An iris cyst, or uveal cyst, is a small hollow structure either attached to the iris of the eye or floating free in the anterior chamber. An iris cyst is composed of a single cell layer of epithelium and is filled with fluid. It is most commonly seen as secondary to inflammation in the eye, especially with canine glaucoma. They are most commonly seen in dogs. Golden Retrievers, Labrador Retrievers, and Boston Terriers are the most commonly affected breeds. Iris cysts also occur in cats and horses. The cysts are usually free floating in dogs, attached to the pupillary margin in cats, and present in the interior of the iris (especially blue irises) in horses.

Iris cysts usually cause no symptoms, but in large numbers they can cause glaucoma by obstructing the drainage angle of the eye. Golden Retrievers may have a higher rate of glaucoma associated with iris cysts.

Iris cysts need to be differentiated from iris melanoma, a tumor, by demonstrating their hollowness. A light directed at an iris cyst will cause it to transilluminate. Iris cysts can be collapsed if necessary by a veterinarian with a small needle carefully introduced into the anterior chamber. The cysts may also be destroyed by use of a semiconductor diode laser.

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.

A neurosurgeon may open a portion of the body and insert a shunt into cerebral spinal fluid (CSF) filled cysts to allow drainage into CSF pathways. The fluid from the cyst is then drained into the abdomen, the body reabsorbs the fluid (reabsorption of fluid does not cause any harm). This type of surgical treatment is often performed to relieve pressure on the brain from a cyst within the cerebral cortex.

Most arachnoid cysts are asymptomatic, and do not require treatment. Where complications are present, leaving arachnoid cysts untreated, may cause permanent severe neurological damage due to the progressive expansion of the cyst(s) or hemorrhage (bleeding). However, with treatment most individuals with symptomatic arachnoid cysts do well.

More specific prognoses are listed below:

- Patients with impaired preoperative cognition had postoperative improvement after surgical decompression of the cyst.

- Surgery can resolve psychiatric manifestations in selected cases.

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.

Most arachnoid cysts are asymptomatic and do not require treatment. Treatment may be necessary when symptomatic. A variety of procedures may be used to decompress (remove pressure from) the cyst.

- Surgical placement of a cerebral shunt:

- An internal shunt drains into the subdural compartment.

- A cystoperitoneal shunt drains to the peritoneal cavity.

- Craniotomy with excision

- Various endoscopic techniques are proving effective, including laser-assisted techniques.

- Drainage by needle aspiration or burr hole.

- Capsular resection

- Pharmacological treatments may address specific symptoms such as seizures or pain.

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.

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.

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.

Cutaneous columnar cysts are a cutaneous condition, a group of different cysts lined by columnar epithelium. Types of cysts included in this group are:

Various management options exist depending on the severity of symptoms and their effect on the patient. The main management options are: observation, craniotomy for microsurgical resection, neuroendoscopic removal, stereotactic drainage, and cerebrospinal fluid diversion with bilateral ventriculoperitoneal shunting placement.

Surgical excision is required to treat a trichilemmal cyst. The method of treatment varies depending on the physician's training. Most physicians perform the procedure under local anesthetic. Others prefer a more conservative approach. This involves the use of a small punch biopsy about 1/4 the diameter of the cyst. The punch biopsy is used to enter the cyst cavity. The content of the cyst is emptied, leaving an empty sac. As the pilar cyst wall is the thickest and most durable of the many varieties of cysts, it can be grabbed with forceps and pulled out of the small incision. This method is best performed on cysts larger than a pea which have formed a thick enough wall to be easily identified after the sac is emptied. Small cysts have walls that are thin, and easily fragmented on traction. This increases the likelihood of cyst recurrence. This method often results in only a small scar, and very little if any bleeding.

Conservative (i.e. no treatment), or surgical . With surgical excision, recurrence is common, usually due to incomplete excision. Often, the tracts of the cyst will pass near important structures, such as the internal jugular vein, carotid artery, or facial nerve, making complete excision impractical.

Because of the unclear pathogenesis and pathophysiology of Tarlov cysts, there is no consensus on the optimal treatment of symptomatic sacral perineural cysts. Patients often choose to pursue treatment when the progression of neurological deficits seriously impacts their quality of life.

