What is Osteoblastoma? What Are Its Symptoms? How Is It Diagnosed and Treated?

Osteoblastoma is a rare condition that accounts for only about 3% of all benign bone tumors. It is generally not cancer, but it can cause pain and swelling. It is particularly more common in males between the ages of 10 and 30, and 2 out of every 5 cases occur around the spine. In this article, we have compiled topics such as what osteoblastoma is, what osteoblastoma symptoms are, how osteoblastoma is diagnosed, osteoblastoma treatment options, and the causes of osteoblastoma for you.

What is Osteoblastoma?

Osteoblastoma is a type of benign, bone-forming tumor. It attacks healthy bone tissue, creating a new tissue called osteoid. This osteoid material grows around the healthy tissue but is weaker than normal bone tissue.

Therefore, it makes your bones more vulnerable to fractures. In terms of size, osteoblastoma is larger than an osteoid osteoma. According to the World Health Organization definition, tumors measuring 2 cm and above are classified as osteoblastoma. In cases, the tumor size may vary between 1.3-10 cm.

Although osteoblastoma looks histologically similar to osteoid osteoma, it behaves more aggressively from a clinical and radiological standpoint. The disease usually progresses slowly. It may not show obvious signs in the early period, but pain and soft tissue swelling appear in the advanced period.

Is Osteoblastoma Cancer?

Osteoblastoma is almost always benign and is not cancer. It is not expected to spread to distant parts of your body. However, there is a possibility of recurrence at the site where it is located.

Despite this, it has a more aggressive form called aggressive osteoblastoma. This type appears at older ages and is more destructive in the region where it settles. The risk of recurrence is higher compared to the classic type.

Although very rare, there is a risk of malignant transformation. In some cases, instances progressing to osteosarcoma have been reported. Because residual tumors carry the risk of turning into a malignant tumor, patients require close follow-up.

Where Does Osteoblastoma Form?

Osteoblastoma can form in any bone, but it has a predilection for certain areas. 2 out of every 5 osteoblastomas develop around the spine. The spine and long bones are the most common sites.

Approximately one-third of osteoblastomas are spinal-localized. The posterior elements of the spine are the most affected parts. While it can involve all vertebrae, the lumbar vertebrae are involved more frequently. In the cervical region, the body of the spine is affected more.

Additionally, osteoblastoma can develop in the following regions:

Hands

Feet

Legs (especially the femur)

Lower jawbone (mandible)

In long bones, it is usually located in the metaphyseal region. Diaphyseal and epiphyseal involvement can be seen rarely. It frequently shows intramedullary eccentric or cortical-based localization.

Who Can Get Osteoblastoma?

Although anyone can get osteoblastoma, it most frequently occurs in individuals between 10 and 30 years of age. 80% of cases are seen before the age of 30. The most common period is the second decade.

There are more than twice as many males with osteoblastoma as females. The average age in osteoblastoma cases has been reported as 15 years. The childhood and young adult age group is the most affected segment.

Aggressive osteoblastoma is encountered at older ages. It is usually diagnosed in the 30-40 age range and is of larger dimensions.

How Common Is Osteoblastoma?

Osteoblastoma is a very rare condition. It accounts for only about 3% of all benign bone tumor diagnoses. It makes up 0.5-2% of all primary bone tumors and 3-6% of benign bone tumors.

These figures show how infrequently encountered a bone tumor osteoblastoma is. Accordingly, only a few out of thousands of people encounter this tumor.

What Are the Symptoms of Osteoblastoma?

General Symptoms

Pain is the most important symptom of osteoblastoma. This pain, which appears in the affected area, continues for a long time and shows a gradual increase. The pain intensity may increase at night, but it is not in the form of typical night pain as in osteoid osteoma.

Unlike osteoid osteoma, pain relievers are not very effective. Its response to pain relievers is less than that of osteoid osteoma. Waking up from pain at night is also not as prominent as it is in osteoid osteoma.

The severity and degree of pain do not change with position or movement. This creates a challenging process for patients. The tumor can grow and put pressure on surrounding tissues, causing restricted movement.

Other general symptoms include local swelling, tenderness, and loss of function. The disease progresses slowly and may not give obvious signs in the early period.

Symptoms of Osteoblastoma in the Spine

In spine-localized osteoblastomas, symptoms are more complex. Neurological symptoms are frequently seen in vertebral involvement, reaching rates of up to 40%. Neurological symptoms due to nerve compression can develop in large tumors.

Osteoblastoma in the spine can cause the following symptoms:

Back pain

Muscle spasms

Numbness

Scoliosis (irregular curvature of the spine)

Weakness

When it settles in the posterior elements of the spine, it can cause pathological scoliosis due to pain. It may present with painful scoliosis and torticollis (contraction of neck muscles). Spinal involvement constitutes one of the rare causes of scoliosis.

Neurological deficits at varying rates can be seen in thoracic region lesions. Although the tumor generally does not grow toward the spinal canal, it can put pressure on spinal structures. This situation significantly affects the patient's daily quality of life.

