Cysts are closed capsules or sac-like structures, usually filled with liquid, semi-solid, or gaseous material, much like a blister. We’re going to define the different types in this post.
Cysts are located within the tissue and can affect any part of the body. They vary in size, ranging from microscopic to some team-sport balls. Inner organs may be replaced by very large cysts.
In anatomy, any common bag or sac in the body such as the bladder may also be referred to by a cyst. Throughout this article, cyst refers to an irregular bag or pocket containing liquid, gaseous, or semisolid substances in the body.
A cyst is not a natural part of the tissue in which it is located. It has a distinct membrane and is isolated from surrounding tissue — the cyst wall is considered the outer (capsular) part of a cyst. When pus fills the sac it is not a cyst; it is an abscess.
Important facts about cysts
Here are a few key points about cysts. The main article includes more descriptions and supporting information.
- Cysts are usually noncancerous and have a sac-like structure that can contain fluid, pus, or gas.
- Cysts are common and can occur anywhere on the body.
- Cysts are often caused by infection, clogging of sebaceous glands, or around earrings.
- It is unusual for cysts to cause pain unless they rupture, become infected, or inflamed.
- Breast cysts are often painful and may be noticeable during a breast examination.
What causes cysts?
Common causes of cysts include:
- tumors
- genetic conditions
- infections
- a fault in an organ of a developing embryo
- a defect in the cells
- chronic inflammatory conditions
- blockages of ducts in the body that cause fluids to build up
- a parasite
- an injury that breaks a vessel
Benign and malignant cysts
Most cysts are benign and are caused by normal drainage system blockages in the body. Some cysts, however, may be tumors developing within tumors — these may potentially be malignant. Examples contain keratocysts and dermoids cysts.
Symptoms of cysts
Signs and symptoms differ significantly due to what sort of cyst it is. In several cases, a person becomes aware of an irregular lump, particularly in cases with skin cysts or when a cyst is just below the skin. A individual can feel a cyst in their breasts by touching them, when they examine them. Breast cysts are sometimes painful.
Some brain cysts may cause headache, as may other symptoms.
Many inner cysts, such as those in the kidneys or in the liver, can have no signs and go unnoticed until they are detected by an imaging scan (MRI scan, CAT scan, or ultrasound).
Types of cysts
Some of the most common types of cysts are listed below:
Acne cysts
Cystic, or nodulocystic, acne is a severe form of acne which blocks the pores in the skin, causing infection and inflammation.
Arachnoid cysts
The arachnoid membrane protects the spine. During fetal development the arachnoid membrane doubles up or divides to create an irregular pocket of cerebrospinal fluid. In certain cases, the cyst must be removed by surgeons. Arachnoid cysts may have an effect on newborns.
Baker’s cysts
Baker’s cysts are also called popliteal cysts. A person with the cyst of a Baker sometimes feels a bulge behind the knee, and a sensation of tightness. Pain gets worse during knee prolongation or during physical exercise. Baker’s cysts are usually caused by a knee joint problem, including arthritis or a tear of cartilage.
Bartholin’s cysts
This may occur when the Bartholin glands ducts (located inside the vagina) are blocked. Women may undergo surgery, and/or have antibiotics prescribed.
Breast cysts
Breast cysts are often uncomfortable and should usually be drained. Some studies have shown that the breast cysts can suggest an increased risk of breast cancer.
Chalazion cysts
Quite small eyelid glands (meibomic glands) create a lubricant that emanates from tiny openings in the eyelid edges. Where the ducts are blocked, cysts can form.
Colloid cysts
There are cysts containing gelatinous content within the brain. In most cases, surgical removal of the cyst is recommended as the treatment.
Dentigerous cysts
These are cysts surrounding the crown of an unerupted tooth.
Dermoid cysts
Dermoid cysts are a form of cyst that includes mature skin, hair follicles, sweat glands, long hair clumps, and also fat, bone, cartilage, and thyroid tissue.
Epididymal cysts
There are cysts formed in the vessels attached to the samples (spermatocele). It is estimated that this form of cyst affects 20-40 percent of American males and does not usually impair fertility or require care. If this causes pain a doctor might recommend a surgery.
Ganglion cysts
You can read more about these in our dedicated article: What is a ganglion cyst?
Hydatid cysts
A relatively tiny tapeworm develops lung or liver cysts. Treatment involves the medicine and surgery.
Ovarian cysts
The majority of ovarian cysts are benign. Some can become so large that the woman looks pregnant. Ovarian cysts 5 centimeters (cm) long or less are common during a woman’s reproductive years. Up to 18 percent of females will be diagnosed with an ovarian cyst or tumor at some time in their life, and a small percentage of them will be diagnosed with ovarian cancer.
Pancreatic cysts
Most pancreatic cysts aren’t considered real cysts. They are called pseudocysts, because they do not include the cell type contained in true cysts. They can contain cells usually found in other organs, such as the intestines or the stomach.
Periapical cysts
Such, too, are called radicular cysts. They are the most common odontogenic cyst (related to teeth formation and development), and are typically caused by pulp inflammation, pulp death, or dental caries.
Pilar cysts
These are also known as trichilemmal cysts. They are fluid-filled cysts that form from a hair follicle and are most commonly found in the scalp.
Pilonidal cysts
Such cysts develop near the tailbone (bottom back) in the skin, and can often contain ingrown hair. This type of cyst can develop in clusters, forming a hole or cavity in the skin at times.
Renal cysts (kidneys)
In the kidneys several types of cysts can develop. Solitary cysts contain fluids, which can include blood at times. Many are present at birth; others can be caused by blockages in tubules. People with kidney vascular disease may have kysts that are formed by blood vessel dilation.
Pineal gland cysts
These are benign cysts that form in the pineal gland in the brain. According to autopsy records, pineal gland cysts are fairly common.
Sebaceous cysts
People also use the term sebaceous cyst to describe a form of cyst on face, back, scalp, or scrotum skin. Cysts that occur in such areas may be epidermoid or pilar cysts, but after extracting and examining the cyst, doctors can only say the difference.
Tarlov cysts
Which are also known as perineural / perineurial cysts, as well as root cysts of sacral nerves. The cysts occur at the base of the spine and are full of cerebrospinal fluid.
Vocal fold cysts
There are two types of vocal fold cysts – mucus retention cysts and epidermoid cysts. Vocal folding cysts can interfere with the quality of the speech of the individual, often causing vocal cords to produce multiple tones at the same time (diplophonia), or heaviness and breathable speech (dysphonia).
Treatments for cysts
Treatment for a cyst may rely on multiple factors including the type of cyst where it is, the size of the cyst, and the degree of pain caused.
A very large cyst which causes symptoms can be surgically removed. Occasionally, doctors may attempt to drain or aspire the cyst by inserting a needle or a catheter into the cavity. If the cyst is not readily available, drainage or aspiration is often done with the assistance of radiological imaging so that the doctor can precisely guide the needle / catheter into the target region.
Often under a microscope, doctors analyze the aspired substance to assess if there are cancerous cells.
If physicians believe the cyst may be cancerous, it may be surgically removed, or they may order a capsule biopsy (cyst wall).
As with fibrocystic breast disease or polycystic ovary syndrome, often cysts occur as a result of a chronic or underlying medical condition – in these cases, the focus of care is on the medical condition.