Since cysts are innervated, microfenestration and surgical sleeving of the cysts to diminish the amount of accumulated cerebrospinal fluid and decrease compression of the spine and spinal nerves has been successful in a number of patients. The cysts are carefully separated enough from surrounding tissue to be wrapped with fatty tissue or pericardial biomaterial to excise the fluid from the cyst. If the cyst does not drain spontaneously, then it is drained and patched using a biosynthetic dural patch.

The use of this technique is done in the U.S. and is spreading in Europe but recovery is generally extensive. Microfenestration alone has been done with some success in Asia.

A biopolymer plate is also being used experimentally to strengthen a sacrum thinned by cystic erosion by Dr. Frank Feigenbaum.

The risks of CSF leakage are higher on patients that have bilateral cysts on the same spinal level or clusters of cysts along multiple vertebrae, but immediate recognition of the leakage and repair can mitigate that risk.

Various treatment methods have been tried in the past, including the extraction of cerebrospinal fluids from the cyst, fibrin glue injection and the complete or partial removal of cyst. Epidurals can provide temporary relief but are not generally recommended as they can cause cysts to enlarge. Extraction of fluid can provide limited or no relief depending on rate the cysts refill and the need to repeat the procedure. Removal of the cyst results in irreversible damage to the intersecting spinal nerve.

Although fibrin-glue therapy initially had been thought to be a promising therapy in the treatment of these cysts, there have been multiple problems associated with the fibrin glue therapy including seepage of fibrin. It is no longer recommended for use at present by the Health Department in some countries and neurosurgeons previously performing the procedures.

Nevertheless, all types of surgical treatment pose common risks, including neurological deficits, infection and inflammation, spinal headache, urinary disturbances, and leakage of cerebrospinal fluids.

Here is an article for treatment of meningeal diverticulum. Feigenbaum F1, Henderson FC. Giant sacral meningeal diverticula: surgical implications of the "thecal tip" sign. Report of two cases. J Neurosurg Spine. 2006 Nov;5(5):443-6.

In order to prevent further cysts and infections from forming, the thyroglossal duct and all of its branches are removed from the throat and neck area. A procedure, known as the Sistrunk procedure, is considered to be the standard procedure and involves removal of portions of the hyoid bone and core tissue of the suprahyoid region. Cysts will often reoccur if the entire duct is not removed, so reoccurrence requires a wider range of tissue to be removed in a subsequent surgery.

Delaying the surgical procedure almost always leads to recurrent infections, which will continue to delay the needed treatment. The Sistrunk procedure has a reoccurrence rate of less than 5%, proving it is extremely effective at removing the majority of traces of the persistent thyroglossal duct.

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.

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.

Besides the frequent choice to leave the cyst in place, surgical treatments remain the primary elective option for treatment of ganglion cysts. The progression of ganglion surgery worldwide is to use an arthroscopic or mini-opening method. Alternatively, a hypodermic needle may be used to drain the fluid from the cyst (via aspiration) and a corticosteroid may be injected after the cyst is empty; however, if the fluid has thickened, owing to the passage of time, this treatment is not always effective.

There is a recurrence rate of approximately 50% following needle drainage (via aspiration) of ganglion cysts.

One common and traditional method of treatment for a ganglion cyst was to strike the lump with a large and heavy book, causing the cyst to rupture and drain into the surrounding tissues. Historically, a Bible was the largest or only book in any given household, and was often employed for this treatment. This led to the former nickname of "Bible bumps" or "Gideon's disease" for these cysts. This treatment risks injuring the patient.

A Rathke's cleft cyst is a benign growth found on the pituitary gland in the brain, specifically a fluid-filled cyst in the posterior portion of the anterior pituitary gland. It occurs when the Rathke's pouch does not develop properly and ranges in size from 2 to 40mm in diameter.

