A solitary bone cyst belongs to the so-called cancer-like bone changes. It appears as a fluid-filled tumor that develops inside the bone and may be asymptomatic for many years, and is most often detected by chance. what are the causes and symptoms of a solitary bone cyst? How is the treatment going?

Solitary bone cystmost often develops in children and young adults - 80 percent of patients are up to the age of 20, and the peak incidence is estimated at between 4 and 10 years of age . It is estimated that it occurs two to three times more often in the male sex. Adults are less frequently affected by the disease.

How is a solitary bone cyst formed?

There are several theories of the formation of a solitary bone cyst, and so far no clear cause has been established. One of them may be processes that already take place in the intrauterine life. During the development of the fetus, a small amount of synovial tissue may enter the bone and remain there, forming a cyst. Such fluid may also enter the bones as a result of trauma or as a result of trauma due to abnormal venous outflow in the bone during rapid growth. Another cause may be abnormal ossification processes in a growing child. Over the years, the cyst inside the bone grows bigger and the pressure inside it keeps increasing.

Where is a solitary bone cyst most often located?

Solitary bone cysts can be found in various locations, but typical places of its occurrence are the proximal part of the humerus, femur or tibia. To a lesser extent, mainly in adults, the hip, heel, or ankle bone may be involved.

Types of solitary bone cyst

There are two types of solitary bone cysts. The active form is found mainly in children under the age of ten. It is characterized by constant growth, it can occupy the entire epiphysis of the bone, leading to its fracture. The second form, inactive, is characteristic mainly for patients over the age of twelve. Its growth is not so aggressive, it sometimes heals spontaneously and rarely leads to fractures.

Solitary bone cyst - what are the symptoms?

A solitary bone cyst is an osteolytic lesion. That is, as it growsdestroys the surrounding bone tissue. The disease is usually asymptomatic. Some people may experience pain, swelling or stiffness in the surrounding joints. Most often, however, a solitary bone cyst is detected accidentally, as a result of pathological fractures that cause it to grow for many years. Pathological fractures are those that occur as a result of minor trauma. Under physiological conditions, such an injury would not lead to bone damage, but osteolytic changes cause the tissue to be weakened so much that even minor overloads lead to its fracture.

How is a solitary bone cyst diagnosed?

Due to the fact that the disease is asymptomatic for many years, diagnosis usually begins when a pathological fracture occurs. Most often, an X-ray is sufficient to reveal a cyst inside the distended bone. Computed tomography or magnetic resonance imaging does not contribute much more to the diagnosis of a solitary bone cyst, but they are helpful in the differential diagnosis because they can eliminate or confirm other conditions that may appear to resemble a benign bone cyst.

Solitary bone cyst: treatment methods

There are several treatments available for solitary bone cysts. Intervention is not usually required because the cyst is small, is not likely to fracture, and does not deform the bone. However, when the cyst poses a risk to the patient, appropriate management should be implemented.

The most common treatment is surgical curettage of the tumor. The space after the cyst is filled with cancellous bone grafts, which may come from the patient or from another donor. Additionally, the patient's bone marrow or other growth factors obtained from his blood are administered. In addition to grafts in the cavity of the removed cyst, other replacement materials can be given, for example hydroxyapatite or bioactive ceramics. All these elements are intended to rebuild the damaged bone.

Other methods of treatment, unfortunately much less effective, are puncture of the cyst and, after removal of the fluid, administration of glucocorticosteroids into its interior, which should cause the tissues to heal. In addition, the cyst is drilled with a drill, which may contribute to its spontaneous atresia.

With what should a solitary bone cyst be differentiated?

The clinical picture of a solitary bone cyst may resemble other diseases that develop within long bones, such as:

  • fibrous bone dysplasia
  • aneurysmal bone cyst
  • eosinophilic granuloma
  • giant cell tumor -more common in the elderly, it is usually located around the articular surfaces
  • non-ossifying fibroma - located mainly in the cortex of the bone, more outside than the solitary bone cyst

Solitary bone cyst: prognosis

Solitary bone cyst is a benign lesion, but in 30-100% it shows a high recurrence tendency. In some cases, the cyst may become malignant, leading to the development of osteosarcoma or fibrosarcoma, and the disease should be effectively and consistently treated and monitored regularly.

Category:

Spine, bones, joints