Chest wall tumor

Overview

The structures surrounding and protecting the lungs, contained by the spine and divided from the abdomen by the diaphragm, are referred to as the chest wall. Cartilage, bone, muscle, fascia, vasculature, lymphatic vessels, fat, and skin are among the tissues that make up these structures. Primary and secondary chest wall tumors are the two types of tumors.

Muscle, fat, blood vessel, nerve sheath, cartilage, or bone of the chest wall can all cause primary chest wall tumors. Secondary chest wall tumors can result from direct invasion of breast or lung carcinomas, as well as metastases from a distant origin. On the surface, chest wall tumors are difficult to detect; nevertheless, a thorough history and physical examination can lead to proper imaging and management.

It's critical to understand the various imaging modalities available and the information that may be gleaned from obtaining the appropriate modality. A biopsy is the gold standard for determining a definitive diagnosis, and surgical options can be discussed with the patient, along with the necessary risks and benefits. Because these tumors affect a wide range of specializations and providers, it's critical to adopt an interprofessional approach to patient treatment.

Origin of chest wall tumors 

Tumors of the chest wall can form in the bones, soft tissues, and cartilage of the chest cavity, which houses the heart, lungs, and other organs. These tumors are frequently malignant and have invaded or metastasized from surrounding thoracic malignancies in more than half of cases. Secondary chest wall tumors can result from direct invasion of breast or lung carcinomas, as well as metastases from a distant origin.

The majority of chest wall tumors discovered in children are primary, whereas the majority of those found in adults are secondary. All of these tumors present as a bump on the surface of the chest wall or as a growth that invades the bone or muscle.

Epidemiology

Males and females have different rates of chest wall tumors, according to research. Younger people tend to have smaller, more benign tumors, whereas older patients tend to have larger, more aggressive tumors.

The prevalence of primary chest wall tumors is less than 2% of the population. Chest wall neoplasms can be primary or metastatic, with a malignancy incidence of around 50%, and can be symptomatic or asymptomatic, with about 20% discovered by chance on a chest radiograph. Primary chest wall tumors account for 5% of all thoracic cancers.

Chondrosarcomas, osteosarcomas, rhabdomyosarcomas, plasmacytomas, malignant fibrous histiocytomas, and Ewing sarcomas are all sarcomas of the chest wall that develop in the cartilage, soft tissues, and bones of the chest cavity. Chondrosarcomas are the most common primary malignant chest wall tumors.

Malignant tumors make up between half to eighty percent of chest wall tumors, with 55 percent coming from bone or cartilage and 45 percent from soft tissue. The overall five-year survival rate after excision of primary chest wall neoplasms is around 60%. Recurrence can occur in up to half of patients, resulting in a five-year survival rate of only 17%.

Etiology 

Chest wall tumors can be caused by benign or malignant cellular expansion and proliferation, infectious or inflammatory mechanisms.

Tumors of the bone, muscle, fat, blood vessels, nerve sheaths, myositis ossificans, elastofibroma dorsi, and extra-abdominal desmoid tumors are all examples of primary chest wall tumors. Metastases from other bodily organs cause secondary chest wall tumors.

The exact cause of chest wall tumors is currently unknown in the literature; however, it is hypothesized that genetics, food, and lifestyle choices may all play a role in the formation of these tumors.

Extra-abdominal desmoid tumors are a type of aggressive fibromatosis that can arise from a previous thoracotomy.

The Mechanics of Chest Wall Tumors

Primary and secondary chest wall tumors, whether malignant or benign, are divided into two categories (metastatic). Primary tumors start in the chest wall's bone or muscle. Secondary tumors begin elsewhere in the body and spread to the chest wall (metastasize). Almost all secondary tumors are cancerous. The majority of primary chest wall tumors identified in children are primary, while the majority of secondary tumors seen in adults are secondary. These tumors are typically a bump on the chest wall surface or a growth that has invaded the bone or muscle.

