These lesions rarely require surgery unless they are symptomatic or the diagnosis is in question. Since these lesions do not have malignant potential, long-term observation is unnecessary. Surgery can include the removal of the head of the pancreas (a pancreaticoduodenectomy), removal of the body and tail of the pancreas (a distal pancreatectomy), or rarely removal of the entire pancreas (a total pancreatectomy). In selected cases the surgery can be performed using minimally invasive techniques such as laparoscopy.

The treatment of choice for main-duct IPMNs is resection due to approximately 50% chance of malignancy. Side-branch IPMNs are occasionally monitored with regular CT or MRIs, but most are eventually resected, with a 30% rate of malignancy in these resected tumors. Survival 5 years after resection of an IPMN without malignancy is approximately 80%, 85% with malignancy but no lymph node spread and 0% with malignancy spreading to lymph nodes. Surgery can include the removal of the head of the pancreas (a pancreaticoduodenectomy), removal of the body and tail of the pancreas (a distal pancreatectomy), or rarely removal of the entire pancreas (a total pancreatectomy). In selected cases the surgery can be performed using minimally invasive techniques such as laparoscopy or robotic surgery. A study using Surveillance, Epidemiology, and End Result Registry (SEER) data suggested that increased lymph node counts harvested during the surgery were associated with better survival in invasive IPMN patients.

A pancreatic cyst is a fluid filled sac within the pancreas.

Causes range from benign to malignant. Pancreatic pseudocysts can occur in the setting of pancreatitis, though they are only reliably diagnosed 6 weeks after the episode of acute pancreatitis.

Benign tumors such as serous cystadenomas can occur. Main branch intraductal papillary mucinous neoplasms (IPMNs) are associated with dilatation of the main pancreatic duct, while side branch IPMNs are typically benign, and not associated with dilatation. MRCP can help distinguish the position of the cysts relative to the pancreatic duct, and direct appropriate treatment and follow-up. The most common malignancy that can present as a pancreatic cyst is a mucinous cystic neoplasm.

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.

Cysts from 1–5 mm on CT or ultrasound are typically too small to characterize and considered benign. No further imaging follow-up is recommended for these lesions. Cysts from 6–9 mm require a single follow-up in 2–3 years, preferably with MRCP to better evaluate the pancreatic duct. If stable at follow-up, no further imaging follow-up is recommended. For cysts from 1–1.9 cm follow-up is suggested with MRCP or multiphasic CT in 1–2 years. If stable at follow-up, the interval of imaging follow-up is increased to 2–3 years. Cysts from 2–2.9 cm have more malignant potential, and a baseline endoscopic ultrasound is suggested, followed by MRCP or multiphasic CT in 6–12 months. If patients are young, surgery may be considered to avoid the need for prolonged surveillance. If these cysts are stable at follow-up, interval imaging follow-up can be done in 1–2 years.

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.

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.

In 1982, IPMN was reported as a "mucin-producing tumor" by Kazuhiko Ohashi of the Japanese Foundation for Cancer Research.

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.

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

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.

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.

Pancreatic pseudocyst treatment should be aimed at avoiding any complication (1 in 10 cases become infected). They also tend to rupture, and have shown that larger cysts have a higher likelihood to become more symptomatic, even needing surgery. If no signs of infection are present, initial treatment can include conservative measures such as bowel rest (NPO), parenteral nutrition (TPN), and observation. Serum amylase levels can be trended. If symptoms do not improve by 6 weeks, surgical intervention may be appropriate.

In the event of surgery:

- Cystogastrostomy: In this surgical procedure a connection is created between the back wall of the stomach and the cyst such that the cyst drains into the stomach.

- Cystjejunostomy: In this procedure a connection is created between the cyst and the small intestine so that the cyst fluid directly into the small intestine.

- Cystduodenostomy: In this procedure a connection is created between the duodenum (the first part of the intestine) and the cyst to allow drainage of the cyst content into duodenum. The type of surgical procedure depends on the location of the cyst. For pseudocysts that occur in the head of the pancreas a cystduodenostomy is usually performed.

Pancreatic serous cystadenoma, also known as serous cystadenoma of the pancreas and serous microcystic adenoma, a benign tumour of pancreas. It is usually found in the head of the pancreas, and may be associated with von Hippel-Lindau syndrome.

In contrast to some of the other cyst-forming tumors of the pancreas (such as the intraductal papillary mucinous neoplasm and the mucinous cystic neoplasm), serous cystic neoplasms are almost always entirely benign. There are some exceptions; rare case reports have described isolated malignant serous cystadenocarcinomas. In addition, serous cystic neoplasms slowly grow, and if they grow large enough they can press on adjacent organs and cause symptoms.

Pancreas divisum in individuals with no symptoms does not require treatment. Treatment of those with symptoms varies and has not been well established. A surgeon may attempt a sphincterotomy by cutting the minor papilla to enlarge the opening and allow pancreatic enzymes to flow normally. During surgery, a stent may be inserted into the duct to ensure that the duct will not close causing a blockage. This surgery can cause pancreatitis in patients, or in rare cases, kidney failure and death.

An association with adenoma of the minor papilla has been reported.

The clinical management of a cyst of Montgomery depends upon the symptoms of the patient.

