Chest Wall Sarcoma
Chest wall Sarcoma is a rare, malignant neoplasm of mesenchymal or connective tissue origin. Primary malignant tumors rarely show symptoms as they grow slowly. Primary tumors originate in the chest wall, whereas secondary tumors spread or metastasize to the chest wall from other sites in the body, such as adjacent breast or lung cancer. Primary tumors may be benign and/or malignant.
Sarcomas constitute 1% of all adult malignancies. The chest wall in the human body plays an indispensable role in safeguarding vital organs, mainly the lungs and the heart. It is a cage-like structure formed by bones and tissues. The major bones of the chest wall are the ribs, sternum, and spine. Chest wall tumors can develop in the soft tissues, cartilage, and bones. Additionally, around 10-15% of sarcomas have been reported to appear in the chest wall which protects the delicate organs like the heart including rare soft-tissue primary chest wall sarcoma.
Generally, the common presentation of chest wall sarcoma is a slowly growing mass, which is asymptomatic, but subsequently becomes large enough to compress or invade the surrounding structures, having an average size of about 15 cm at the time of diagnosis.
Chest wall sarcoma involves soft tissue and skeletal structures of the thorax region. The tumors originate from diverse constructions of the thoracic wall and may occur in two main tissue types either a single tissue type or a combination of tissue types. Furthermore, the extension of the tumor mass may lead to pain. The major types of chest wall sarcomas are chondrosarcoma, osteosarcoma, Ewing’s sarcoma, plasmacytoma, malignant fibrous histiocytoma, and rhabdomyosarcoma. The most common primary chest wall tumors are malignant chondrosarcomas.
In the USA, a recent report states that there were an estimated 78,527 cases of sarcomas with an overall incidence of 7.1 cases per 100,000 people. This figure increased from 6.8 in 2002 to 7.7 in 2014. The population constitutes approximately an estimated 55% of chest wall sarcoma. The study also emphasized that soft tissue sarcomas are more often observed than bone sarcomas. Similarly, in Europe, the trend also showed a greater frequency of soft tissue sarcomas (84%) over bone sarcomas. Overall five-year survival after resection of primary chest wall neoplasms is approximately 60%. The recurrence can occur in up to 50% of patients after resection.
The percentage of Indian patients who survive a chest wall tumor is approximately the same as the western population. Chest wall tumors are becoming more common in India due to rapid industrialization.
Chest wall sarcoma comprises a heterogeneous group of lesions that are challenging to diagnose and treat. The protocol of diagnosis of a suspected chest wall tumor includes a careful history, proper physical examination, and a chest X-ray.
The foregoing may be followed by advanced imaging modalities such as computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET). After a thorough patient history, and physical examination, the patient undergoes a chest X-ray that is sufficient to evaluate the size and extension of the tumor. The chest X-ray also provides a prompt evaluation of the lungs for any direct invasion, may detect cortical bone destruction, confirm if the tumor is of bony origin, as well as differentiate malignant from benign chest wall tumors. However, computed tomography is more sensitive than chest radiographs for evaluating all of the foregoing. For the evaluation of soft tissues, magnetic resonance imaging (MRI) is superior to computed tomography. MRI helps to differentiate neoplasms from normal chest wall structures and other disease variations developed due to infection or inflammation, and can also fully elucidate the various internal components of complex lesions. PET scan is utilized to identify the stage of the disease, evaluate response to treatment, or detect recurrent disease. Though all these radiological evaluations can help to ascertain the density and the shape of the tumor, they are not adequate for a definitive diagnosis, however, a biopsy is essential to confirm the diagnosis. Excisional biopsy is performed for lesions measuring less than five centimeters, and needle aspiration or incisional biopsy is done for lesions greater than five centimeters. Several subtypes of chest wall sarcomas display a characteristic clinical picture with distinct morphological and immune histochemical profiles that aid in diagnosis. Additionally, molecular testing with reasonably high sensitivity by fluorescence in situ hybridization (FISH) and polymerase chain reaction (PCR) molecular tools can help confirm a suspected diagnosis and is also useful for high-grade lesions where the morphology or immunohistochemistry (IHC) profile may be non-specific.
Surgical resection is the standard of care for benign tumors. The handling of malignant tumors involves a more interprofessional approach to optimize functional outcomes. The treatment plan takes into account, the type of chest wall tumor of the patient, its size, and its location. Malignant chest wall tumors usually require a combination of chemotherapy, radiation therapy, and/or surgery. Wide tumor excision with negative margins is preferred as they impede local recurrence. If surgery is required, reconstruction of the chest wall and the soft tissue (ribs, muscles, and skin) becomes imperative to ensure that the chest looks and functions normally.
Various types of muscle flaps are employed depending on the location of resection to cover most of the chest wall defects, such as the pectoralis flap, latissimus dorsi flap, and rectus abdominis flap. Other items used for reconstruction include prosthetic mesh and titanium implants in combination with strong synthetic or biological mesh. Full-thickness chest wall resection has been reported to improve survival, prolong palliation, and cure. However, such surgical procedures are at times accompanied by perioperative morbidity and mortality due to incomplete resection, unsuccessful reconstruction, or in some cases, incorrect diagnosis. Surgical resection along with reconstruction has been identified as the best option for primary tumors, and these procedures may even be curative. Combining surgery with radiation therapy and/or chemotherapy may be indicated in certain cases but it depends on the histopathology of the tumor.
Quality of life
The quality of life postoperatively is a major concern for patients with these tumors. These chest wall sarcoma patients may suffer from enhanced pain, swelling, and neurovascular entrapment that may lead to, paresthesia (tingling or prickling sensation), and cosmetic distortion.
Other surgical complications include vascular ligation and respiratory compromise. Pain management, as well as pulmonary supportive care, is inevitable in post-operative patients. The location and extent of the tumor determine the severity of complications after surgery. An interdisciplinary team-based approach is needed for the complete management of chest wall sarcoma patients.
The team includes nursing staff, radiology technicians, radiologists, interventional radiologists, pharmacists, pulmonologists, surgeons as well as oncologists. In addition, operative and paranesthesia nurses are also needed for routine care and monitoring of patients. Family education is another vital part of patient management. Therefore, such an interprofessional approach will aid in the prevention of further morbidity and mortality.
Chest wall sarcomas are an unusual and uncommon onset. Surgery is the mainstay of treatment for limited disease and is often curative, so management should ideally involve a multidisciplinary approach. The extent of the disease determines whether radiotherapy and chemotherapy are used to augment treatment. A desirable prognosis is provided by prompt diagnosis and management. As a result, standard guidelines for the diagnosis of chest wall sarcomas are required for proper management.