It's possible that the proclivity for benign tumors runs in families. Multiple or recurring benign tumors can lead to the development of a malignant tumor in certain persons. The prognosis for malignant tumors of the chest varies depending on the stage at which the tumor is discovered and treated.

Types of Chest Wall tumors

The following types of sarcomas could grow in the chest wall:

• Chondrosarcoma: The most prevalent kind of primary chest wall bone cancer, it develops in cartilage. It usually manifests as a painful, slowly growing lump.
• Osteosarcoma: Typically forms in bone at a period of rapid growth, such as adolescence. It usually manifests as a painful, rapidly growing lump.
• Ewing’s sarcoma: It is more common in children and young adults, and it forms in the bone. It usually manifests as a painful mass accompanied by fever and exhaustion.
• Plasmacytoma: Isolated kind of multiple myeloma that develops from plasma cells. It's possible that you'll feel discomfort but not see a mass. This is one of the few tumors on the chest wall that we only treat surgically on a very rare basis.
• Malignant fibrous histiocytoma: This is the most prevalent soft tissue sarcoma, and it mostly affects adults. These normally appear as a painless, slowly expanding lump.
• Rhabdomyosarcoma: It is more common in children and young adults, and it develops in striated muscle. The most common symptom is a quickly developing, painless lump.

Chest wall tumor symptoms

When examining a patient with a chest wall mass, a thorough history and physical examination are required. Pain, discomfort, swelling, decreased movement, a lump, or muscular atrophy are all common complaints. Physical examination may indicate visible swelling, and careful probing of the chest wall may reveal underlying asymmetry and characterize the texture of the tumor. Breath sounds may be reduced as well. All of these symptoms are caused by the tumor's bulk effect and are not indicative of the tumor's underlying pathology.

Symptoms of benign chest wall tumors may include one or more of the following:

• A localized mass
• Swelling
• Chest Pain
• Muscle atrophy (breakdown)

Symptoms of malignant chest wall tumors may include one or more of the following:

• A localized mass
• Swelling
• Chest Pain
• Impaired movement or chest expansion

Diagnosis

A history of trauma to the chest wall in a patient with chest wall pain or mass may indicate that the lesion is not malignant; nonetheless, some patients may attribute a painful mass to a recent injury when it is in fact cancerous. The etiology of the chest wall mass might be determined with the help of a history of another cancer. The pace of expansion over time can also be determined if the lesion is palpable. A physical examination may or may not identify a mass, and it should include a lymphadenopathy check.

Chest x-rays (CXR) can describe the mass and show pulmonary metastases, which are often the initial imaging tool employed in the diagnosis of chest wall cancers. Furthermore, some cancers are discovered by chance on CXR. CXR can still provide useful information on tumors, even though it is insufficient as the sole imaging modality in today's era of improved imaging tools. It is possible to determine the size, position, calcification, ossification, and bone involvement. When it comes to detecting calcification and cortical damage, CT is more sensitive than CXR.

It gives you a lot of information about the tumor's size, location, bone involvement, and local infiltration. If lung metastases are present, they can also be seen. Intravenous contrast can also be utilized to determine tumor vascularity. CT is also important for operational planning and evaluating chemotherapy or radiation response. Many chest wall cancers are now imaged using magnetic resonance imaging (MRI).

It gives specific details about soft-tissue involvement and extend to the spine or thoracic inlet (brachial plexus, subclavian artery, subclavian vein). To check for metastases and rule out another primary tumor, a radionucleotide bone scan is advised. Another imaging technique that can be utilized to assess chest wall cancers and their metastases, particularly in terms of staging, is PET using 18F-fluorodeoxyglucose.

Although there is minimal data on the use of PET or PET combined with CT (PET/CT) to characterize and stage other cancers, the application of PET or PET combined with CT (PET/CT) to characterize and stage other malignancies appears promising. PET has been demonstrated to be more sensitive than traditional imaging techniques, such as CT and MRI, in detecting primary tumors (100 %), lymph node involvement (95 %), and bone manifestations (89 %) in sarcomas. 10 PET/CT demonstrated enhanced ability to detect metastases in a research comparing it to traditional imaging modalities in staging rhabdomyosarcoma (89 percent versus 63 %).

