Chondroblastoma: A gentle cancer!

Chondroblastoma is a rare disease that, unlike its name, does not appear in cartilage, but usually occurs in bone. With a slow pathological progression, few symptoms, as well as a high survival rate in most cases, chondrosarcoma is considered less aggressive than other cancers.

However, when the disease has progressed for a long time, the patient's survival rate is greatly reduced. Let's learn together to recognize and have certain concepts about cartilage cancer.

content

• 1. Introduction
• 2. Presence of cartilage cancer?
• 3. Causes and risk of cartilage cancer?
• 4. Classification and manifestations of cartilage cancer 
• 5. Diagnosis of Cartilage Cancer
• 6. Cartilage cancer treatment
• 7. Survival of patients with cartilage cancer
• 8. Conclusion

1. Introduction

Chondrosarcoma is also known as chondroblastoma. To explain the term "chondrocyte cancer", you need to clarify each of the following issues:

What is cancer?

Cancer is a term that describes certain cells of the body that have the ability to continuously grow and divide. These cells are not under the control of the body. Unlike normal cells, which will die by themselves in old age, cancer cells can in some respects be considered as immortal cells (never old).

Therefore, from a cancer cell, it can develop into a tumor on its own, as well as the tumor will grow on its own. The next possibility is that the cancer can enter the blood vessels to reach other organs. This phenomenon is called metastasis.

The invasion, uncontrolled growth of cancer will compress and disrupt the function of the organ it goes to. Cancer also requires the body to supply blood and nutrients to nourish them. From there, cancer takes over the life of nearby organs.

What are chondrocytes?

There are two types of cells in cartilage: chondrocytes and chondrocytes. Chondrocytes are the cells that secrete most of the major components of cartilage.

After chondrocytes form most of the structures in the cartilage, some chondrocytes turn into chondrocytes on their own. Chondrocytes mature from mesenchymal cells – a type of pluripotent cell that can develop into many different cell types.

What is the nature of chondroblastoma?

Chondroblastoma is a group of malignant cells shaped like chondrocytes, carrying some of the functions of chondrocytes. But in fact: this type of cancer is not caused by malignant chondrocytes. Chondroblastoma has a true origin in the malignancy of mesenchymal cells.

Mesenchymal cells in bone marrow

These are pluripotent stem cells that have the ability to self-replicate and differentiate (grow) into cells with specific functions such as fat, bone, and cartilage. Thus, mesenchymal cells are the precursors of chondrocytes; Chondrocytes are the precursors of chondrocytes. In other words, Differentiation is a maturation process that develops from one cell type to another.

Thus, chondroblastoma originates from malignant mesenchymal cells. These cells then differentiate (grow) into malignant chondrocytes!!!. The mechanism of this phenomenon is still unclear.

Center: General mesenchymal cells. The group of mesenchymal cells in the bone marrow can differentiate into bone and cartilage.

2. Presence of cartilage cancer?

Like other malignancies of bone, this is a rare cancer. Cartilage and bone cancers in general account for about 1% of all cancer cases worldwide. In this 1%, chondroblastoma is the second most common malignancy. The incidence of chondrosarcoma is about 3 – 4 persons per 100,000 per year.

3. Causes and risk of cartilage cancer?

Gene mutations are the main cause. Although chondrosarcoma can occur at any age, it is most common in middle-aged to elderly people.

Ollier disease and Mafucci syndrome are diseases that cause cartilage tumors to appear on the body. These lesions sometimes turn malignant after a certain time.

Left: Chondrosarcoma on radiograph of the arm. Right: Cartilage cancer image when surgically removed

4. Classification and manifestations of cartilage cancer 

Cartilage cancer classification

Because it is derived from mesenchymal cells - which exist in the bone marrow. So, the chondrocyte cancer is located in the bone. As a form of cancer that is a transformation from one cell type to another, chondriasis can have many different shapes. Chondroblastic cancers are classified based on the degree of complete differentiation from mesenchymal cells to chondrocytes. In it, people are divided into:

• Good differentiation. This type has a microscopic appearance that closely resembles chondrocytes. Differentiation occurs almost completely.
• Poor differentiation. This form has a very similar appearance to mesothelioma, a bit like chondrocytes. 
• Reverse differentiated: Including poorly differentiated cells + some well differentiated cells.