Symptoms of Osteoblastoma in the Extremities

Osteoblastoma in the hands or feet causes swelling or pain. The pain usually worsens at night. Similarly, involvements in long bones also create local pain and swelling.

Tumors forming in the extremities can lead to movement restriction. In the event of nerve involvement, a feeling of numbness appears. Tenderness is prominent in the affected area, and pain increases with touch.

Although symptoms vary depending on the location of the lesion, it is typical for symptoms to show a gradual increase. Since the disease progresses slowly, some patients may ignore the symptoms for a long time.

How Is Osteoblastoma Diagnosed?

Physical Examination

When diagnosing osteoblastoma, your doctor will first ask questions about your symptoms. Issues such as when the pain started, where it is concentrated, and how it affects your daily activities are evaluated. The area where you experience pain is carefully examined.

During the physical evaluation, your range of motion is tested. Your doctor looks at whether you can perform normal movements of the affected joint or bone. Tender points are determined via palpation. The presence of swelling or deformity is checked.

If there is spinal involvement, a neurological examination is performed. Muscle strength, reflexes, and sensory evaluation are parts of this examination. Scoliosis or posture disorders may emerge during the physical examination.

Imaging Tests

Radiological evaluation is of vital importance in diagnosing osteoblastoma. An X-ray is taken to look at your bones. However, the lesion may not always be clearly seen on an X-ray. Therefore, additional imaging methods are needed.

The dimensions and exact localization of the lesion are determined via tomography and MRI. CT scanning is useful to precisely define the location of the tumor and the extent of bone involvement. The nidus, surrounding sclerotic changes, and calcification areas can be clearly evaluated.

On MRI imaging, the lesion has low signals on T1-weighted images. It is observed as heterogeneous hyperintense on STIR and T2-weighted images. The ossified matrix is seen as low-signal areas in both sequences. MRI may exaggerate the size of the lesion due to local inflammation and edema. Nevertheless, it helps determine soft tissue changes as well as the effect of the tumor on neighboring tissue.

The presence of bone marrow edema and edematous signal changes in neighboring soft tissues is frequently an expected situation. In radiological evaluation, it appears in the form of lytic lesions having a thin border. Intra-lesional calcification may accompany it. Especially in vertebral localization, tomography is guiding in surgical planning.

Biopsy

Definite diagnosis is made with a bone biopsy. Doctors almost always use a biopsy to diagnose osteoblastoma. In a biopsy, a small tissue sample is taken from the tumor. The laboratory examines the tissue to look for signs of osteoblastoma and rule out other conditions such as cancer.

A biopsy is the procedure of taking a tissue sample from the body. The obtained tissue samples are examined in the laboratory using special methods. Histological evaluation is of great importance for making a definitive diagnosis and ruling out osteosarcoma.

A bone biopsy can be performed using closed or open methods. In a closed bone biopsy, the bone tissue is reached without making an incision on the skin using a special needle. In an open bone biopsy, an incision is made on the skin, and a sample is taken under direct visualization from the tissue thought to be diseased.

In histopathological examination, osteoid tissue with increased osteoblasts and osteoclasts and without mitotic or atypical structures is seen. These findings support the diagnosis of benign osteoblastoma.

How Is Osteoblastoma Treated?

Surgical Treatment Methods

When planning osteoblastoma treatment, factors such as the patient's age, tumor size, and location are taken into consideration. Surgical intervention is the most effective method in osteoblastoma treatment. Complete removal of the tumor reduces the recurrence rate.

Whether surgery is appropriate depends on the size and location of the tumor. In osteoblastoma surgery, the entire tumor must be removed. Healthy bone tissue must be completely cleared of the tumor. If the entire tumor is not removed, the probability of local recurrence is high.

The risk of recurrence after surgery has been reported at a rate of 10-20%. Therefore, patients should be followed closely at specific intervals. En bloc resection is aimed, but if complete resection is not possible due to the anatomical location of the lesion, intralesional curettage can be applied.

Marginal Resection

Marginal resection is the removal of the portion of the bone containing the osteoblastoma. In this method, the outer surface of the pathological tissue is removed without entering the tumor. The tumor is removed in one piece together with its capsule.

It can be applied in different ways with factors such as the location, size, and contact of the tumor with tissue. Local excision is preferred in cases where there is a possibility of the tumor spreading to surrounding tissues. A certain amount of healthy tissue next to the tumor is also removed to prevent spreading.

Open, laparoscopic, or robotic surgery may be preferred in the application of marginal resection. Open surgery is used for cleaning large tumors. Minimally invasive methods leave minimal damage to the body through small incisions.

Curettage and Bone Graft

Intralesional curettage is applied in the treatment of osteoblastoma. In this method, the tumor is cleaned by scraping from the inside. The application of local adjuvants after curettage is recommended to reduce the probability of recurrence in tumors in appropriate localizations.

Substances such as cautery, liquid phenol, or alcohol are used as local adjuvants. These applications ensure the complete destruction of tumor cells. Broad curettage and graft placement are performed. Resection is applied in aggressive cases.

