Continuing Education Activity

The chest wall refers to the structures surrounding and protecting the lungs, enclosed by the spine, and separated from the abdomen by the diaphragm. These structures include a myriad of tissues, including cartilage, bone, muscle, fascia, vasculature, lymphatic vessels, fat, and skin. Tumors of the chest wall subdivide into two categories, primary and secondary. Primary chest wall tumors arise from muscle, fat, blood vessel, nerve sheath, cartilage, or bone of the chest wall. Secondary chest wall tumors can be from direct invasion of breast carcinoma or lung carcinoma or metastases from a distant site of origin. Chest wall tumors on initial presentation can be difficult to recognize; however, a careful history and physical examination can lead to proper imaging and management. It is crucial to review the different imaging modalities available and what information can be gathered from ordering the right modality. A biopsy is the gold standard to make a definite diagnosis, and surgical techniques can be discussed with the appropriate risks and benefits addressed with the patient. Due to the wide range of specialties and providers who come across these chest wall tumors, it is important to develop an interprofessional approach to patient care.

Objectives:

• Outline which structures can be involved in chest wall tumors.
• Review the underlying etiology of chest wall tumors.
• Explain how to take a focused history and physical examination with selecting appropriate imaging for investigation.
• Describe how a well-coordinated interprofessional team approach to provide effective care to patients affected by chest wall tumors can improve outcome.

Introduction

The chest wall refers to the structures surrounding and protecting the lungs, enclosed by the spine, and separated from the abdomen by the diaphragm. These structures include a myriad of tissues, including cartilage, bone, muscle, fascia, vasculature, lymphatic vessels, fat, and skin. Tumors of the chest wall subdivide into two categories, primary and secondary. Primary chest wall tumors arise from muscle, fat, blood vessel, nerve sheath, cartilage, or bone of the chest wall. Secondary chest wall tumors can be from direct invasion of breast carcinoma or lung carcinoma or metastases from a distant site of origin.

Etiology

The etiology of chest wall tumors includes benign cellular or malignant overgrowth and proliferation, infectious, or inflammatory processes.

Primary chest wall tumors include tumors of the bone, muscle, fat, blood vessels, nerve sheaths, myositis ossificans, elastofibroma dorsi, and extra-abdominal desmoid tumors. Secondary chest wall tumors arise from metastases from other body organs.

It is currently unclear in the literature the precise cause of chest wall tumors; however, postulates are that genetics, diet, and lifestyle choices may have some effect in the development of these tumors.

Extra-abdominal desmoid tumors are aggressive fibromatosis, sometimes developing at the site of a previous thoracotomy.

Epidemiology

Research has not established the frequency of chest wall tumors in males versus females. The age of presentation varies; however, younger patients have smaller and more benign tumors, whereas older patients tend to have larger and more aggressive tumors.[1]

The primary chest wall tumors have an incidence of less than two percent of the population.[2][3] Chest wall neoplasms are either primary or metastatic, with a malignancy rate of about fifty percent and either symptomatic or asymptomatic, with about twenty percent found incidentally on chest radiograph.[4][5] Primary chest wall tumors represent five percent of all thoracic neoplasms.[2][3][6]

The sarcomas of the chest wall form in the cartilage, soft tissues, and bones of the chest cavity, including chondrosarcomas, osteosarcomas, rhabdomyosarcomas, plasmacytomas, malignant fibrous histiocytomas, and Ewing sarcomas. The most common primary malignant chest wall tumors are chondrosarcomas.

Approximately fifty to eighty percent of chest wall tumors are malignant, and fifty-five percent of these arise from bone or cartilage and forty-five percent from soft tissue.[4][7][8] Overall five-year survival after resection of primary chest wall neoplasms is approximately sixty percent.[7]. Recurrence can occur in up to fifty percent of patients, with a resultant five-year survival of seventeen percent.[7]

History and Physical

A careful history and physical examination are essential when evaluating a patient with a chest wall mass. Patients may complain of pain, soreness, swelling, impaired movement, a lump, or muscle atrophy. Physical examination may demonstrate noticeable swelling, and careful palpation may reveal underlying asymmetry of the chest wall and describe the texture of the tumor. Breath sounds may also be decreased. All of these result from the mass effect of the tumor itself and is not diagnostic for the underlying pathology for the tumor.

