Cyst is a balloon-shaped mass filled with fluid. Cysts are separated from the adjacent organs by a thin layer called "cyst wall". Practically, cyst may occur in each organ. However, they are most frequently seen in the liver, kidney, ovary and breast.

Some of the cysts may be congenital. Or they may develop due to some hereditary diseases (such as polycystic kidney disease, Von Hippel Lindau disease). Some may develop due to previous operations or infection (such as lymphocel, hydatid cyst). However, in most patients, cysts occur independent from a specific cause and grow with age. Some of the cysts may not give any symptoms. In some cases, problems such as pain, bloating, nausea and increased blood pressure may occur due to compression of the surrounding tissue.

Because of the widespread use of imaging methods such as ultrasound, CT and MRI, cysts are more commonly detected than in the past. Small cysts that do not cause any complaints need not be treated, follow-up is sufficient. However, if the cysts are large, show rapid growth or cause complaints, treatment is usually necessary. Surgery, which was once the only treatment for cysts, is rarely practiced today. The standard treatment for cysts is image-guided sclerotherapy.

Can the cyst be cancerous?

Cysts are divided into ”simple cysts and complicated cysts based on the imaging findings. The simple cyst has a thin, smooth wall and only liquid is present. In the complicated cyst, the wall may be thick and irregular and there are solid portions in the cyst besides the fluid. It is assumed that simple cysts are not related to cancer; such cysts are not biopsied. They are either followed up, or treated with sclerotherapy. Complicated cysts are usually due to events such as abscesse, hemorrhage and infection, but a small proportion may also be found to be cancer. In such cysts, the fluid content should be taken out with a needle. In some cases, a needle biopsy should be taken from the solid part of the cyst and pathology examination may be necessary. According to the results of these examinations, the patient can only be followed up or treated with surgery.

Liver cysts:

The most common cysts in the liver are simple cysts and hydatid cysts. Simple cysts, like other organs, have a thin and smooth wall and nothing more than liquid. Hydatid cysts are also known as "dog cysts". They are more likely to spread to people by eating vegetables and fruits that have come into contact with dog feces. In the hydatid cysts, ultrasound, CT and MRI usually show single cysts with thin membranes or numerous grape-like small cysts. In thise cases, distinction from simple cysts is easy. Sometimes, however, hydatid cysts may resemble simple cysts. In this case, these two conditions can be distinguished by special blood tests.

Sclerotherapy is the most common treatment modality in simple cysts in liver. For this purpose, a thin needle is inserted into the cyst under ultrasound guidance and by injecting contrast media any connection of the cyst with the bile ducts is investigated. If there is no connection, cyst fluid is removed and an appropriate amount of alcohol is injected. Most simple cysts become significantly smaller or disappear after this single-session treatment. However, in some cases, treatment with a second session or catheter may be required.

In the hydatid cyst, the treatment is done also with the needle, but it is slightly different from the simple cyst treatment. The details of this subject are given under the heading "Hydatid Cyst".

Renal cysts:

Simple cysts in the kidney are very common. In one study, simple cysts in the kidney were detected in half of the individuals over 50 years of age. Most of these cysts are small, have no symptoms and do not require treatment. However, if the cysts are above 5 cm, they grow or cause problems such as pain, bleeding in the urine, infection, and hypertension, they should be treated. The most commonly used treatment for renal cysts is alcohol sclerotherapy. Studies have shown that more than 90% of cysts either shrink or disappear with single-session sclerotherapy.

Simple cysts in the kidney can sometimes develop due to a hereditary disease called "polycystic kidney disease". In this disease, there are numerous simple cysts within the kidney and patients develop renal failure in advanced ages. In such patients, cysts can be treated by sclerotherapy if cysts cause pain.

Although it is rarely seen in the kidney, hydatid cyst may be seen and treated with sclerotherapy. Very rarely kidney cancer can be seen as a cyst on CT or MRI. In this case, diagnosis should be made by needle biopsy.

Ovarian (ovarian) cysts:

Ovarian (ovarian) cysts are quite common. Most of these cysts are simple cysts, and the second most common are cysts of endometriosis (chocolate cyst). Most simple cysts do not require treatment. Many of these cysts may spontaneously regress, and some may be smaller with oral medications. But a small part of simple ovarian cysts can may grow. Chocolate cysts are cysts filled with blood. These cysts occur due to endometriosis and can cause severe pain during menstruation.

Surgical operation is recommended in most of the growing cysts and painful chocolate cysts. However, because the surgical operation requires general anesthesia and incision and there are risks such as infection and adhesion surgery is not preferred by most patients. Therefore, different non-surgical treatment methods have been applied all over the world. Of these, ultrasound guided sclerotherapy is the most preferred. In this procedure, a thin needle is introducedinto the cyst from the skin under local anesthesia. After the cyst fluid is removed, some medications that destroy the inner layer of the cyst are given and the needle is then taken out. The cyst fluid is also examined in the pathology. The most commonly used substance for sclerotherapy is alcohol. The cyst, whose inner wall is destroyed, becomes smaller and may sometimes disappear.

Ultrasound-guided sclerotherapy has been successfully used in both cysts and chocolate cysts (endometriosis) in the ovaries. In various studies conducted in the literature, after ultrasound guided sclerotherapy, 82-85% of ovarian cysts were found to be permanently shrunk or disappeared. In patients with endometriosis, addition, besides the shrinkage of cysts, the pain either diminished or disappeared in most patients.

In ovarian cysts, sclerotherapy should be performed only in patients with "benign" characteristics and with normal CA-125 levels. Several studies have shown that the likelihood of ovarian cancer is close to zero in such patients. For example, in a study published in 2003, 2763 patients over 50 years of age with ovarian cysts smaller than 10 cm were followed up and no cancer was observed in any of the patients who retained simple cyst characteristics on ultrasound. Considering that the risk of ovarian cancer is even lower before 50 years of age, it is obvious that the risk of cancer is very low in such patients and that ultrasound is a valuable method in the differentiation of simple cyst and suspected cancer. In conclusion, ultrasound-guided sclerotherapy should be performed after a good evaluation of ultrasound and CA-125 values in the blood and surgery should be preferred in patients with suspected cancer.

Breast cysts:

Breast cysts are very common in the community. Most of these cysts are simple cysts and cysts due to other causes are rare. The majority of breast cysts are small and do not cause any complaints. However, sometimes cysts can grow, protrude from the skin and cause pain. In this case, treatment is usually performed. Nowadays, surgery for breast cysts has been largely abandoned. Instead, most surgeons try to put a needle into the cyst by examining the cyst by hand without using ultrasound, and take the liquid inside. However, this approach is inconvenient for 2 reasons. First, in some patients, the hand mass may not be the cyst itself, and the needle inserted in this way without seeing with ultrasound can go to the wrong places. Secondly, it is often unhelpful to only drain the liquid of the cyst. In such patients, most cysts come back to their original size, so the treatment is not successful. For these reasons, if the breast cysts are to be treated, the cystshould be punctured by ultrasound imaging under local anesthesia, the cyst content should be taken out and then the inner wall of the cyst should be destroyed by giving alcohol under ultrasound guidance. In the literature, it has been reported that over 95% of the breast cysts disappear completely after 6 months of this treatment. However, this treatment should be performed with ultrasound guidance and by experienced physicians. Because, if the alcohol is mistakenly given out of the cyst, serious problems may develop in normal breast tissue.