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 standard of care for mucinous adenocarcinoma with clinical condition PMP involves cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC), by surgical oncologists who specialize in treating PMP. Some surgeons also apply early post-operative intraperitonial chemotherapy (EPIC), adjunct to surgical cytoreduction and HIPEC. In situations where surgery is not required immediately, patients can be monitored via CT scans, tumor marker laboratory tests, and physical symptoms, to determine when, and if, surgery is warranted. Although some surgical procedures may be rather extensive, patients can and do recover from surgery, and the majority of these patients can and do live productive lives.

In debulking, the surgeon attempts to remove as much tumor as possible. CRS or cytoreductive surgery involves surgical removal of the peritoneum and any adjacent organs which appear to have tumor seeding. Since the mucus tends to pool at the bottom of the abdominal cavity, it is common to remove the ovaries, fallopian tubes, uterus, and parts of the large intestine. Depending upon the spread of the tumor, other organs might be removed, including but not limited to the gallbladder, spleen, and portions of the small intestine and/or stomach. For organs that cannot be removed safely (like the liver), the surgeon strips off the tumor from the surface.

Treatment is variable, both due to its rarity and to its frequently slow-growing nature. Treatment ranges from watchful waiting to debulking and hyperthermic intraperitoneal chemotherapy (HIPEC, also called intraperitoneal hyperthermic chemotherapy, IPHC) with cytoreductive surgery.

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.

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.

Pain associated with ovarian cysts may be treated in several ways:

- Pain relievers such as acetaminophen, nonsteroidal anti-inflammatory drugs, or opioids.

- While hormonal birth control prevents the development of new cysts in those who frequently get them, it is not useful for the treatment of current cysts.

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.

Cysts can be removed by excision.

In case of fronto-ethmoidal epidermoid cysts, surgical resection appears to be the mainstay of treatment; however, the extent of resection is dictated by adherence of the tumor capsule to the surrounding vital structures.

Hydrogen peroxide gel (HO) was previously recommended for cyst treatment, particularly those on body piercings. However the gel cannot adequately permeate the cyst and was not found to be effective. Hydrogen peroxide is no longer recommended for wound care by doctors as it can damage the healing tissues.

On body piercings, self treatment with a hot saline soak to help drain the cyst and the use of an antibacterial or medicated talcum powder (Use of talc is no longer recommended due to recently discovered associations with multiple cancers.) to help dry out the bump and reduce bacterial proliferation is generally recommended until medical advice can be obtained. Piercings, however, are more likely to be victims of hypertrophic scarring than a cyst. Cheek piercings seem to be the piercing most prone to cysts due to the possible interruption of saliva ducts.

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.)

Treatment ranges from simple enucleation of the cyst to curettage to resection. For example, small radicular cyst may resolved after successful endodontic ("root-canal") treatment. Because of high recurrence potential and aggressive behaviour, curettage is recommended for keratocyst. However, the conservative enucleation is the treatment of choice for most odontogenic cysts. The removed cyst must be evaluated by pathologist to confirm the diagnosis, and to rule out other neoplastic lesions with similar clinical or radiographic features (e.g., cystic or solid ameloblastoma, central mucoepidermoid carcinoma). There are cysts, e.g. buccal bifurcation cyst with self-resolation nature, in which close observation can be employed unless the cyst is infected and symptomatic.

Surgical excision of a sebaceous cyst is a simple procedure to completely remove the sac and its contents.

There are three general approaches used: traditional wide excision, minimal excision, and punch biopsy excision.

The typical outpatient surgical procedure for cyst removal is to numb the area around the cyst with a local anaesthetic, then to use a scalpel to open the lesion with either a single cut down the center of the swelling, or an oval cut on both sides of the centerpoint. If the cyst is small, it may be lanced instead. The person performing the surgery will squeeze out the keratin surrounding the cyst, then use blunt-headed scissors or another instrument to hold the incision wide open while using fingers or forceps to try to remove the cyst intact. If the cyst can be removed in one piece, the "cure rate" is 100%. If, however, it is fragmented and cannot be entirely recovered, the operator may use curettage (scraping) to remove the remaining exposed fragments, then burn them with an electro-cauterization tool, in an effort to destroy them in place. In such cases the cyst may recur. In either case, the incision is then disinfected and, if necessary, the skin is stitched back together over it. A scar will most likely result.