If there are no signs of infection, a cyst of Montgomery can be observed, because more than 80% resolve spontaneously, over only a few months. However, in some cases, spontaneous resolution may take up two years. In such cases, a repeat ultrasonography may become necessary. If, however, the patient has signs of an infection, for example reddening (erythema), warmth, pain and tenderness, a treatment for mastitis can be initiated, which may include antibiotics and non-steroidal anti-inflammatory drugs (NSAIDs). With treatment, inflammatory changes usually disappear quickly. In rare cases, drainage may become necessary. A surgical treatment of a cyst of Montgomery, i.e. a resection, may become necessary only if a cyst of Montgomery persists, or the diagnosis is questioned clinically.

The prognosis seems to be excellent. In one series, all adolescent patients with a cyst of Montgomery had a favourable outcome.

Although generally benign, the cyst must be removed if the patient exhibits difficulty in breathing or swallowing, or if the cyst is infected. Even if these symptoms are not present, the cyst may be removed to eliminate the chance of infection or development of a carcinoma, or for cosmetic reasons if there is unsightly protrusion from the neck.

Thyroid scans and thyroid function studies are ordered preoperatively; this is important to demonstrate that normally functioning thyroid tissue is in its usual area.

Surgical management options include the Sistrunk procedure, en bloc central neck dissection, suture-guided transhyoid pharyngotomy, and Koempel's supra-hyoid technique. Cystectomy is an inadequate approach.

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.

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.

A cyst is a closed sac, having a distinct membrane and division compared with the nearby tissue. Hence, it is a cluster of cells that has grouped together to form a sac (not unlike the manner in which water molecules group together, forming a bubble); however, the distinguishing aspect of a cyst is that the cells forming the "shell" of such a sac are distinctly abnormal (in both appearance and behaviour) when compared with all surrounding cells for that given location. It may contain air, fluids, or semi-solid material. A collection of pus is called an abscess, not a cyst. Once formed, sometimes a cyst may resolve on its own. When a cyst fails to resolve, it may need to be removed surgically, but that would depend upon its type and location.

Cancer-related cysts are formed as a defense mechanism for the body, following the development of mutations that lead to an uncontrolled cellular division. Once that mutation has occurred, the affected cells divide incessantly (and become known as cancerous), forming a tumour. The body encapsulates those cells to try to prevent them from continuing their division and to try to contain the tumour, which becomes known as a cyst. That said, the cancerous cells still may mutate further and gain the ability to form their own blood vessels, from which they received nourishment before being contained. Once that happens, the capsule becomes useless and the tumour may advance from benign to a cancer.

Some cysts are neoplastic and thus, are called cystic tumors; many types are not neoplastic. Some are dysplastic or metaplastic. Pseudocysts are similar to cysts (having a sac filled with fluid), but lack an epithelial lining.

The production of pancreatic enzymes is suppressed by restricting the patient's oral intake of food patient in conjunction with the use of long-acting somatostatin analogues. The patient's nutrition is maintained by total parenteral nutrition.

This treatment is continued for 2–3 weeks, and the patient is observed for improvement. If no improvement is seen, the patient may receive endoscopic or surgical treatment. If surgical treatment is followed, an ERCP is needed to identify the site of the leak.

Fistulectomy is done in which the involved part of the pancreas is also removed.

Treatment of accessory pancreas depends on the location and extent of the injured tissue. Surgery may be an option, or some physicians order prophylactic antibiotics.

The Sistrunk procedure is the surgical resection of the central portion of the hyoid bone along with a wide core of tissue from the midline area between the hyoid and foramen cecum. It involves excision not only of the cyst but also of the path's tract and branches, and removal of the central portion of the hyoid bone is indicated to ensure complete removal of the tract. The original Sistrunk papers (the "classic" procedure described in 1920, and the "modified" procedure described in 1928) are available on-line with a modern commentary.

In general, the procedure consists of three steps:

1. incision

2. resection of cyst and hyoid bone

3. drainage and closure

There are several versions of the Sistrunk procedure, including:

- "classic": excision of the center of the hyoid bone along with a thyroglossal duct cyst, removal of one-eighth inch diameter core of tongue muscle superior to the hyoid at a 45 degree angle up to the foramen cecum to include mucosa, removal of one-quarter inch of the center of the hyoid bone, closure of the cut ends of the hyoid bone, and placement of a drain.

- modified: dissection through the tongue base but not through the mucosa. The modified Sistrunk procedure is the procedure of choice in both primary and revision cases.

- hyoid cartilage division: In cases without mature ossification of the hyoid bone, the non-fused cartilage portion can be divided by monopolar Bovie electro-cauterization or scissors. There were no statistical differences between this modified Sistrunk and the conventional Sistrunk procedure.

The procedure is relatively safe. In a study of 35 pediatric patients, Maddalozzo et. al found no major complications, but did observe minor complications (6 patients presented with seroma and 4 patients with local wound infections). A more recent paper analyzed 24 research studies on different treatment complications of thyroglossal cyst, and reported a total minor complications rate of 6% for the Sistrunk operation (classical or modified) and simple cystectomy treatment modalities. The Sistrunk procedure also showed better outcomes concerning the rate of overall recurrence, i.e. has the lowest rate of recurrence.

Sistrunk procedure results in a 95% cure rate and 95–100% long-term survival.

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.

The cause of pancreatic pseudocyst can occur due to a variety of reasons, among them pancreatitis (chronic), pancreatic neoplasm and/or pancreatic trauma.