Musculoskeletal tumors

Overview

Tumors can form in bone or soft tissue, which connects and supports the musculoskeletal system. Sarcomas are cancerous tumors that are malignant in nature. The examination of musculoskeletal tumors involves close coordination between the orthopedic oncologist, radiologist, and pathologist. Following the appropriate diagnostic techniques and staging studies can result in a favorable outcome in a high percentage of patients. 

 

What are Musculoskeletal tumors?

Musculoskeletal cancer refers to any cancer that arises in the bones or muscles of the body. Rhabdomyosarcoma, osteosarcoma, and Ewing's sarcoma are three types of malignant musculoskeletal tumors that often affect adolescents, teenagers, and young adults (30 years old). They account for around 10% of newly diagnosed cancers in children, adolescents, and young adults (about 1000 cases annually in the United States). Although common in young people, these tumors are uncommon in the elderly. 

 

What is the prevalence of Musculoskeletal tumors?

Bone and cartilage sarcomas account for less than 0.5 % of all human malignancies. They are far more common in children than in adults. Soft tissue sarcomas are three to four times more prevalent, with the vast majority of cases occurring after the fifth decade of life. Benign bone and soft tissue tumors are 100 times more common than malignant tumors, with an overall incidence of 300 per 100,000 population.

The yearly incidence of breast, prostate, and lung cancers in the United States of America is around 180,000 to 200,000, reflecting the low frequency of primary bone and soft tissue tumors. As cancer patients' survival rates improve, so will the number of those who arrive with bone metastases. 

 

Musculoskeletal Risk factors

Musculoskeletal malignancies are tumors that damage your body's bone and muscle tissues. Cancers of this sort include:

• Bone sarcoma: These cancers, which begin in the bone, are known as osteosarcoma, Ewing sarcoma, or chondrosarcoma.
• Rhabdomyosarcoma: This cancer originates in the muscles and is most frequent in youngsters, with many instances beginning before birth.
• Soft tissue sarcoma: Soft tissues, such as fat, nerves, muscle, deep skin tissue, and blood vessels, are the most usually affected by this type of cancer.
• Bone metastasis: When cancer spreads from another part of your body to your skeletal or muscular systems, this occurs.

Musculoskeletal cancer poses a variety of risks. Bone cancer is more frequent in children and the elderly. Men, African Americans, Caucasians, and anyone who have been exposed to radiation are also at a higher risk. Ewing sarcoma is more common in younger people, men, and Caucasians.

Soft tissue sarcoma is more common in people with a family history of the disease or who have a weakened immune system. While there is no one-size-fits-all method for avoiding musculoskeletal malignancies, a healthy lifestyle and periodic screenings can help detect cancer early. 

 

Musculoskeletal tumors symptoms

Malignant bone tumors are unpleasant because the weakening of the bone architecture results in microfractures, which cause pain. The appearance of a pathological fracture in a child without prior symptoms typically indicates the existence of a benign lesion (i.e., a bone cyst) that has gradually undermined the cortex, culminating in a fatigue fracture.

In the elderly, the similar clinical picture suggests lytic metastasis invasion or, in certain circumstances, metabolic bone disease such as hyperparathyroidism. Malignant soft tissue tumors often present as a painless growing mass with occasional discomfort caused by pressure on adjacent tissues (e.g., nerves) or erosion of a neighboring bone.

Patients with spinal tumors usually complain of axial pain, with some additionally reporting radicular pain (if the tumor extends to and compresses the nerve roots). Cauda equina syndrome, which is more prevalent with metastatic sickness and rapidly growing initial tumors, affects fewer people. Although the majority of patients experience axial or radicular pain, almost one-third also suffer motor dysfunction. Bowel/bladder sphincter dysfunction affects just a small fraction of the population.

When evaluating a primary bone tumor, it is critical to consider the patient's age. A bone lesion with a soft tissue mass in a kid under the age of five is more likely to be osteomyelitis or Langerhans cell histiocytosis than a primary malignant bone tumor. Less common are Ewing's sarcoma, neuroblastoma metastases, and leukemia involvement. Primary osteosarcoma is most frequent in the second decade of life, when bone growth is at its maximum.

Myeloma and metastases are significantly more likely in people over 50, albeit chondrosarcoma and secondary osteosarcoma (due to osteonecrosis, radiation, etc.) are the most common bone malignancies. The majority of soft tissue sarcomas attack the elderly, with the exception of rhabdomyosarcoma and synovial sarcoma, which affect youngsters and teens.

The history includes important details such as night discomfort/rest aching and a rise in the size of a mass. Night discomfort is less prevalent in a stress reaction/fracture. Similarly, recent or subacute trauma increased the likelihood of a hematoma or myositis ossificans. In the past, other causes of bone lesions, such as metabolic disorders and steroid-induced avascular necrosis, should have been examined. 