An infected cyst may require oral antibiotics or other treatment before or after excision. If pus has already formed then incision and drainage should be done along with avulsion of cyst wall with proper antibiotics coverage.

An approach involving incision, rather than excision, has also been proposed.

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.

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.

Variants with edema can be associated with Meigs' syndrome. They may be a part of nevoid basal cell carcinoma syndrome (Gorlin syndrome).

A neurosurgeon performs a same day surgery to insert an endoscope, which drains the cyst internally.

Although most cases of ovarian cysts involve monitoring, some cases require surgery. This may involve removing the cyst, or one or both ovaries. Technique is typically laparoscopic, unless the cyst is particularly large, or if pre-operative imaging suggests malignancy or complex anatomy. In certain situations, the cyst is entirely removed, while with cysts with low recurrence risk, younger patients, or which are in anatomically eloquent areas of the pelvis, they can be drained. Features that may indicate the need for surgery include:

- Persistent complex ovarian cysts

- Persistent cysts that are causing symptoms

- Complex ovarian cysts larger than 5 cm

- Simple ovarian cysts larger 10 cm or larger than 5 cm in postmenopausal patients

- Women who are menopausal or perimenopausal

When treatment is required, this is usually by surgical removal of the cyst. There are four ways in which cysts are managed:

- Enucleation - removal of the entire cyst

- Marsupialization - the creation of a window into the wall of a cyst, allowing the contents to be drained. The window is left open, and the lack of pressure within the cyst causes the lesion to shrink, as the surrounding bone starts to fill in again.

- Enucleation following marsupialization - Sometimes marsupialization is carried out as a single procedure, but usually it is followed by a second procedure to remove the cyst. This is particularly the case when cysts are very large and their removal would leave a significant surgical defect.

- Enucleation with curettage - this is removal of the cyst and some of the surrounding bone, which may contain some of the lining of the cyst.

Treatment is often largely dependent on the type of cyst. Asymptomatic cysts, termed pseudocysts, normally require active monitoring with periodic scans for future growth. Symptomatic (producing or showing symptoms) cysts may require surgical removal if they are present in areas where brain damage is unavoidable, or if they produce chronic symptoms disruptive to the quality of life of the patient. Some examples of cyst removal procedures include: permanent drainage, fenestration, and endoscopic cyst fenestration.

Fertility subsequent to treatment of surface epithelial-stromal tumors depends mainly on histology and initial

staging to separate it into early borderline (or more benign) versus advanced stages of borderline (or more malignant). Conservative management (without bilateral oophorectomy) of early stage borderline tumors have been estimated to result in chance of over 50% of spontaneous pregnancy with a low risk of lethal recurrence of the tumor (0.5%). On the other hand, in cases of conservative treatment in advanced stage borderline tumors, spontaneous pregnancy rates have been estimated to be 35% and the risk of lethal recurrence 2%.

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

Sebaceous cysts generally do not require medical treatment. However, if they continue to grow, they may become unsightly, painful, infected, or all of the above.

Treatment ranges from simple enucleation of the cyst to curettage to resection. There are cysts—e.g., buccal bifurcation cyst—that resolve on their own, in which just close observation may be employed, unless it is infected and symptomatic.

Ocular oncology is the branch of medicine dealing with tumors relating to the eye and its adnexa.

Ocular oncology takes into consideration that the primary requirement for patients is preservation of life by removal of the tumor, along with best efforts directed at preservation of useful vision, followed by cosmetic appearance. The treatment of ocular tumors is generally a multi-specialty effort, requiring coordination between the ophthalmologist, medical oncologist, radiation specialist, head & neck surgeon/ENT surgeon, pediatrician/internal medicine/hospitalist and a multidisciplinary team of support staff and nurses.

The management of PASH is controversial. Excision may be indicated in enlarging masses or lesions with atypical features.