PET has been proven to better describe tumor extent for a variety of chest wall tumors when compared to CT. PET has been demonstrated to be highly accurate in detecting local recurrence (88 percent) and properly recognizing benign lesions when restaging sarcomas (92 % ). PET has also been demonstrated to be more accurate than CT in terms of not only initial staging, but also evaluating sarcoma treatment response.

PET and PET/CT clearly show significant promise in the imaging of chest wall malignancies, but more research is needed, particularly prospective studies and studies specific to the chest wall. To properly treat chest wall cancers, a precise tissue diagnosis is required. The ideal procedure for diagnosing tiny tumors is excisional biopsy, which requires margins of at least 1 to 2 cm.

Excessive dissection and manipulation of the tissues should be avoided during the surgery, since this can affect the subsequent wide excision. For bigger tumors (5 cm), incisional biopsy can be conducted; the orientation of the incision should take into account the incision that would be needed for definitive excision. When metastatic epithelial tumors are suspected, fine-needle aspiration is beneficial; however, fine-needle aspiration is less accurate for primary chest wall cancers, especially when determining grade and differentiation.

Chest wall tumor removal 

Chest wall tumors can be difficult to treat both clinically and surgically. The mainstay of therapy for benign tumors is surgical resection. The treatment of malignant tumors necessitates a more collaborative approach in order to maximize functional outcomes. The presence of wide tumor excision with negative margins is a strong predictor of local recurrence rates. To avoid a negative impact on respiratory function, chest wall stabilization is also required following resection.

Most chest wall defects can be covered using a variety of muscle flaps, including pectoralis flap, latissimus dorsi flap, and rectus abdominis flap, depending on the location and extent of the defect. Because of inadequate resection, failed reconstruction, and, in some circumstances, inaccurate diagnosis, these procedures have significant rates of perioperative morbidity and mortality.

For original tumors and a limited group of secondary tumors of the chest wall, surgery with resection has proven to be the best treatment, and it may even be curative. Combining surgery with radiation therapy and/or chemotherapy may be necessary, however this is dependent on the tumor's histology.

Differential Diagnosis

The list of possible diagnoses for chest wall tumors is endless. The differential includes benign and malignant lesions that may be a local extension of another disease. Local symptoms of inflammatory or infectious etiologies can also be included. The following factors might help narrow down the differential diagnosis of chest wall tumors: overall prevalence and clinical symptoms, mineralization patterns, position on the chest wall, and intrinsic magnetic resonance imaging features that match histopathologic results.

Most Common Benign Tumors:

• Osteochondromas
• Chondromas
• Fibrous dysplasia
• Desmoid tumors

Most Common Malignant Tumors:

• Soft tissue sarcomas
• Chondrosarcomas
• Ewing sarcoma

Prognosis

The pathologic etiology of the tumor determines the prognosis completely. If the tumor's mass effect causes discomfort, neurovascular entrapment, or cosmetic issues, surgical intervention is required. Patients who have undergone surgical resection have a fair prognosis. Patients with a malignant disease, on the other hand, have a bleak outlook. Although a multidisciplinary approach is required, metastatic illness has a dismal prognosis.

Complications

If individuals refuse surgery or are not surgical candidates, serious problems are possible. Increased discomfort, edema, neurovascular entrapment leading to ischemia and paresthesias, and cosmetic distortion of body habitus may be experienced by these patients. Patients who choose surgery are at risk for surgical consequences such as nerve injury, vascular ligation, and respiratory compromise, among others.

Patients require pain treatment and respiratory supportive care following surgery. The depth and breadth of invasion, as well as the underlying natural etiology of the tumor, influence morbidity and mortality. Cell type has an impact on oncologic outcomes and overall survival; with more aggressive histology, recurrence rates are higher.

