enchondroma

Generality

The enchondroma is a benign-type bone tumor that originates from a cartilage cell in the bone marrow.

Like any tumor, even the enchondroma arises due to some mutational events, which alter cellular DNA. At the moment, despite the numerous studies on the subject, the precise factors that trigger the aforementioned mutational events are not clear.

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Generally, the enchondroma is characterized by the presence of a cyst which, in some patients, is responsible for fractures and bone deformities. Sometimes, this cyst assumes the characteristics of a malign neoplasm, becoming, to be precise, a chondrosarcoma.

For a correct diagnosis of achondroma, the following are fundamental: physical examination, medical history, diagnostic imaging tests and tumor biopsy.

If the enchondroma is asymptomatic, it does not require any treatment; if it is symptomatic, surgery is required.

Short review of what a tumor is

In medicine, the terms tumor and neoplasia identify a mass of very active cells, able to divide and grow uncontrollably.

We speak of a benign tumor when the growth of cell mass is not infiltrative (that is, it does not invade the surrounding tissues) and even metastasizing.
There is talk of a malignant tumor when the abnormal cell mass has the ability to grow very quickly and spread to the surrounding tissues and the rest of the body.
The terms malignant tumor, cancer and malignant neoplasia are to be considered synonymous.

What is the enchondroma?

The enchondroma is a benign bone tumor that originates in a cartilaginous tissue cell present within the bone marrow .

According to another definition, the enchondroma is a benign bone tumor, originating in the medullary cartilage; the marrow cartilage is nothing but the cartilaginous tissue located inside the bone marrow.

At the skeletal level, the most common sites of onset of the enchondroma are: the bones of the hand, the bones of the feet, the femur (thigh bone), the tibia (one of the two bones of the leg) and the humerus (bone of the arm).

In most cases, the enchondroma appears as a single tumor; more rarely, it is characterized by the presence of multiple tumor masses.

According to some medical surveys, 50% of the enchondromes would affect the bones of the hands and feet.

The remaining percentage of cases would be divided into enchondromes involving the femur, tibia and humerus.

WHAT IS THE BONE MARROW?

Bone marrow is a soft tissue, present in the internal cavity of some bones (femur, humerus, vertebrae, etc.). Its job is to produce blood cells, namely red blood cells (erythrocytes), white blood cells (leukocytes) and platelets (thrombocytes).

The process of producing blood cells is called hematopoiesis .

Epidemiology

The enchondroma is a neoplasm that mainly affects the population aged between 10 and 20 years; in other words, it is more common in adolescents and young adults.

According to some statistical surveys, the enchondroma would represent less than 5% of all bone tumors and just over 17% of all benign-type bone tumors.

Causes

Most tumors - including encondroma - arise due to genetic DNA mutations, which alter cellular processes of growth, division and death.

The tumor cells grow and divide abnormally, at a faster rate than normal, so that, for these reasons, the experts tend to define them with the terminology of " mad cells ".

WHAT IS IN AN ENCONDROMA?

Some researchers believe that the enchondroma derives from an alteration of the cartilage growth process, located at the ends of the bones; other scholars, however, are of the opinion that the enchondroma is the consequence of a persistent and anomalous growth of the embryonic cartilage.

WHAT FACTORS FAVOR THE DNA MUTATIONS?

Physicians have not yet discovered precisely what factors and circumstances favor DNA mutations that cause the enchondroma episodes.

The most recent studies have ruled out that the onset of enchondromas depends on some of the classic risk factors for bone cancer, such as:

Exposure to ionizing radiation
Exposure to certain pharmacological / chemical substances.

Symptoms and Complications

To learn more: Symptoms Encondroma

The cellular mass that characterizes the episodes of encondroma is a cartilaginous cyst, located within the bone marrow.

In general, the enchondroma is an asymptomatic neoplasm, ie it does not cause symptoms; instead it tends to be responsible for a specific symptomatology when the tumor mass arises on a bone of the hand or foot, or when the neoplasm presents itself with multiple masses.

As regards the symptoms in the cases just mentioned, this consists of:

Abnormal bone weakening;
Deformation of the affected bone or bones;
Easy to break.

SPECIAL ASSOCIATIONS

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The enchondroma is often a solitary tumor.

However, in some rare cases, it is possible that it appears in association with two particular medical conditions, known as Ollier syndrome and Maffucci syndrome .

