A pilonidal cyst can resemble a dermoid cyst, a kind of teratoma (germ cell tumor). In particular, a pilonidal cyst in the gluteal cleft can resemble a sacrococcygeal teratoma. Correct diagnosis is important because all teratomas require complete surgical excision, if possible without any spillage, and consultation with an oncologist.

The cystic nature of a breast lump can be confirmed by ultrasound examination, aspiration (removal of contents with needle), or mammogram. Ultrasound can also show if the cyst contains solid nodules, a sign that the lesion may be pre-cancerous or cancerous. Examination by a cytopathologist of the fluid aspirated from the cyst may also help with this diagnosis. In particular, it should be sent to a laboratory for testing if it is blood-stained.

Commonly, cysts are detected with the help of mammograms. However, the medical history and physical examination also play an important role in establishing an accurate diagnosis. During these tests, the doctor will try to find out as much information as possible regarding the symptoms the patient has experienced, their intensity and duration and the physical examination is performed regularly to check for other abnormalities that may exist within the breast.

As mentioned above, cysts are often undetectable at touch. Therefore, a mammogram can provide valuable and clear images of the breast tissue. Generally, if there is any abnormality within the breast tissue, it will be shown on the mammogram. There are two types of mammograms available. One of them is primarily used in screening, and are ordered for patients who do not show any symptoms and these are called screening mammograms. Diagnostic mammograms are used on patients who developed certain symptoms of a breast condition or in patients whose screening mammograms showed abnormalities.

Patients suspected of breast cysts will normally be given a diagnosing mammogram, although they are not suspected of cancer. This type of mammogram provides the doctor with the possibility of performing a breast ultrasound at the same time and this is the reason why they are often preferred over the screening mammograms. Breast ultrasound is considered the best option when diagnosing breast cysts because it is 95 to 100% accurate, it provides a clear image on the cyst's appearance (simple or complex) and it may also distinguish between solid lumps and fluid-filled cysts, which a mammogram cannot do. Breast ultrasounds are performed with the help of a handheld medical instrument which is placed on the skin, after a special type of fluid has been applied on it. The instruments picks up the echo resulted from the sound waves it sends to the breast. These echoes are transmitted to a computer which translates it into a picture.

Breast cysts may remain stable for many years or may resolve spontaneously. Most simple cysts are benign and do not require any treatment or further diagnostic workup. Some complex cysts may require further diagnostic measures such as fine needle aspiration or biopsy to exclude breast cancer however the overwhelming majority is of benign nature. Aspiration both diagnoses and removes cysts at the same time. That is, cysts will usually resolve on their own after the fluid is drained. Otherwise, if the lump is not a cyst, the fluid aspirated may contain blood or there may not be fluid at all. Whereas in the first case, the fluid is sent to the laboratory for further examination, the latter circumstance is a sign that the breast lump is solid. This type of tumor needs to be biopsied in order to determine whether it is malignant or benign.

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.

While Bartholin cysts can be quite painful, they are not life-threatening. New cysts cannot absolutely be prevented from forming, but surgical or laser removal of a cyst makes it less likely that a new one will form at the same site. Those with a cyst are more likely than those without a cyst to get one in the future. They can recur every few years or more frequently. Many women who have marsupialization done find that the recurrences may slow, but do not actually stop.

A cyst of Montgomery may be asymptomatic. Yet, a cyst of Montgomery usually is diagnosed when a female patient, 10–20 years of age, complains to a healthcare professional of breast pain (mastalgia), inflammation or a palpable nodule in the breast. The diagnosis is made clinically, when a palpable nodule is felt in the retroareolar area.

The diagnosis can be confirmed with ultrasonography, frequently showing a simple cyst in the retroareolar area. In some patients, multiple cysts or bilateral cysts may exist. Cysts of Montgomery may have liquid content with an echogenic or calcific sediment.

The diagnostic process typically begins with a medical history workup followed by a medical examination by a physician. Imaging tests, such as CT scans and MRIs, help provide a clearer picture. The physician typically looks for fluid (or other bodily substance) filled sacs to appear in the scans, as is shown in the CT scan of a colloid cyst. A primary health care provider will refer an individual to a neurologist or neurosurgeon for further examination. Other diagnostic methods include radiological examinations and macroscopic examinations. After a diagnosis has been made, immunohistochemistry may be used to differentiate between epithelial cysts and arachnoid cysts. These examinations are useful to get a general idea of possible treatment options, but can be unsatisfactory to diagnose CNS cysts. Professionals still do not fully understand how cysts form; however, analyzing the walls of different cyst types, using electron microscopes and light microscopes, has proven to be the best diagnostic tool. This has led to more accurate cyst classification and correct course of action for treatments that are cyst specific. In the past, before imaging scans or tests were available, medical professionals could only diagnose cysts via exploratory surgery.

Other conditions that may present similarly include hidradenoma papilliferum, lipomas, epidermoid cysts and Skene's duct cysts among others. In those who are more than 40 years of age a biopsy may be recommended to ensure cancer is not present.

Ultrasound is the often chosen to examine the duct and determine the presence and size of any cysts or abnormalities. Fine-needle aspiration cytology can also be used to confirm the diagnosis.

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.

