Chondrosarcoma

Overview

Chondrosarcoma is the second most common primary bone cancer. It is a cartilage-forming tumor. Clinicians who treat chondrosarcoma patients must identify the tumor's grade and the possibility of spreading.

Acral lesions, regardless of grade, are unlikely to metastasis, whereas axial, or more proximal, lesions are substantially more likely to spread than tumors located in the distal extremities with comparable histology. Because chondrosarcoma is resistant to both chemotherapy and radiation, the sole therapeutic option is broad local excision.

Because local recurrence is common following intralesional excision, extensive local excision is occasionally used despite severe morbidity, especially in low-grade lesions. Chondrosarcoma is a challenging disease to cure. The surgeon must weigh the danger of severe morbidity against the capacity to reduce the incidence of local recurrence and increase the chances of long-term survival.

Chondrosarcoma definition

Chondrosarcoma is a mesenchymal tumor that mostly consists of cartilage; it is the second most frequent primary malignant bone tumor. Chondrosarcoma is a broad word that refers to a set of heterogeneous tumors with varying morphologic characteristics and clinical behaviors. These lesions range in severity from low-grade tumors with no metastatic potential to high-grade, aggressive cancers with early spread.

When the tumoral matrix is totally cartilage, the word chondrosarcoma should be used to describe a malignant tumor of the cartilage. If the tumor has bone-forming and primitive mesenchymal features as well as cartilaginous differentiation, it should not be classed as a chondrosarcoma since its clinical behavior and treatment responses differ from those of a primary malignant chondrosarcoma.

Tumors containing the aforementioned features (i.e., the presence of bone-forming elements and primitive mesenchymal elements in addition to cartilaginous differentiation) typically behave like chondroblastic osteosarcomas and are more aggressive than ordinary chondrosarcomas.

Epidemiology

Conventional central chondrosarcomas account for about 80-90 percent of all chondrosarcomas and 20-27 % of all primary bone sarcomas. They favor the axial skeleton. The following are the rates of participation:

• Pelvis and ribs, 45%
• Ilium, 20%
• Femur, 15%
• Homarus, 10%
• Others, 10%

The spine and the craniofacial bones are rarely involved.

Dedifferentiated chondrosarcomas may account for up to 10% of all chondrosarcomas. The most prevalent site of involvement is the femur, which accounts for one-third of all dedifferentiated chondrosarcomas. Other sites of involvement include 

• The pelvis (20%), 
• The humerus (16%), 
• The ribs (7%), and
• The scapula (3%). 

Clear cell chondrosarcomas make up less than 5% of all chondrosarcomas. They like the ends of long tubular bones, particularly those involving the epiphysis. These lesions, like chondroblastomas, affect the articular cartilage. The most commonly damaged region (45 percent) is the proximal aspect of the femur, followed by the proximal section of the humorous.

Mesenchymal chondrosarcomas account for less than 2% of all chondrosarcomas. The most prevalent sites of involvement are the maxilla and mandible, followed by the vertebrae, ribs, pelvis, and humerus. The appendicular skeleton is almost never implicated. Juxtacortical chondrosarcomas are uncommon and usually affect the diaphysis or metaphysis of long tubular bones.

Chondrosarcoma types and grades

Different types of chondrosarcoma have been described, as follows:

• Conventional chondrosarcoma, which accounts for nearly 90% of all chondrosarcomas
• Dedifferentiated chondrosarcoma
• Clear cell chondrosarcoma
• Mesenchymal chondrosarcoma
• Juxtacortical chondrosarcoma
• Secondary chondrosarcoma

It might be difficult to distinguish benign cartilage lesions from slow-growing, low-grade chondrosarcomas. A previously benign cartilaginous lesion can develop into secondary chondrosarcoma. Chondrosarcomas are categorized into three histologic classes based on the presence of cellularity, atypia, and pleomorphism:

• Grade I (low grade) – Cytologically similar to enchondroma ; cellularity is higher, with occasional plump nuclei with open chromatin structure
• Grade II (intermediate grade) – Characterized by a definite and increased cellularity; distinct nucleoli are present in most cells, and foci of myxoid change may be seen
• Grade III (high grade) – Characterized by high cellularity, prominent nuclear atypia, and the presence of mitosis

The higher the grade, the greater the likelihood that the tumor will spread and metastasis. Grade I lesions seldom metastasis, but 10-15% of grade II lesions and more than 50% of grade III lesions do.

Who is at risk for chondrosarcoma?

A risk factor is something that raises your chances of contracting a disease. It is possible that the actual etiology of someone's cancer is unknown. However, risk factors can increase a person's chances of developing cancer. Some risk factors may be beyond your ability to control. Others, on the other hand, may be something you can alter. Chondrosarcoma is uncommon in persons under the age of 20. Until roughly the age of 75, the risk increases with age. It affects both men and women equally.

