What is a Cyst?
A cyst is a fluid-filled cavity in the tissue which is closed by a capsule. Cysts can consist of one or more chambers and are found in various tissues or organs. The term cyst comes from the Greek word “kystis” which translates to bladder or urinary bladder.
Medics distinguish real cysts and pseudocysts. Genuine cysts are lined with a layer of cells, while pseudocysts are only surrounded by connective tissue. Cysts can occur in any part of the body and at any age. They can be tiny and only recognizable with the microscope or become so large that they displace other organs or tissues.
What Are The Causes of Cysts?
There are many different causes of cysts. Some are formed because a fluid can not run unimpeded (eg sebaceous glands of the skin, a kind of blackheads), others in chronic diseases (cystic fibrosis in mucoviscidosis), hereditary diseases (such as cystennias or cystles), tumors or developmental disorders in the embryo, Parasites (such as dog or foxes, echinococcosis) can also cause these.
In addition, cysts can form under the influence of hormones, such as the female breast, the ovaries, or testes.
Complaints and Diagnosis
Which symptoms cause cysts and how to diagnose cavities depends on the nature of the cyst and the place of origin. Some cysts manifest themselves through a visible or palpable swelling, for example, a cyst in the breast.
Other cysts do not occur for a long time because they are located on internal organs (for example the kidney or liver) and are usually only discovered during a routine ultrasound examination.
Other imaging techniques such as computed tomography (CT), MRI (magnetic resonance imaging), radiographs, and blood tests are sometimes necessary to determine the size and cause of the cyst.
In some cysts, the physician touches the cavity with a fine needle, removes a sample of the liquid contents, and examines them under a microscope (cyst puncture).
Most cysts are benign. But also harmless cysts can cause discomfort, for example when they become very large and displace other organs or tissues.
Some cysts are caused by malignant tumors or behave aggressively, for example, in case of an infection with the foxes (echinococcosis). The therapy depends on the type and location of the cyst.
Frequently occurring cysts are:
- Renal cysts
- Liver cysts
- Ovarian cysts (ovarian cysts)
- Fracture of the testis (hydrocele)
- Cysts in the knee (Baker’s cyst)
- thyroid cysts
- Cysts in the glands on the eyelid
- Sebaceous glands of the skin
- Cysts in the chest
- Bone cysts
- Root cysts
Renal cysts may occur singly or in more than one of the two kidneys. They usually do not cause any discomfort and are usually discovered by chance. Large cysts sometimes manifest themselves through pain in back or belly.
Cysts in the kidney can sometimes ignite or burst, or it can bleed into the cyst. Rare cysts are malignant. They are isolated in combination with a tumor of the blood vessels (hemangioblastoma) of the cerebellum or the retina.
Renal cysts are rare in people under 30 years of age. As they grow older, they occur more frequently. More than 20 percent of over 60s have one or more cysts on the kidneys.
A cyst on the kidney which causes no problems do not need to be treated. Large cysts that are associated with pain or complications can be punctured with a needle to aspirate the fluid contained (puncture). The fluid of the cyst can be examined under the microscope. Under certain circumstances, the cyst can become deserted or removed in an operation.
Polycystic Kidney Disease
Simple renal cysts must not be confused with cystic kidneys. Polycystic kidney disease (Autosomal Polycystic Kidney Disease, ADPKD) is one of the most common hereditary diseases. It occurs in about one thousand people.
Because of changes in the genome (PKD1 or PKD2 gene), the affected individuals develop more and more cysts in the kidneys as long as the organs are no longer functioning. After about 50 years, most patients suffer from renal failure (renal insufficiency).
The disease affects not only the kidneys. Cysts can also form in other organs (for example the pancreas, liver, lungs, spleen, the ovaries, the uterus, the testes or the thyroid gland).
The polycystic kidney disease can lead to various complications and is not yet curable. Treatment is only necessary if symptoms such as urinary retention or urinary tract infections occur.
Currently, there is no drug with which cystic kidneys can be treated. The therapy aims to relieve the symptoms.
About three to five percent of people over the age of 50 have single, occasionally several cysts in the liver. The cysts usually do not cause any discomfort.
In most cases, they are accidentally discovered during an ultrasound examination. Large cysts over ten centimeters in diameter can cause a feeling of pressure in the upper abdomen, nausea, or a lump.
As a rule, cysts do not have to be treated. If the patient is prepared to complain, the physician can infect the cyst through the skin with a fine needle, suck off its contents, and inject an alcohol solution which will degrade the cyst. Rarely the cyst must be removed in one operation (cyst resection).
Not all liver cysts are harmless. Also an infection with the dog or foxes can cause cysts in the liver. Echinococcosis is a serious disease that is fatal without treatment.
Polycystic Liver Disease
The cyst is a hereditary disease. About 0.6 percent of the population suffers from Adult Polycystic Liver Disease (APLD). Approximately half of those affected also had cysts in the kidneys (polycystic kidney disease, APKD). An APLD is produced by changes to the genome (mutations). This concerns the genes PKD-1 and PKD-2.
The cysts cause a feeling of pressure and pain in the abdomen, depending on the size. If the cysts become larger and larger, they can press on the stomach and intestines. The patients have no appetite and show a weight loss.
The function of the liver remains however for a long time preserved. The cysts can be recognized by ultrasound. The symptoms can be alleviated in the short term if the doctor punctures the cysts and sucks the liquid.
After a while, fluid usually drains and the cysts fill again. If the cysts cause problems, the surgeon can remove a portion of the liver (liver partial resection). In some cases, only a liver transplant can help.
Ovarian cysts are usually caused by normal hormonal fluctuations during the female cycle. They can also occur when a woman takes hormones.
Ovarian cysts often cause no discomfort. Sometimes acute abdominal pain occurs, for example when a cyst bursts. If a pedunculated cyst rotates around its own axis, acute, severe abdominal pain can occur.
The treatment depends on the symptoms and the size of the cyst. In many cases, you can wait and see. Some women help to suppress ovulation (for example the pill). If these do not improve, the cysts can be surgically removed during laparoscopic cyst exstirpation.
Eight and more cysts in an ovary can be an indication of the syndrome of polycystic ovaries (PCO syndrome). In this disease, the ovaries increasingly form male sex hormones. Even in endometriosis, a disease in the uterine lining grows outside the uterus, ovarian cysts can occur.
Endometriosis cysts are typically filled with degradation products of the blood. Because of their brown color, they are called chocolate cysts.
Cysts on the ovary can also occur due to a defective development during the embryonic period. These include the dermoid cysts. There may be other types of tissue, such as hair or teeth.
A hydrocele describes a buildup of fluid in the scrotum. It can be congenital or acquired in the course of life. With the ultrasound, the physician can clearly recognize the hydrocele and delineate it against other changes in the testicle (for example, a tumor).
In a congenital hydrocele, the boy’s first year of life can be waited if he has no complaints. Sometimes the hydrocele forms spontaneously at this time. Older children with a congenital hydrocele are operated on, because they can later get a hernia (groin hernia).
Cyst in the Knee
A Baker cyst is a cyst that emanates from the posterior joint capsule in the knee joint. The cyst arises in diseases affecting the knee, in which a chronic joint effusion occurs, for example in rheumatic diseases. The posterior joint capsule protrudes and the cyst forms.
Many sufferers have pain when bending the knee. In rheumatic diseases the cyst can become so large that it continues into the lower extremities. Large cysts can squeeze blood vessels.
Small cysts cause little discomfort and do not have to be treated. Often the Baker’s cyst forms spontaneously when the basic disease is successfully treated. Large cysts that cause discomfort may be surgically removed.