 

Diagnosis of Musculoskeletal tumors

Unlike many other cancers, most bone and muscle tumors produce no symptoms. They can be diagnosed by physical exams, imaging, biopsies, and blood testing. Rhabdomyosarcoma is an exception, with symptoms occurring after the disease has advanced. This is why regular screenings are so important. If your doctor identifies muscle or skeletal cancer, they will evaluate your overall health in order to stage the disease. This is the first step in developing a treatment strategy.

Although magnetic resonance imaging (MRI) has traditionally been used to help detect the extent of sickness prior to therapy in the assessment of musculoskeletal malignancies, its function is evolving as new methods emerge. Traditional pulse sequences are still widely used and useful, but the introduction of chemical shift imaging, diffusion-weighted imaging, perfusion imaging, and MR spectroscopy has provided additional quantitative metrics that may help expand the role of MR imaging to include detection, characterization, and reliable assessment of treatment response. 

 

Osteosarcoma

The most common malignant bone tumor, osteosarcoma, is a fatal kind of musculoskeletal cancer that frequently ends in lung metastasis.

Osteosarcoma is thought to emerge from primitive mesenchymal bone-forming cells, and its pathologic feature is the production of malignant osteoid. Other cell populations may be present since pluripotent mesenchymal cells can give birth to these cells, but any region of malignant bone in the lesion validates the diagnosis of osteosarcoma.

The bulk of osteosarcomas start as solitary lesions in the fastest growing areas of children's long bones. The most typically afflicted bones are the distal femur, proximal tibia, and proximal humerus, however, almost any bone can be impacted.

Not all osteosarcomas grow spontaneously. Many spots may become evident within 6 months (synchronous osteosarcoma), or multiple sites may be discovered over a longer period of time (chronic osteosarcoma) (metachronous osteosarcoma). This kind of multifocal osteosarcoma is exceedingly rare, yet it generally affects youngsters under the age of 10.

Osteosarcoma is a kind of bone tumor that can develop in any bone, but most commonly at the extremities of long bones near metaphyseal growth plates. The following are the most prevalent areas:

• Femur (42%, 75% of which are in the distal femur)
• Tibia (19%, 80% of which are in the proximal tibia)
• Humerus (10%, 90% of which are in the proximal humerus)
• Skull and jaw (8%)
• Pelvis (8%)

 

Osteosarcoma symptoms

Pain is the most prevalent presenting sign, especially during exercise. Except in the case of telangiectatic osteosarcoma, pathologic fractures are uncommon. A limp can be caused by pain in the extremities. Swelling may or may not have occurred in the past. Systemic symptoms are uncommon. Only in rare cases can tumor progression to the lungs cause respiratory problems. Other symptoms are unusual since metastases to other places are quite infrequent.

Physical examination findings are often restricted to the main tumor site and may include the following:

• Mass
• Decreased range of motion (ROM)
• Lymphadenopathy
• Respiratory findings

 

Osteosarcoma Causes

It is uncertain what causes osteosarcoma. A variety of risk factors, however, have been discovered.

Rapid bone growth appears to predispose people to osteosarcoma, as evidenced by the increased incidence during the adolescent growth spurt, the high incidence in large-breed dogs, and the typical location of osteosarcoma in the metaphyseal area adjacent to the growth plate (physis) of long bones.

A genetic predisposition is involved. Risk factors include bone dysplasias such as Paget disease, fibrous abnormalities, enchondromatosis, hereditary multiple exostoses, and retinoblastoma (germline type). Radiation exposure is the only recognized environmental risk factor. 

 

Osteosarcoma Prognosis

The current understanding of osteosarcoma outcome and prognosis is driven by serum indicators, clinical staging, and histologic response to chemotherapy drugs.

The overall relative 5-year survival rates were as follows :

• Age < 25 years - 61.6% (females, 65.8%; males, 58.4%)
• Age 25-59 years - 58.7% (females, 64%; males, 54.6%)
• Age 60-85+ years - 24.2% (females, 27.0%; males, 19.9%), with a drastic drop with advancing age (from ~50% for patients in their 50s to 17% for those in their middle-to-late 60s and to 10.8% for those aged 80 years or older) 

Patients with increased ALP levels at the time of diagnosis are more likely to have lung metastases. Patients with increased LDH are less likely to perform well than those with normal LDH in the absence of metastases.

Osteosarcoma Treatment 

Prior to the introduction of chemotherapy in the 1970s, osteosarcoma was mostly treated with surgical excision (usually amputation). Despite such strong local control, more than 80% of patients acquired recurrent illness, which often manifested as lung metastases. The high rate of recurrence suggests that the majority of individuals had a micrometastatic illness at the time of diagnosis. As a result, the use of adjuvant (postoperative) systemic chemotherapy is crucial for the treatment of osteosarcoma patients.

Most of the time, limb-sparing (limb-preserving) treatments may be utilized to treat this condition and so retain function. In rare cases, amputation may be necessary. Chemotherapy is also necessary to treat micrometastatic illness, which is present but generally undetectable at the time of diagnosis in the majority of patients (80%)

The orthopedic surgeon is crucial in the treatment of osteosarcoma patients. Patients suspected of having osteosarcoma are frequently sent to an orthopedic surgeon for a diagnosis. Furthermore, because osteosarcomas do not respond well to treatment, surgery is the sole choice for final tumor excision.