The resulting cavity can be filled with bone cement. Alternatively, after the tumor is scraped, the region is refilled with a bone graft taken from a donor or another part of the body. Fixation can be applied when necessary in terms of stability.

Spinal Fusion

After removing a spinal osteoblastoma, it is necessary to realign and support the spine with a bone graft. Sometimes fixation is done with pins or rods. Treatment consists of resection and resulting fusion if spinal instability is encountered.

Since pain and increased size in the spine can cause bone destruction, neurological damage, or spine deformity with instability, it is treated surgically. During the surgery of a tumor located in the cervical region, care must be taken since damage to the vertebral artery can lead to serious consequences.

Safer resection can be made possible through the use of advanced techniques such as intraoperative navigation or CT. Since osteoblastomas are vascular tumors, blood loss that may occur can be reduced with peri-operative embolization.

Other Treatment Options

Radiotherapy generally gives a limited response in the treatment of osteoblastomas. Despite this, radiotherapy can be performed in patients who cannot undergo complete resection. If the tumor is very large, radiation therapy can be used to shrink the tumor.

There is no definitive consensus regarding late sarcomatous changes after the use of adjuvant radiotherapy. Analgesics and anti-inflammatory drugs can be used to bring pain under control. Supportive treatments that contribute to the general health of patients can be applied.

The combined or single use of radiotherapy and chemotherapy has been reported in unresectable or recurrent osteoblastoma cases. In very rare situations such as the tumor being cancerous, other cancer treatments such as chemotherapy can be used. Although not widely used, the use of radiofrequency ablation in treatment is out of the question.

Frequently Asked Questions About Osteoblastoma

What Are the Causes of Osteoblastoma?

Patients frequently wonder what causes osteoblastoma. Experts do not know what causes osteoblastoma. A definitive cause has not yet been determined.

Whether genetic factors play a role is being investigated. Despite this, a familial transmission or hereditary connection has not been proven. The effect of environmental factors is also not clear.

It is known that the tumor originates from the excessive proliferation of osteoblast cells. However, exactly what triggers this proliferation remains uncertain. Its relationship with external factors such as trauma or infection could not be demonstrated.

How Is Osteoblastoma Prevented?

Since experts do not know what causes osteoblastoma, there is no way to prevent it. Therefore, there is no known prevention strategy that will stop the development of osteoblastoma.

A healthy lifestyle supports bone health, but there is no evidence that it will prevent the formation of osteoblastoma. Certain foods or exercises do not have a protective effect. Regular screening programs are also not recommended.

Early diagnosis is important. If you notice persistent pain or swelling in your bones, you need to consult your doctor. Bone pain occurring especially at a young age must be taken seriously.

Does Osteoblastoma Recur?

Osteoblastoma can return after treatment. 1 in every 4 people gets osteoblastoma again. The recurrence rate has been reported between 10-20% in different studies.

The probability of the tumor returning depends on many factors. Whether the doctor could remove the entire tumor without harming other tissues is important. Failure to remove the entire tumor during surgery increases the risk of recurrence.

If the doctor suspects the tumor may return, regular imaging scans may be needed to monitor the area. Similarly, patients should be checked at specific intervals after surgery. Radiological follow-up usually continues for years.

The localization site of the tumor also affects the recurrence risk. Complete cleaning can be harder in tumors in complex anatomical regions like the spine. The probability of recurrence increases in lesions that have spilled into soft tissue.

How Is the Course of Osteoblastoma?

Osteoblastoma generally has a good course. Most people recover after surgery to remove the tumor. The prognosis is generally favorable, and patients return to their normal lives.

In some cases, tumors can grow back, but these are not cancer and generally do not cause serious symptoms. Recurrent tumors can be treated surgically again. Quality of life improves in most patients after surgery.

Pain control is successfully achieved. Patients with movement restriction recover with physical therapy. Even in spine-localized tumors, neurological problems usually improve after surgery.

Can Osteoblastoma Be Aggressive?

Some osteoblastoma types are aggressive. Such tumors have a high probability of growing back after being removed. Additionally, aggressive osteoblastoma appears at older ages and is usually diagnosed in the 30-40 age range.

Aggressive forms are more destructive in the region where they settle, and the recurrence risk is higher. They are seen in larger dimensions. They put more pressure on surrounding tissues and cause bone destruction.

Despite this, osteoblastoma does not spread to other parts of the body. It does not metastasize, and this feature distinguishes it from cancer. Even if aggressive, distant organ involvement is not expected.

Although very rare, aggressive forms carry the risk of turning into osteosarcoma. Therefore, regular follow-up of patients is of great importance. Early intervention prevents complications and increases treatment success.

Osteoblastoma in Summary

Osteoblastoma is a rare benign bone tumor. It usually appears in young people and is most frequently localized around the spine. When you notice symptoms such as pain and swelling, you should definitely consult your doctor.

Early diagnosis increases treatment success. With surgical intervention, most patients fully recover and return to their normal lives. Therefore, complete removal of the tumor prevents its recurrence.

Regular follow-up after treatment is important. In some cases, the tumor may return, but retreatment is possible even in this case. If you have persistent pain in your bones, get expert support without wasting time.