Chondroma

Chondromas are benign cartilaginous tumors that make up 15% to 20% of all benign chest wall lesions. They usually appear near the anterior costochondral junction in the second to third decades of life. They take a long time to grow and are usually painless. The term enchondroma refers to a chondroma that arises from the medulla of the bone.

They present on CXR as a lytic region with a sclerotic edge, making them difficult to differentiate from a low-grade chondrosarcoma. Chondromas can be difficult to distinguish from low-grade chondrosarcomas histologically, hence all condromas should be treated as cancerous unless proven differently. Excision of a large portion of the body is required for treatment.

Osteochondroma 

Osteochondroma is a bone and cartilage tumor that is benign. It accounts for about half of all benign rib tumors and is the most prevalent benign bone tumor. Young men are the most typically impacted,4 and men are three times more likely than women to be harmed. The mass is formed by the rib cortex, which is normally located on the metaphysis.

When the tumor develops outward, it appears as a painless lump, but when it grows inward, it is usually asymptomatic. A pedunculated or sessile tumor with a cartilage cap is seen on CXR. Familial osteochondromatosis can manifest as several lesions. Fractures, bone abnormalities, and nerve compression are all possible complications of osteochondroma.

If there is discomfort, erosion of the bone, abnormal calcifications, or thickening of the cartilage cap, malignant transformation is possible and should be considered. All patients who have reached puberty require resection as part of their treatment. If the tumor is growing in size or causing symptoms before puberty, it should be removed. 

Aneurysmal bone cyst 

Aneurysmal bone cysts are made up of a network of blood-filled cysts bordered by fibroblasts and multinucleated large osteoclast cells. The majority of cases occur in patients under the age of 30 and, when they occur in the chest wall, they usually occur in the posterior components of the spine. Rapid growth, bone disintegration, and expansion into surrounding tissue are all possibilities.

An expansile lesion with a well-defined inner edge is shown on CXR. A lobulated or septated tumor with a thin, well-defined rim of low-signal intensity is frequently seen on MRI.  Excision of a large area of the body is required for treatment. Long-term survival statistics are scarce.

Langerhans cell histiocytosis

Eosinphilic granuloma, also known as Langerhans cell histiocytosis, accounts for 10% to 20% of benign rib tumors. It's a widespread inflammatory infiltrative process that can affect a variety of organs, including chest wall bones. Men are five times more likely than women to be affected. Patients usually complain of chest pain, as well as fevers and malaise.

Langerhans cell histiocytosis can be seen on CXR as an expansile bone lesion with uneven cortical destruction and new subperiosteal bone growth.  It's easy to mix it up with cancer or osteomyelitis. For a single lesion, excisional biopsy is used, and for many lesions, radiation therapy is used.

Desmoid 

Desmoid tumors are fibrous benign tumors that arise from musculoaponeurotic tissues all over the body. They often extend along tissue planes and encase the brachial plexus as well as arteries in the arm and neck.

Desmoids tumors can also spread into the pleural space, dislodging mediastinal structures. Patients usually complain of pain, but if the tumor has spread to the thoracic inlet, they may also experience paresthesias, hyperesthesias, and motor paralysis.

The majority of cases occur between the ages of puberty and 40. They emerge as monotonous patterns of elongated spindle-shaped cells penetrating the surrounding tissue on histological examination. Although most pathologists regard them as benign, others consider them to be a low-grade fibrosarcoma due to reports of malignant degeneration. To visualize tumor penetration into adjacent tissues, an MRI is indicated.

The most common treatment is a broad resection. Enucleation followed by radiation therapy is used if the tumor engulfs the structures of the thoracic outlet. In the case of negative margins, the benefit of postoperative radiation therapy has yet to be determined. Because desmoids have a tendency to return locally, with recurrence rates ranging from 25% to 75%, achieving appropriate surgical margins is critical.

MALIGNANT TUMORS

Chondrosarcoma 

The most frequent malignant bone tumor of the chest wall is chondrosarcoma. It usually appears in the third to fourth decades of life and is uncommon in people under the age of 20. It's more common in men than in women. Chondrosarcomas can develop as a result of malignant degeneration of benign chondromas or osteochondromas, however the majority of cases begin from normal tissue. They may also be linked to a traumatic event. The majority of patients have a slowly developing tumor that has been bothering them for months.

