Unicameral Bone Cysts


A unicameral Bone Cysts or a simple bone cyst is a type of noncancerous (benign) bone tumor. It mainly occurs in adolescents and children.


Within a bone, unicameral bone cysts (UBC) are cavities that contain fluid in them. Moreover, they mostly develop in long bones of the body such as the thighbone (femur) and upper arm bone (humerus). However, they can affect any bone in the body.


In many cases, unicameral bone cysts do not develop any pain. Moreover, you may discover them accidentally when you perform an X-ray for some other reason.


Furthermore, fractures may result through UBCs as these cysts make the surrounding bones weaker. Treatment varies with several factors like risk for fracture, size, and location of the cyst. Furthermore, in certain cases, surgery is more beneficial than other forms of treatment.



It is not clear what leads to unicameral bone cysts. However, some researchers believe that one develops these Cysts because of two reasons. One is the development of an outgrowth from the growth plate. Another one is the development of abnormal pockets of tissue surrounding the joints.



It is necessary to mention that most of the unicameral bone cysts do not cause any symptoms. Thus, you may discover them accidentally. The discovery of the cyst occurs when you perform a test, unrelated to the problem.


Furthermore, some patients may discover cysts when bone breaks. The cyst causes no symptoms. Thus, it can expand and make the bones weaker. This leads to a fracture in the bones.


Therefore, with just a minor injury, your bone may break. “Pathologic fracture” is the term for such fractures. Less commonly, if a cyst leads to enlargement in a local area, then you may notice a painless bump.


Doctor examination.

Your doctor will ask for various imaging tests to confirm a unicameral bone cyst. Most importantly, he/she may use X-rays.


X-rays. These tests show a UBC clearly. They provide clear details of dense structures such as bones. Mostly, to diagnose a unicameral bone cyst, the only imaging test that your doctor may require is a plain X-ray.



Differential Diagnosis. Sometimes, to distinguish a unicameral bone cyst from other noncancerous bone cysts, your doctor may use additional imaging tests. Other similar bone cysts may include an aneurysmal bone cyst.

In an X-ray, an aneurysmal bone cyst resembles a UBC. However, a group of blood-filled cysts results in the formation of an aneurysmal bone cyst.


Occasionally, this type of cysts can lead to serious deformity to the bone. This occurs because the tumor grows very large. Moreover, unicameral and Aneurysmal bone cysts need different methods of treatment.


In certain cases, to get more details about the cyst, your doctor may order other tests. These tests may include a computerized tomography (CT) scan or an MRI scan.


There will be multiple cavities present in an MRI scan of an aneurysmal bone cyst. The fluid is present in these cavities. While a single cavity is present in the case of a UBC which differentiates the two.


After that, a biopsy may become necessary if these tests do not reveal the results. In a biopsy, your doctor will take a sample of tissue from your body. Then he/she will look for changes in them if any. This test gives you accurate results.



An appropriate treatment will depend upon a range of factors. For instance, our treatment depends upon the strength of the bone, size of the cyst, the activity level of your child. Further, it also depends upon the symptoms that your child may be facing.


If the cyst is minute and does not cause any symptoms, then your doctor will simply observe it. However, if the cysts are large enough, then your doctor will recommend surgery.


It is because it may cause a breakage of bones, even with a mild force. In such cases, to reduce the risk of fracture, surgery becomes necessary.


Moreover, if cysts have already broken the bone, then surgery may not be necessary. This is because the bone heals naturally. 25 percent of the cysts heal completely, along with a fracture.


However, your doctor may recommend surgery again if the cyst is still present. This helps prevent another fracture.


Nonsurgical Treatment

Observation. In certain cases, carefully observing the tumor is the main form of treatment. To keep the track of any probable changes in the cyst, your doctor may order your X-rays regularly.


Activity Modification. The chances of a fracture are very less if your child is not active in certain high-risk activities and sports. Your doctor may order you for a minimal amount of activity along with regular observation. You may have to do this until your child grows fully and the cyst resolves.


Surgical Treatment. In some cases, your doctor may recommend surgery. For instance, if the cyst is growing larger, or is painful, or present in a location that can cause a fracture. Various operations show efficient results in different patients.


Aspiration and injection. In this method, your doctor drains fluid from your cysts by inserting needles. It is named as aspiration.


To decrease the chance of cancer coming back, your doctor will then inject the cysts with some substances. Sometimes, your doctor may give you a series of injections over a few months.


Curettage and bone graft. In this method, your doctor aspirates the cysts and then scraps them out of the bone. Then your surgeon will fill the hole with a graft.


The graft could be from another bone in your body (autograft) or a donor (allograft). To fill the hole, your doctor will then use a bone cement mixture.


Before surgery, your child will be put to sleep by giving general anesthesia. After the surgery, your child will be able to go home soon. He/she may carry their daily activities accordingly.


Coping and support 


When you get diagnosed with unicameral bone cysts, it could be frightening for you. The condition will be no different for your family.


However, you may learn to cope with the uncertainty and distress related to cancer with time.  Thus, you need to follow these instructions until then;


Call on for medical support:


Various things are going to help you. For instance, the knowledge and understanding of a medical social worker, or any other mental health professional is necessary. They will help you in understanding your cancer.


Furthermore, if your child or other family member suffers from cancer, you need to ask health care professionals for advice. They will provide you with options for medical health support. This will also provide you with emotional and social support.


In addition to this, you can check various online services that will provide you support to combat cancer.


  • Gain more knowledge about unicameral bone cysts to make decisionsabout control and care: 


Ask your doctor about various treatment options related to unicameral bone cysts. Little knowledge is dangerous. Therefore, more confidence in understanding and making decisions about treatment options will be there with you. So you should always learn more about the disease.


Ask the health care team for guidance if your child has cancer. Therefore, get more and more information for appropriately caring for the patient.


Be close to your friends and family:

A close and strong relationship with your family and friends is necessary. It will help you deal with unicameral bone cysts.


You need practical support, moral support from your friends and relatives. Thus, someone should be there for you to look after the family. Emotional support from them is going to matter most. Thus, a healthy and happy person will ultimately efficiently fight the disease.


Prepare for your appointment


You are likely to start making an appointment with your primary care doctor if some signs and symptoms worry you. Ask for a referral to an experienced specialist if your doctor suspects unicameral bone cysts.


A team of specialists typically can treat. For instance;

Orthopedic unicameral bone cysts surgeons or orthopedic oncologists who have specialization in operating bone cancers.

Doctors who have a specialization in treating cancers with systemic medications or chemotherapy.

Pathologists diagnose the specific type of cancer by analyzing a tissue.

Rehabilitation specialists who after surgery help in the recovery of a tumor.


What you should expect from your doctor:


You will face several questions from your doctor. Thus, you should be ready to answer these. So, give more time to your doctor to address them. Your doctor may ask;


What signs and symptoms concern you more?


Have your symptoms been occasional or continuous?


When did you start to notice the symptoms?

The severity of your symptoms?


Is there anything that improves your symptoms?


Is there anything that worsens your symptoms?


Do you have any family or personal history of cancer?