Evaluation

Following a thorough history and physical exam, the next step includes a chest radiograph that can be adequate initial workup to evaluate the size and extension of the tumor. The chest x-ray may provide a prompt evaluation of the lung for any direct invasion, may detect cortical bone destruction, or confirm the tumor is of boney origin; however, computed tomography is more sensitive than chest radiograph for verifying all of the above.[9] Magnetic resonance imaging is superior to computed tomography, especially in the evaluation of soft tissues. MRI can facilitate differentiation of neoplasms from normal chest wall structures and other disease processes due to infection and inflammation, and can fully characterize abnormalities by demonstrating the various internal components of complex lesions.[10] Positron emission tomography is used in the evaluation of chest wall tumors to stage disease, evaluate response to treatment, or detect recurrent disease.[11] Radiologic evaluation, despite their ability to distinguish between density and shape, is inadequate for definitive diagnosis; a biopsy is required to confirm the diagnosis. Lesions measuring less than five centimeters undergo excisional biopsy, and lesions greater than five centimeters either undergo needle aspiration or incisional biopsy.[5]

Treatment / Management

Treatment of chest wall tumors can be a clinical and surgical challenge. Surgical resection is the standard of care for benign tumors. The management of malignant tumors involves more of an interprofessional approach for optimizing functional outcomes. Wide tumor excision with negative margins is a critical predictor of local recurrence rates. It is also imperative that following resection, there is chest wall stabilization to avoid a negative impact on respiratory function.[12] A myriad of muscle flaps depending on the location and size of the defect are available to cover most of the chest wall defects, including pectoralis flap, latissimus dorsi flap, and rectus abdominis flap.[13] These procedures have high rates of perioperative morbidity and mortality due to incomplete resection, unsuccessful reconstruction, or in some cases, incorrect diagnosis. Surgery with resection has shown to be the best option for primary tumors and a selection of secondary tumors of the chest wall, and may even be curative.[14][15] Combining surgery with radiation therapy and/or chemotherapy may be indicated but depends on the histopathology of the tumor.

Differential Diagnosis

The differential diagnosis for chest wall tumors is exponential. The differential includes benign and malignant lesions, which can be the local extension of an adjacent disease. It can also include local manifestations of inflammatory or infectious etiologies. The following criteria can limit the differential of chest wall tumors: overall prevalence and characteristic clinical features, mineralization patterns, the location at the chest wall, and intrinsic magnetic resonance imaging characteristics that correspond with histopathologic findings.[16]

Most Common Benign Tumors[3]

• Osteochondromas
• Chondromas
• Fibrous dysplasia
• Desmoid tumors

Most Common Malignant Tumors[7]

• Soft tissue sarcomas
• Chondrosarcomas
• Ewing sarcoma

Prognosis

Prognosis is entirely dependent on the pathologic etiology underlying the tumor. Benign pathology requires surgical intervention if mass effect from the tumor causes pain, neurovascular entrapment, or cosmetic complaints. These patients with surgical resection have a good prognosis. However, patients with a malignant pathology have a guarded prognosis. A multidisciplinary approach is necessary; yet, metastatic disease has a comparatively poor prognosis.

Complications

Significant complications are likely if patients opt-out from surgery or are not surgical candidates. These patients may suffer from increased pain, swelling, neurovascular entrapment leading to ischemia and paresthesias, and cosmetic distortion of the body habitus. If patients elect for surgery, they are at risk for surgical complications, including but not limited to nerve damage, vascular ligation, and respiratory compromise. Postoperatively patients require pain management and pulmonary supportive care. The morbidity and mortality are relative to the depth and extent of invasion, as well as the underlying natural etiology of the tumor. Cell type is important and influences oncologic outcomes and overall survival; the recurrence rates remain high with more aggressive histology.

Deterrence and Patient Education

The diagnosis of a chest wall tumor is multifold. It requires a thorough history and physical examination. Chest wall tumors have insidious onset of symptoms, most of which are nonspecific. Patients usually notice pain, swelling, and cosmetic derangement, which prompts them to visit a physician. After a thorough history and physical, patients can expect further imaging necessary, usually starting with a chest radiograph. If there is high suspicion for a chest wall tumor after obtaining a chest radiograph, additional imaging modalities, including computed tomography or magnetic resonance imaging, may be required.

Furthermore, definitive diagnosis relies on a tissue biopsy. The ultimate standard of care will be a surgical resection, potentially in combination with chemotherapy or radiotherapy. An interprofessional approach is vital to creating a cohesive and comprehensive treatment plan.

Enhancing Healthcare Team Outcomes

Diagnosis of chest wall tumors for healthcare providers and other healthcare professionals requires a high index of suspicion despite nonspecific history and physical examination. Coordination with radiology is imperative as patients must undergo chest radiographs, computed tomography, magnetic resonance imaging, and/or PET scan. An interprofessional approach including but not limited to: primary care, nursing staff, radiology technicians, radiologists, pharmacists, interventional radiologists, pulmonologists, oncologists, and surgeons will be involved in a majority of the cases of chest wall tumors. Operative and perianesthesia nurses participate in care and monitor patients. They also are involved in patient and family education. The patient's prognosis centers around the underlying pathology of the disease; however, having an interprofessional approach to the patient will help expedite management and prevent further morbidity and mortality. [Level 5]