Epidermoid cysts are usually diagnosed when a person notices a bump on their skin and seeks medical attention. The definitive diagnosis is made after excision by a pathologist based on microscopic appearance of a cystic lesion lined by cornified epithelium containing lamellated keratin without calcifications. They can also be seen as isointense lesions on MRI or hyperintensities on FLAIR.

Lymphatic malformations may be detected in the human fetus by ultrasound if they are of sufficient size. Detection of a cystic malformation may prompt further investigation, such as amniocentesis, in order to evaluate for genetic abnormalities in the fetus. Lymphatic malformations may be discovered postnatally or in older children/adults, and most commonly present as a mass or as an incidental finding during medical imaging.

Verification of the diagnosis may require more testing, as there are multiple cystic masses that arise in children. Imaging, such as ultrasound or MRI, may provide more information as to the size and extent of the lesion.

Ganglion cysts are diagnosed easily, as they are visible and pliable to touch.

Radiographs in AP and lateral views should be obtained to exclude any more serious underlying pathology. Ultrasonography (US) may be used to increase diagnostic confidence in clinically suspected lesions or to depict cysts, because intratendinous ganglia are readily distinguished from extratendinous ganglia during dynamic ultrasonography, as microscopically, ganglionic cysts are thin-walled cysts containing clear, mucinous fluid.

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."

Clinical features can be found in the subhyoid portion of the tract and 75% present as midline swellings. The remainder can be found as far lateral as the lateral tip of the hyoid bone.

Typically, the cyst will move upwards on protrusion of the tongue, given its attachment to the embryonic duct, as well as on swallowing, due to attachment of the tract to the foramen caecum.

Some mucoceles spontaneously resolve on their own after a short time. Others are chronic and require surgical removal. Recurrence may occur, and thus the adjacent salivary gland is excised as a preventive measure.

Several types of procedures are available for the surgical removal of mucoceles. These include laser and minimally-invasive techniques which means recovery times are reduced drastically.

Micro-marsupialization is an alternative procedure to surgical removal. Micro-marsupialization uses silk sutures in the dome of a cyst to allow new epithelialized drainage pathways. It is simpler, less traumatic, and well-tolerated by patients, especially children.

A non-surgical option that may be effective for a small or newly identified mucocele is to rinse the mouth thoroughly with salt water (one tablespoon of salt per cup) four to six times a day for a few days. This may draw out the fluid trapped underneath the skin without further damaging the surrounding tissue. If the mucocele persists, individuals should see a doctor to discuss further treatment.

Smaller cysts may be removed by laser treatment, larger cysts will have to be removed surgically in an operating room.

Colloid cysts can be diagnosed by symptoms presented. Additional testing will be required and the colloid cyst symptoms can resemble those of other diseases. MRI and CT scans are often used to confirm diagnosis.

Diagnosis of a thyroglossal duct cyst requires a medical professional, and is usually done by a physical examination. It is important to identify whether or not the thyroglossal cyst contains any thyroid tissue, as it can define the degree of cyst that is being dealt with.

Diagnostic procedures for a thyroglossal cyst include:

Diagnosis is principally by MRI. Frequently, arachnoid cysts are incidental findings on MRI scans performed for other clinical reasons. In practice, diagnosis of symptomatic arachnoid cysts requires symptoms to be present, and many with the disorder never develop symptoms.

Additional clinical assessment tools that can be useful in evaluating a patient with arachnoid cysts include the mini-mental state examination (MMSE), a brief questionnaire-based test used to assess cognition.

The development of breast cysts may be prevented to some degree, according to the majority of the specialists. The recommended measures one is able to take in order to avoid the formation of the cysts include practicing good health and avoiding certain medications, eating a balanced diet, taking necessary vitamins and supplements, getting exercise, and avoiding stress.

Although caffeine consumption does not have a scientifically proved connection with the process of cyst development, many women claim that their symptoms are relieved if avoiding it. Some doctors recommend reducing the amount of caffeine in one's diet in terms of both beverages and foods (such as chocolate). Also reducing salt intake may help in alleviating the symptoms of breast cysts, although, again, there is no scientific linkage between these two. Excessive sugar consumption as well as undetected food allergies, such as to gluten or lactose, may also contribute to cyst development.

A neurosurgeon performs a craniotomy as a means of entry to access the cyst. The cyst is then opened to release its contents, which are reabsorbed by the brain. This is commonly used with inflammatory cysts located in the ventricles, and can result in increased ventricular fluid flow within the brain.

a nuclear imaging method to evaluate any degenerative and/or arthritic changes in the joints; to detect bone diseases and tumors; to determine the cause of bone pain or inflammation. This test is to rule out other cysts (which are quite unusual)

CT scans use x-rays and computer technology to produce accurate axial, coronal, and sagittal images. CT scans are more detailed than x-rays because they can create images that show fat, muscles, organs, and bones.

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.

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.

Most cysts are discovered as a chance finding on routine dental radiography. On an x-ray, cysts appear as radiolucent (dark) areas with radiopaque (white) borders. Cysts are usually unilocular, but may also be multilocular. Sometimes aspiration is used to aid diagnosis of a cystic lesion, e.g. fluid aspirate from a radicular cyst may appear straw colored and display shimmering due to cholesterol content. Almost always, the cyst lining is sent to a pathologist for histopathologic examination after it has been surgically removed. This means that the exact diagnosis of the type of cyst is often made in retrospect.