OSTEOID OSTEOMA: SYMPTOMS, CAUSES AND TREATMENT - ANATOMY AND PHYSIOLOGY - 2025

The osteoid osteoma is one of the primary neoplasms of the bone tissue. It is benign, self-limited, without a tendency to malignant. This neoplasm can appear in any type of bone tissue, but has a predilection for the appearance in long bones such as the femur. It is usually asymptomatic; however, its most characteristic symptom is pain.

The importance of knowing about this neoplasm is that its early detection can avoid complications due to compression of continuous tissues, destruction of bone tissue by crushing, aesthetic deformation with psychological repercussions and compressive symptoms, such as pain that generates a progressive functional limitation.

The femur is one of the bones most prone to osteoid osteoma

Causes

The causes behind the formation of this benign tumor correspond to an active and progressive increase in bone formation, which is encapsulated to form a small tumor.

The reason behind this increase in bone production is not fully understood and it is thought that it may be related to bone regeneration after minor trauma that does not cause obvious bone damage, but bone inflammation.

Due to this bone inflammation, the blood vessels undergo hemodynamic changes in terms of caliber and arteriolar flow, increasing them considerably in order to feed the tissues to repair the damage.

This causes the osteoblasts, which are precursor cells of mature bone, to multiply rapidly, forming a tumor structure that presses on the underlying structures, producing encapsulation. This encapsulation is what allows the osteoma to limit itself.

epidemiology

Osteoid osteoma is more common in men in a ratio of 2: 1 compared to women. On the other hand, the most affected age group is <25 years, so that it appears with greater probability in young adults and children.

The most common place of appearance is the femur and, in general, the lower limbs. Bones such as the fibula and tibia are also common sites of proliferation; however, it can appear in any type of bone, such as the skull, clavicles, phalanges of the upper limb, etc.

characteristics

They are circular to oval lesions, usually small in size, approximately between one and five centimeters. Its growth is self-limited.

They are characterized by having an internal area called the nidus or nest, where a large amount of osteoid tissue is concentrated and which is highly vascular. This conformation induces sclerosis and thickening of the surrounding bone.

Classification

There are three types of osteoid osteoma known today:

Spongy Osteoma

It is found within the medulla; therefore, it has an intramedullary location. This results in a delay in diagnosis.

Cortical osteoid osteoma

It is the most common of the three types. It is characterized because its nest is well defined in the cortex of the bone.

Subperiosteal osteoid osteoma

It is characterized because it generates a great erosion in the cortical bone.

Symptoms

The main clinical picture is asymptomatic, since osteomas are generally small in size and their symptoms will manifest depending on their location.

The appearance of these tumors entails complications that can make life difficult for the individual, with psychological and biological repercussions. Among these we can mention:

- Acute pain, which is caused by compression of neighboring structures such as nerves or muscles.

- Aesthetic deformity. Depending on its location, the osteoid osteoma could cause aesthetic discomfort with psychological repercussions on the individual.

- Functional limitation. If found in places such as joints, the osteoid osteoma could cause a malfunction of the joint, and can even lead to functional disability.

- In children, the osteoid osteoma could be found in the growth cartilage itself, causing growth retardation or bone dysgenesis.

Diagnostics

Clinical

In general, the first approach to diagnosis should be made with a correct anamnesis, questioning family history, because it has been shown that there is a certain genetic factor associated with the appearance of these lesions.

Interrogation with findings of intense pain, of sudden onset that increases at night, could also guide the diagnosis.

In turn, being a highly vascular tumor, vasodilator substances could induce the appearance of pain when consuming them, such as alcohol.

The physical examination in cortical or subperiosteal osteoid osteomas that have grown sufficiently to be palpable also points to this pathology.

Imaging

X-rays of the involved bones will show:

- Oval or rounded image.

- Radiopaca.

- Thin radiolucent edges.

- Homogeneous and dense content (nidus).

Computerized axial tomography is also useful to diagnose this pathology, unlike magnetic resonance imaging.

Differential

The main differential diagnosis should be made with osteoblastoma, which is another common benign neoplasm but with the difference that the latter is much larger and does not produce as intense a bone reaction as does osteoid osteoma.

Other pathologies from which the osteoid osteoma must be differentiated are osteosarcoma, stress fractures, myelomas, osteomyelitis, bone islets, etc.

Treatment

Usually, due to the benign nature of this pathology and its usual asymptomatic presentation, no treatment is given. In case of symptoms, it can be treated medically with non-steroidal anti-inflammatory drugs (NSAIDs) to reduce pain, awaiting its reabsorption by the body.

In case it causes plastic deformations, functional limitation or that they are large, it is necessary to perform a surgical intervention.

To make a correct resection of the osteoid osteoma, it requires a special staining using a drug called tetracycline, which gives it a yellowish coloration that facilitates its delimitation for its subsequent surgical resection.

Another way to locate and remove it is through a resection guided by computerized axial tomography. It should be noted that this last process is performed surgically to extract the nidus and thus eliminate the vascularization of the osteoma, increasing its resorption rate.

References

1. Osteoid osteoma. Recovered from: arturomahiques.com
2. Gomez C. Ostema osteoid. Recovered from: medigraphic.com
3. Bosch Enrique. Osteoid Osteoma: Percutaneous resection guided by computed tomography. Recovered from: scielo.conicyt.cl
4. Osteoid osteoma. Recovered from: bibing.us.es
5. Bone tumors diagnostic and therapeutic approach. Recovered from: ucm.es