The costochondral arches and the sternum account for more than 60% of malignancies. As a result, all tumors developing from the costal cartilages should be treated as malignant at first and with broad resection. CXR frequently displays a poorly defined tumor that is destroying the cortical tissue. A well-defined, lobulated mass of soft-tissue attenuation with foci of extensive chondoid matrix calcification is seen on a 9 CT scan. Chondrosarcomas, on the other hand, can occur without calcification.

Lung metastases occur in 10% of individuals, either synchronously or metachronously. Because most chondrosarcomas are well-differentiated, histological distinction from chondromas can be difficult. For tumors 4 cm in diameter suspected of being chondrosarcomas, excisional biopsy should be conducted; incisional biopsies can be performed before bigger resections, especially in tumors that also involve the sternum or would require substantial reconstruction. In the vast majority of patients, definitive treatment consists of resection with wide margins of at least 4 cm on both sides, which is curative in the vast majority of cases, while local recurrences are uncommon.

Chemotherapy is largely unsuccessful, and radiation is usually reserved for malignancies that cannot be physically removed or when resection results in positive margins. The presence of metastases and the extent of resection determine the prognosis. The tumor's size and location have little bearing on prognosis. The overall 5-year survival rate ranges from 64% to 92 %.  Local recurrence occurs in up to 10% of individuals who have negative margins, compared to 75% of those who have inadequate margins.

Osteosarcoma 

Osteosarcoma is a type of malignant chest wall tumor that affects the long bones. It accounts for 10% to 15% of all malignant chest wall tumors. 19 It can afflict both young and old people, and it usually manifests as a fast growing mass. They can develop spontaneously or as a result of a preexisting bone lesion, such as Paget disease, or prior radiation therapy. They show immature bone in the form of tumor osteoid histologically. A sunburst pattern can be seen on CXR, while CT and MRI show a massive, heterogeneous mass that may contain necrosis, bleeding, or ossification.

Many patients have metastases when they first present, necessitating radiologic imaging of the lungs, bone, and liver. Chemotherapy and extensive excision are used to treat the condition. Metastases, most usually in the lung, occur in around 70% of cases, with a 5-year survival rate of 0%.

Preoperative chemotherapy has been utilized for osteosarcomas of the extremities because of the high rate of metastasis. The results have been varied, and due to the tumor's rarity, there is currently no universally recommended treatment regimen. Overall 5-year survival ranges from 15% to 20%, although nonmetastatic illness has a 50% 5-year survival rate. Metastases, tumor load, and chemotherapy response are used to predict outcomes.

Conclusion 

The chest wall protects our organs by acting as a barrier. The bone-and-tissue framework that surrounds important organs like the heart and lungs forms a cage. The spine, sternum, and ribs make up the chest wall. This framework can support a variety of malignancies. Some of them are primary tumors that start in the chest wall and might be benign or malignant. Others are secondary tumors that have spread (metastasized) from another part of the body to the chest wall. When tumors spread, they are virtually invariably cancerous.

A chest wall tumor can be diagnosed in a variety of ways. It necessitates a complete medical history as well as a physical examination. Chest wall tumors have a slow start of symptoms, with the majority of them being nonspecific. Patients frequently experience discomfort, edema, and aesthetic changes, prompting them to seek medical help.

Patients can expect more imaging to be required after a comprehensive history and physical examination, which usually begins with a chest radiograph. Additional imaging modalities, such as computed tomography or magnetic resonance imaging, may be required if there is a high suspicion of a chest wall tumor after obtaining a chest radiograph.

Furthermore, a tissue biopsy is required for a definite diagnosis. A surgical resection, maybe in combination with chemotherapy or radiotherapy, will be the gold standard of care. Creating an unified and complete treatment plan necessitates an interdisciplinary approach.