Chondrosarcoma usually begins in normal cartilage cells. It might potentially begin as a noncancerous (benign) bone or cartilage tumor. Some of the benign conditions that may be present when chondrosarcoma occurs are as follows:

• Enchondromas. These are benign bone tumors that begin in cartilage and frequently affect the hands. The reason is unknown.
• Multiple hereditary exostoses (MHE). This is a condition that runs in families (inherited). Many osteochondromas are caused by it. These are cartilage and bone overgrowths at the end of the growth plate of long bones in the arms or legs. Chondrosarcoma can arise from these bone abnormalities.
• Ollier disease. This uncommon condition has no known origin and is not hereditary. It results in clusters of enchondromas, which frequently afflict the hands and feet. It has the potential to induce serious bone abnormalities. Chondrosarcoma affects about one in every three patients with Ollier illness.
• Maffucci syndrome. This extremely rare condition is not hereditary. It is the cause of numerous enchondromas, which mainly afflict the hands and feet, as well as benign tumors formed up of blood vessels (angiomas). It raises the chance of chondrosarcoma and other cancers.
• Li-Fraumeni syndrome. This is an inherited disease that's linked to a higher risk of many types of cancer, including chondrosarcoma.

Consult your doctor about your risk factors for chondrosarcoma and what you can do about them. 

Pathophysiology

Multiple chromosomal abnormalities have been reported in chondrosarcomas. The examination of chromosomal structural abnormalities and genetic instability in well-differentiated chondrosarcomas revealed chromosomal structural abnormalities and genetic instability. Furthermore, MYC and AP-1 transcription factor amplification is significant in the etiology of chondrosarcoma.

Clinical presentation

Deep, dull, achy ache is a common sign of chondrosarcoma. Nighttime pain is another symptom. Although pain can help distinguish between malignant and benign cartilaginous lesions, it can be untrustworthy when the small bones of the hands and feet are involved.

If the lesion is near a neurovascular bundle, as with pelvic lesions, the patient may have nerve dysfunction of the lumbosacral plexus, sciatic, or femoral nerves. If a chondrosarcoma is located near a joint, it may restrict the joint's range of motion and lead it to malfunction. These symptoms are common in juxtacortical chondrosarcomas, although they can also be seen in pathologic fractures. More than half of all patients with dedifferentiated chondrosarcomas have a pathologic fracture.

the average duration from pain to diagnosis for grade I, grade II, and grade III chondrosarcomas is 19.4 months and 15.5 months, respectively. Clear cell chondrosarcomas and mesenchymal chondrosarcomas may induce symptoms for more than a year due to their low-grade nature. Mesenchymal chondrosarcomas can have soft-tissue masses.

Diagnosis

Plain radiography:

For first examination, plain radiography is employed. Plain x-rays can identify the cartilaginous type and severity of the lesion. Plain x-rays may reveal the following:

• Lytic lesions in 50% of the cases
• Intralesional calcifications: in about 70% of the cases (popcorn calcification or rings and arcs calcification)
• Endosteal scalloping   
• Permeative appearance or moth-eaten appearance in high-grade chondrosarcomas
• Cortical remodeling, thickening, and periosteal reaction  

Computed tomography scan:

Computed tomography scan can reveal the following findings:

• Matrix calcification in 94% of the cases
• Endosteal scalloping
• A cortical breach in about 90% of long bone chondrosarcoma
• Heterogenous contrast enhancement

Secondary malignant degeneration should be considered when the following symptoms are shown on consecutive follow-up radiographs of benign cartilage tumors:

• Growth of the lesion
• Decreased calcification and increased lysis
• Endosteal erosion
• Permeative lesions with destruction of the cortex
• Soft-tissue mass
• Growth in a previously stable exostosis or enchondroma in an adult
• Expansion of the cartilaginous cap in exostosis

Magnetic resonance imaging:

MRI is the preferred method of diagnosing the degree of a chondrosarcoma; it also aids in determining the level of soft-tissue involvement. Its capacity to assess the precise amount of the tumor as well as the extent to which distinct soft-tissue compartments are implicated makes it a significant tool for preoperative planning.

MRI is also useful for verifying or detecting recurrence at a surgically treated location. Dynamic contrast-enhanced MRI has been shown to be beneficial in differentiating benign from malignant lesions when used in conjunction with conventional MRI.

Tissue biopsy:

It is difficult to perform a fully representative biopsy of a chondrosarcoma since the disease is made up of sections with varying histologic grading. It is crucial to identify the tumor's most aggressive component. Consider the following before doing a biopsy:

Biopsies can be done using either an open or closed approach. Fine-needle aspiration (FNA) cytology or core biopsy are used in closed biopsy. Core biopsy using a Tru-Cut biopsy or a core needle biopsy produces findings comparable to open biopsy. Image-guided needle biopsy may be more accurate than pelvic chondrosarcoma grading.