Figure A: X-ray of cartilaginous carcinoma in the upper humerus. B, C: Cartilage cancer on MRI

Manifestations of cartilage cancer

Often, bone and cartilage cancers have no symptoms because the disease progresses very slowly. Bone and cartilage cancer is detected in the following cases:

• Fracture. Patients with bone and cartilage cancer are more prone to fracture than the general population. Even a minor injury can cause a patient to break a bone.
• Pain and swelling in the bone with cancer. The pain can come and go on its own, and the pain from bone and cartilage cancer usually gets worse over the course of several weeks to months. The pain is sometimes worse at night and with exercise. Some people may also see or feel a lump on the bone.
• Accidentally discovered on XQ film. Due to some other diseases (heart, lung) or craniocerebral or periodic X-ray that can detect chondroblastoma.
• Double vision, headache. Patients can have this manifestation when cancer of the bone, cartilage located in the skull bone at the back of the head.

Illustrate what a patient with diplopia can see

Common sites of cartilage cancer

• Pelvis.
• Ribs.
• Long bones (femur, humerus).
• Sometimes it can be seen in the skull and spine.

The specific location of cartilage cancer on bone is usually in the bone marrow region (location of mesenchymal cells). However, for secondary cartilage cancer, it can appear anywhere on the bone.

Assess the stage of cartilage cancer

Based on the invasion of the cancer to which part of the bone, whether it has entered the bloodstream to other organs or not, people will be divided into different stages.

5. Diagnosis of Cartilage Cancer

The gold standard for the diagnosis of chondroblastoma is biopsy and microscopic examination of the results. However, before the biopsy, the doctor needs to do:

• Take XQ film. Sometimes this is the only imaging test done before a biopsy if the cancer is too typical.
• MRI, or CT scan. To confirm whether there is really cancer or not, as well as assess their invasive stage.

6. Cartilage cancer treatment

Surgery

Chondroblastoma is usually treated with surgery. Depending on where your cancer is and how big it is, your doctor will recommend different surgical methods. In most cases, surgery will remove both cancer cells as well as some surrounding healthy tissue.

Radiotherapy

Radiation therapy is a treatment that uses beams, such as X-rays and protons. By shooting these rays directly at the tumor, the cancer cells are destroyed.

Doctors don't usually use radiation therapy to treat cartilage cancer. But if your doctor can't surgically remove the entire tumor, they may treat you with radiation.

Valence

It is the delivery of chemicals that kill cancer cells. However, because chemotherapy is cytotoxic, chemotherapy can affect normal cells as well as cause unpleasant unwanted symptoms.

Chemotherapy often has a strong effect on rapidly progressing cancers, and chondrocyte cancers do not have this feature in most cases. Therefore, the role of chemotherapy in this disease is controversial

Although rare, some cases of chondroblastoma grow rapidly. Your doctor will combine both surgery and chemotherapy to destroy this type of cancer.

7. Survival of patients with cartilage cancer

For patients with metastatic cancer to other organs, the 5-year survival rate from the time of diagnosis is 30%. In other words, only one-third of all chondroblastoma patients with metastases are still alive.

In case the patient has no metastases

• Chondroblastoma grade 1: 99% of patients with this type will never have metastases. Therefore, chondrosarcoma at this stage can be considered a focal lesion rather than a cancer. The 10-year survival rate for this group is 83-95%.
• Grade 2 (most chondroblastomas fall into this group): The probability of metastasis of this group is 10-15%, more malignant than grade 1. Therefore, the 10-year survival rate is also reduced correspondingly, only to 64 - 86%.
• Grade 3: This group has a very high metastasis rate, 32 - 70% depending on the study. Survival after 10 years is only about 29-55%. Usually, grade 3 chondroblastoma cannot be treated with surgery alone.

After surgery, in some cases, there may be a recurrence of cartilage cancer in situ. And in most such situations the extent of the cancer is usually the same as that of the original diagnosis. However, 13% of cases of relapse were more severe.

8. Conclusion

Chondrosarcoma, also known as chondroblastoma, is actually mesenchymal cells in the bone marrow. This is a rare type of cancer. It is not uncommon for chondrocyte carcinoma to have symptoms. Patients often discover when a fracture or accidentally detected X-ray.

Treatment of chondrocyte carcinoma is mainly surgical. Radiotherapy and chemotherapy are rarely chosen. The survival rate of patients with chondroblastoma is usually high. Prognosis is significantly reduced if metastases are present.

Doctor Nguyen Doan Trong Nhan