Ollier syndrome: also known as enchondromatosis, it is characterized by the continuous formation of enchondromes in different parts of the body. Usually, he appears at a young age.
The formation of enchondromes stops after completion of skeletal maturation.
People who suffer from Ollier syndrome have a particular propensity for bone fractures and, in fractured bones, have severe deformities.
Ollier syndrome affects about one individual every 100, 000 people.
Maffucci syndrome: is a condition characterized by the simultaneous presence of multiple encondromes and multiple hemangiomas. Sometimes, it also involves the onset of multiple lymphangiomas.
Generally, Maffucci syndrome occurs during adolescence or the years of puberty; mainly affects the phalanges of the hand, causing deformation and an unusual tendency to fracture. Rarely, it affects the phalanges of the feet and other skeletal districts.

COMPLICATIONS

The enchondroma is a benign neoplasm which, following further mutational DNA processes, can however become a malignant neoplasm . As a rule, the type of malignant tumor in which the enchondroma is converted is chondrosarcoma .

Fortunately, the conversion of an encondroma into a chondrosarcoma is an uncommon event; according to some statistical surveys, it would occur in 5% of cases.

Unlike the enchondroma, chondrosarcoma is responsible for various symptoms, including:

Bone or bone pain affected;
More intense pain than usual when waking up from sleep at night or after particular activities;
Swelling at the level of the area presenting the tumor mass;
Considerable tendency to bone fractures.

Chondrosarcoma is a malignant bone tumor that affects the cartilage tissue located at the end of the bones of the skeleton.

Diagnosis

Almost always lacking a symptomatology, the enchondroma is a condition that doctors almost always diagnose by chance, during an X-ray examination practiced for other reasons (eg: in the case of a bone injury or the presence of arthritis).

To know the characteristics of an enchondroma and to understand its actual danger, the following are fundamental: physical examination, medical history, further diagnostic imaging tests (in addition to X-rays) and tumor biopsy.

DIAGNOSTICS FOR IMAGES

Diagnostic imaging tests serve primarily to identify the exact location of the tumor mass.

Among the diagnostic tests by image useful in case of bone cancer, include:

TAC (or Computerized Axial Tomography ).
Characteristics: it involves the patient's exposure to a certain amount of ionizing radiation, therefore it is slightly invasive.
Nuclear magnetic resonance ( RMN ).
Characteristics: it does not involve the patient's exposure to radiation, so it is not invasive.
Bone scintigraphy .
Characteristics: it involves the use of a radioactive liquid, therefore it is invasive.

TUMOR BIOPSY

A tumor biopsy consists of the collection and histological analysis, in the laboratory, of a sample of cells from the tumor mass.

It is the most appropriate test to define the main characteristics of an enchondroma, from the precise histology to the degree of aggressiveness.

Performed under local or general anesthesia, the collection of cells from an enchondroma can take place in at least two different ways: by means of a needle (needle biopsy) or by means of a scalpel ("open" biopsy).

To learn more about this topic, readers can consult the article here.

Importance of tumor biopsy in the presence of a suspected chondrosarcoma

At a visual examination of the images provided by an MRI or a CT scan, the enchondroma and a low grade chondrosarcoma have very similar characteristics. This complicates their recognition.

The only way to understand the exact nature of the tumor mass is to subject it to a biopsy.

Treatment

If it lacks symptomatology and maintains its benign nature, the enchondroma does not require any treatment. In the aforementioned situations, the only indication of the doctors consists in the recommendation to keep under observation and periodically monitor the tumor mass, through diagnostic imaging tests (X-rays and other).

WHEN IS A TREATMENT NEEDED?

The enchondroma requires a specific treatment, when it is symptomatic (eg: due to fractures, deformity, bone weakness, etc.) or when it changes into a malignant neoplasm.

WHAT IS THE TREATMENT?

The treatment of an enchondroma is surgical and consists, first, in the so-called curettage of the tumor mass and, subsequently, in the bone transplant :

The scraping operation is an operation that the surgeon can practice only when the affected bone is intact. Therefore, if there are fractures at the time of diagnosis of an enchondroma, it is necessary to wait for their recovery.
Bone transplantation involves taking a piece of healthy bone tissue from a part of the body of the same patient and grafting it into the affected area (autologous transplant or autograft). It serves to reinforce the bone just scraped.
Sometimes, the transplant may be of the allogeneic type, ie the collection involves a compatible donor.