It is critical to consult with the radiologist and the histopathologist in order to collect the suitable tissue for biopsy. However, in the case of cartilaginous tumors, histopathologic analysis of the biopsy specimen alone does not allow appropriate tumor categorization.

Chondrosarcomas are typically gelatinous in nature. As a result, there is a considerable danger of bone-tumor cells infiltrating the biopsy tract. Furthermore, due to the avascular nature of the cartilaginous tumor matrix, malignant cartilage cells can survive when spilled into a lesion. For these reasons, a chondrosarcoma biopsy should be performed as thoroughly as feasible. When performing a definitive surgery, the whole tract should be removed.

Findings suggestive of secondary malignant degeneration

Secondary malignant degeneration should be considered when the following symptoms are shown on consecutive follow-up radiographs of benign cartilage tumors:

• Growth of the lesion
• Decreased calcification and increased lysis
• Endosteal erosion
• Permeative lesions with destruction of the cortex
• Soft-tissue mass
• Growth in a previously stable exostosis or enchondroma in an adult
• Expansion of the cartilaginous cap in exostosis

Management

Surgery:

The therapeutic options for chondrosarcoma are determined by its location and histologic grade. Chondrosarcoma is treated mostly by surgical excision. Intralesional curettage, burring, and surgical adjuvant applications such as hydrogen peroxide can be used to treat low-grade central chondrosarcoma.

Tumors involving the intraarticular or soft tissues, as well as bigger tumors, axial or pelvic tumors, must be treated with a broad excision. The surgical strategy of choice for intermediate or high-grade chondrosarcoma is extensive en bloc excision.

Chemotherapy:

Chemotherapy is often ineffective in traditional chondrosarcoma. It may, however, have a role in dedifferentiated chondrosarcomas with a high-grade spindle cell component.

Radiation therapy:

Radiation treatment is recommended after incomplete resection of high-risk chondrosarcomas to reduce the high local failure rates. Locally recurring cancers of moderate to high grade, as well as tumors in places where surgical resection is difficult or restricted, are among the indications. In the case of unresectable malignancies, definitive radiation may be needed.

Prognosis

The single most important predictor of local recurrence and metastasis is histological grade. Low-grade chondrosarcomas have a favorable prognosis since they develop slowly and seldom spread. Grade I chondrosarcomas had an 83 percent 5-year survival rate. High-grade chondrosarcoma and dedifferentiated chondrosarcoma, on the other hand, have a poor prognosis due to the tumor's fast development and proclivity for early spread. The 5-year survival rate for grade II and III chondrosarcomas is 53%.

Recurrence and distant metastases are possibilities. Primary chondrosarcoma has a greater metastasis rate than secondary chondrosarcoma, and individuals with local recurrence had a higher incidence of distant metastasis than those without local recurrence. Chondrosarcoma of the bone has a fairly excellent prognosis in children and adolescents and is less aggressive than in older individuals.

Staging

The Enneking staging system for musculoskeletal sarcomas is applicable to chondrosarcomas, as follows :

• Stage I (low-grade tumor) - I-A, intracompartmental; I-B, extracompartmental
• Stage II (high-grade tumor) - II-A, intracompartmental; II-B, extracompartmental
• Stage III (distant metastasis)

Conclusion 

Chondrosarcomas are malignant cartilaginous neoplasms with a wide range of morphological and clinical characteristics. They account for approximately 20% of all initial malignant bone tumors. They often develop in the pelvic or long bones. Primary chondrosarcoma develops in preexisting normal bone, as opposed to secondary tumors, which develop in a preexisting enchondroma or osteochondroma.

Conventional chondrosarcoma, which accounts for 85–90% of all chondrosarcomas, is further split into central, periosteal, and peripheral subgroups. Clear cell chondrosarcoma, mesenchymal chondrosarcoma, and dedifferentiated chondrosarcoma are examples of non-conventional chondrosarcomas.

The radiographic characteristics of chondrosarcoma are frequently quite distinctive, and a conclusive diagnosis may generally be determined based only on imaging evaluation. Chondrosarcoma is best addressed by a multidisciplinary team that includes orthopedists, radiologists, surgical oncologists, oncologists, pathologists, and specialized care nurses. The correlation of the lesion's gross, radiological, and microscopic characteristics is critical for establishing the conclusive diagnosis of chondrosarcoma.

Patients require long-term follow-up after surgery due to the likelihood of tumor recurrence and distant metastases. Patients with low-grade illness have a great prognosis. Pharmacists examine drugs, look for drug-drug interactions, and educate patients.

Specialty care nurses in anesthesia, operating rooms, orthopedics, and oncology monitor patients, educate patients and their families, and provide team updates on the patient's health. As a result, the team will be able to enhance outcomes for this ailment.