so this is sufficient. There is no documented benefit of chemotherapy or radiotherapy.

General treatment regimens have not changed much in the past 30 years, in part due to the lack of randomized clinical trials. Surgery is the treatment of choice if the tumor is determined to be resectable. Curettage is a commonly used technique. The situation is complicated in a patient with a pathological fracture. It may be best to immobilize the affected limb and wait for the fracture to heal before performing surgery.

Patients with tumors that are not amenable to surgery are treated with radiation therapy. However caution is employed since a majority of recurrent tumors with transformations to the malignant sarcoma phenotype have been in patients receiving radiotherapy for their primary benign lesion. Pharmacotherapy for GCTOB, includes bisphosphonates such as Zoledronate, which are thought to induce apoptosis in the MNGC fraction, preventing tumor-induced osteolysis. Indeed, "in vitro" studies have shown zolidronate to be effective in killing osteoclast-like cells. More recently, humanized monoclonal antibodies such as Denosumab targeting the RANK ligand have been employed in treatment of GCTOB in a phase II study. This is based on the notion that increased expression of RANK-ligands by stromal cells plays a role in tumor pathogenesis.

In localized, resectable adult GISTs, if anatomically and physiologically feasible, surgery is the primary treatment of choice. Surgery can be potentially curative, but watchful waiting may be considered in small tumors in carefully selected situations. Post-surgical adjuvant treatment may be recommended. Lymph node metastases are rare, and routine removal of lymph nodes is typically not necessary. Laparoscopic surgery, a minimally invasive abdominal surgery using telescopes and specialized instruments, has been shown to be effective for removal of these tumors without needing large incisions. The clinical issues of exact surgical indications for tumor size are controversial. The decision of appropriate laparoscopic surgery is affected by tumor size, location, and growth pattern.

Radiotherapy has not historically been effective for GISTs and GISTs do not respond to most chemotherapy medications, with responses in less than 5%. However, three medications have been identified for clinical benefit in GIST: imatinib, sunitinib, and regorafenib.

Imatinib (Glivec/Gleevec), an orally administered drug initially marketed for chronic myelogenous leukemia based on bcr-abl inhibition, also inhibits both "c-kit" tyrosine kinase mutations and PDGFRA mutations other than D842V, is useful in treating GISTs in several situations. Imatinib has been used in selected neoadjuvant settings. In the adjuvant treatment setting, the majority of GIST tumors are cured by surgery, and do not need adjuvant therapy. However, a substantial proportion of GIST tumors have a high risk of recurrence as estimated by a number of validated risk stratification schemes, and can be considered for adjuvant therapy. The selection criteria underpinning the decision for possible use of imatinib in these settings include a risk assessment based on pathological factors such as tumor size, mitotic rate, and location can be used to predict the risk of recurrence in GIST patients. Tumors <2 cm with a mitotic rate of <5/50 HPF have been shown to have lower risk of recurrence than larger or more aggressive tumors. Following surgical resection of GISTs, adjuvant treatment with imatinib reduces the risk of disease recurrence in higher risk groups. In selected higher risk adjuvant situations, imatinib is recommended for 3 years.

Imatinib was approved for metastatic and unresectable GIST by the US FDA, February 1, 2002. The two-year survival of patients with advanced disease has risen to 75–80% following imatinib treatment.

If resistance to imatinib is encountered, the multiple tyrosine kinase inhibitor sunitinib (marketed as Sutent) can be considered.

The effectiveness of imatinib and sunitinib depend on the genotype. cKIT- and PDGFRA-mutation negative GIST tumors are usually resistant to treatment with imatinib as is neurofibromatosis-1-associated wild-type GIST. A specific subtype of PDGFRA-mutation, D842V, is also insensitive to imatinib.

Regorafenib (Stivarga) was FDA approved in 2013 for advanced GISTs that cannot be surgically removed and that no longer respond to imatinib (Gleevec) and sunitinib (Sutent).

Dysgerminomas are most effectively treated with radiation, though this can cause infertility and is being phased out in favor of chemotherapy. Radiation therapy does not improve survival in people with well-differentiated tumors.

In stage 1c and 2 cancers, radiation therapy is used after surgery if there is the possibility of residual disease in the pelvis but the abdomen is cancer-free. Radiotherapy can also be used in palliative care of advanced cancers. A typical course of radiotherapy for ovarian cancer is 5 days a week for 3–4 weeks. Common side effects of radiotherapy include diarrhea, constipation, and frequent urination.

There are a number of possible additional therapies. Surgery can be followed by radiation therapy and/or chemotherapy in cases of high-risk or high-grade cancers. This is called adjuvant therapy.

Adjuvant chemotherapy is a recent innovation, consisting of some combination of paclitaxel (or other taxanes like docetaxel), doxorubicin (and other anthracyclines), and platins (particularly cisplatin and carboplatin). Adjuvant chemotherapy has been found to increase survival in stage III and IV cancer more than added radiotherapy. Mutations in mismatch repair genes, like those found in Lynch syndrome, can lead to resistance against platins, meaning that chemotherapy with platins is ineffective in people with these mutations. Side effects of chemotherapy are common. These include hair loss, low neutrophil levels in the blood, and gastrointestinal problems.

In cases where surgery is not indicated, palliative chemotherapy is an option; higher-dose chemotherapy is associated with longer survival. Palliative chemotherapy, particularly using capecitabine and gemcitabine, is also often used to treat recurrent endometrial cancer.

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