Asymptomatic cysts are commonly detected during autopsies in 2 to 26 percent of individuals who have died of unrelated causes. Females are twice as likely as males to develop a cyst. If a cyst adds pressure to the optic chiasm, it may cause visual disturbances, pituitary dysfunction, and headaches. The majority of pituitary patients with chronic headaches have Rathke's Cleft Cysts. This is believed to be caused by the constant change in volume and the drastic changes in vasopressure from fluctuations in gonadotrophs and ADH.

The treatment of choice for symptomatic cysts is drainage and taking a biopsy. Radical excision is more dangerous because of the potential of damaging the patient's pituitary function e.g. ADH storage and lowering growth hormone production.

Genetic counseling is often recommended to provide more information about fetal CPCs, to answer questions and concerns, and to outline available options such as amniocentesis or a blood test from the mother. There is a possible association between ultrasound-detected fetal CPCs and Trisomy 18. It is not correlated to the presence of Trisomy 21 (Down syndrome).

Generally the risks are very low if there are no other risk factors. If no additional abnormalities are detected by a thorough "level II" ultrasound, the likelihood the fetus has trisomy 18 is very low.

A meta-analysis of 8 studies between 1990 and 2000 with choroid plexus cysts that were identified in second-trimester (an incidence of 1.2%). The incidence of the cysts in women younger than 35 was 1% (n=1017). The study found no cases of trisomy 18 in fetuses with cysts whose mother was younger than 35. The study concluded that "there is no evidence that detection of isolated choroid plexus cyst in women who are <35 years of age increases the risk of trisomy 18".

Other factors which may have a bearing on the baby's chances of developing chromosome problems include:

- mother's age at the expected date of delivery

- the results of serum screening; XAFP triple testing or quad screening

- evidence of other "fetal findings" seen at the time of the ultrasound that may suggest a chromosome problem

Recurrence rate is higher in aspirated cysts than in excised ones. Ganglion cysts have been found to recur following surgery in 12% to 41% of patients.

A six-year outcome study of the treatment of ganglion cysts on the dorsum (back) of the wrist compared excision, aspiration, and no treatment. Neither excision nor aspiration provided long-term benefit better than no treatment. Of the untreated ganglion cysts, 58% resolved spontaneously; the post-surgery recurrence rate in this study was 39%. A similar study in 2003 of ganglion cysts occurring on the palmar surface of the wrist states: "At 2 and 5 year follow-up, regardless of treatment, no difference in symptoms was found, regardless of whether the palmar wrist ganglion was excised, aspirated or left alone."

Choledochal cysts are treated by surgical excision of the cyst with the formation of a roux-en-Y anastomosis hepaticojujenostomy/ choledochojujenostomy to the biliary duct.

Future complications include cholangitis and a 2% risk of malignancy, which may develop in any part of the biliary tree. A recent article published in Journal of Surgery suggested that choledochal cysts could also be treated with single-incision laparoscopic hepaticojejunostomy with comparable results and less scarring. In cases of saccular type of cyst, excision and placement of T-shaped tube is done.

Currently, there is no accepted indication for fetal intervention in the management of prenatally suspected choledochal cysts.

PTCs originate from the mesothelium and are presumed to be remnants of the Müllerian duct and Wolffian duct.

Multiple studies have been found on how to remove a colloid cyst. One is an endoscopic removal. To remove the cyst, make a small incision. The endoscope is inserted into the brain and then moved toward the tumor in the ventricular compartment. The tumor is hit with an electric current. The interior of the cyst is removed followed by the cyst wall. The electric current is then used to kill the remaining pieces of the cyst. This whole process, including closing of the incision and removal of the scope is completed within 45 minutes to an hour. The patients are able to leave the hospital after 1 or 2 days. A case was done with the absence of ventriculomegaly that has been contraindication in an endoscopic removal. The study found that with normal-sized ventricles are not a contraindication. They actually have comparable or less complication rates. Another study experimented with a smaller retractor tube, 12 mm instead of 16–22 mm. The study found that using a 12 mm tube on a 10 mm colloid cyst. The surgery was successful in removing the cyst with a smaller retractor tube for resection while minimizing injury. The surgery had potential for improving outcomes.

Neuroendoscopic third ventriculostomy during surgery can be used to prevent further hydrocephalus post op. This removes the need for insertion of bilateral shunts.