Following surgical excision, an oncologic kind of complete joint prosthesis or sophisticated bone repair may be necessary. As a result, strong collaboration between the orthopedic surgeon and the medical oncologist is essential at the time of diagnosis, as well as throughout and after treatment.

Biopsy and extensive resection are the two most common treatments done by orthopedic surgeons on patients with osteosarcoma. Neither of these procedures should be performed until full tumor staging has been accomplished prior to surgery. This type of staging would normally comprise (but is not limited to) the following:

• Plain radiography of the involved bone, including the joint above and the joint below the affected region
• Total-body bone scanning
• Magnetic resonance imaging (MRI) of the primary tumor area to include the entire bone of origin
• Computed tomography (CT) of the lungs

Because osteosarcoma is a lethal form of cancer, there are no absolute contraindications to treatment. Situations in which the patient is so fragile that the hazards of general anesthesia outweigh any potential advantages of surgery would be considered relative contraindications. Another related contraindication would be if the patient suffers from significant, overwhelming metastatic illness and the advantages of comfort or hospice care outweigh the possible benefits of surgical intervention.

 

Fibrosarcoma

Fibrosarcoma is a mesenchymal cell tumor that can manifest as a soft-tissue mass or a primary or secondary bone tumor. Fibrosarcoma was once diagnosed much more frequently than it is now; in current practice, it can be distinguished histologically from similar lesions such as desmoid tumors, undifferentiated pleomorphic sarcoma, malignant fibrous histiocytoma, malignant schwannoma, and high-grade osteosarcoma more reliably.

The mainstay of treatment for fibrosarcoma, as with all soft-tissue and bone sarcomas, has been complete excision with an adequate margin; this procedure became common following the publication and widespread acceptance of Enneking's surgical principles of musculoskeletal oncology in the early 1980s. This procedure often involves resecting a cuff of normal tissue beside the tumor.

The long-term survival and eventual functional success of fibrosarcoma therapy are determined by a number of interconnected elements. These include the tumor's size and location, histologic grade, and the existence of metastatic disease (eg, pulmonary metastases). These characteristics are included during the meticulous examination (stage) of the tumor, and they impact the efficacy of treatment in achieving excellent local control and preventing later disease spread.

Continued developments in sarcoma molecular biology may help to better understand the extremely different clinical behavior of the numerous kinds of fibrosarcoma and, ultimately, give improved therapeutic options.

 

Fibrosarcoma Symptoms 

After a long period without symptoms, bone sarcomas frequently manifest with pain and swelling. As the first appearance, they may become big enough to jeopardize the structural integrity of the bone and induce pathologic fracture.

Lesions that cover more than 50% of the bone cortex, are greater than 2 cm or involve the femoral medial calcar are linked with the highest risk of fracture. A history of bone infarction, irradiation, or other risk factors should alert the doctor to the probability of subsequent fibrosarcoma.

Soft-tissue sarcomas typically manifest as painless masses. However, the period to manifestation is frequently shorter than in bone lesions. Because these lesions typically start deep inside the muscle fascia, they might grow to be exceedingly massive tumors before being detected.

The majority of lesions occur at the knee, proximal femur, and hip area, or proximal arm. Nonspecific findings include a stable, hard mass and a localized region of discomfort. Late indications of neurologic or vascular abnormalities suggest significant disease involvement.

 

Fibrosarcoma Treatment & Management 

To achieve local control, surgical excision with a cuff of normal tissue (broad margins) and subsequent defect repair are required. Surgical therapy for fibrosarcoma (including biopsy) should not begin until comprehensive patient care is provided. Biopsy and interpretation of biopsy findings, access to oncologists and radiation oncologists, and ultimate resection are all part of comprehensive treatment.

Fibrosarcomas should be removed by skilled orthopedic oncologists who can give a cutting-edge treatment plan; this would entail a team of well-educated doctors with extensive expertise treating these tumors.

• Medical Therapy

Adjunctive therapy, such as radiation therapy and chemotherapy, can enhance local control and reduce the likelihood of clinically detectable metastatic illness. The utility of chemotherapy is debatable, yet it is commonly utilized in bone lesions. Radiation treatment, with or without chemotherapy, is used in combination with surgery for soft-tissue fibrosarcomas.

• Surgical Therapy

In general, fibrosarcoma treatment entails a mix of sufficient local tumor management and prevention or treatment of distant illness. Many factors come into play and influence the final diagnosis. To achieve local control, surgical excision with a cuff of normal tissue (broad margins) and subsequent defect repair are required.

 

Conclusion 

Musculoskeletal tumors can develop in both bone and soft tissues. The vast majority of them are benign; nonetheless, malignant neoplasms do arise on rare cases.