Chest wall tumors are uncommon malignancies, whether primary or secondary in nature. Nevertheless, nearly every thoracic surgeon eventually will be asked to evaluate one of these tumors in clinical practice. It is estimated that only 500 index cases of primary malignant chest wall tumors occur in the United States annually,¹ in addition to secondary chest wall tumors, which are, most notably, those related to recurrent breast cancer. Given this relatively low incidence, no one surgeon or surgical group could be expected to have an extensive experience with this tumor type. Having a working knowledge of the surgical principles underlying the management of uncommon chest wall tumors therefore is all the more relevant.

The more common primary chest wall tumors are listed in Table 135-1. Although most of these tumors in the pediatric population are malignant, only approximately half of these tumors are malignant in adults.

The overriding technical principle of chest wall surgery is similar to that of tracheal surgery. Specifically, the procedure consists of two separate but equally important parts – resection and reconstruction – and the technical considerations of each must be assessed independently.

With regard to resection, it is imperative to establish first whether the tumor is primary or metastatic, and if primary, whether it is malignant or benign. This determination may be clear from the patient’s history and certain radiographic characteristics of the tumor, but a tissue diagnosis is important for several reasons. If the tumor is benign, an overly aggressive resection and complex reconstruction may not be needed. Alternatively, if the tumor is malignant, one of several different treatment strategies may be required. For example, some of these tumors (e.g., osteosarcoma and plasmacytoma) are best treated nonoperatively initially. Other primary malignant chest wall tumors (e.g., primitive neuroectodermal tumors and some sarcomas) may benefit from induction therapy before a planned surgical resection. Thus, establishing a tissue diagnosis is the first important step in the treatment algorithm for chest wall tumors.

The diagnostic technique selected for biopsy also must adhere to standard oncologic principles. The biopsy site must be placed in a location that can be incorporated into the planned resection specimen. Most chest wall lesions that arise from bone, cartilage, or soft tissues of the chest wall are amenable to diagnosis by core needle biopsy. On the rare occasion that core needle biopsy is not possible or is nondiagnostic, incisional biopsy can be performed, provided that the incision is placed within the margins of the resection specimen, as mentioned earlier. Excisional biopsy also can be used for smaller lesions (<3 cm), and if such lesions are later determined to be malignant, a wider local excision that incorporates the old surgical scar can be performed as a separate procedure.

Resectability represents another important oncologic principle, and it is addressed after the tissue diagnosis has been established. Typically, the determination of resectability involves a radiographic assessment of the involved anatomic structures. If it is determined that resection is possible, the surgeon must decide how the resulting skeletal defect will be handled and whether any additional soft tissue coverage will be required. If it is likely that a muscle flap or omentum or a split-thickness skin graft will be needed, a careful assessment of the suitability of the various tissues and flaps should be made. This assessment is often made with the assistance of a plastic surgeon both familiar and comfortable with soft tissue reconstruction of chest wall defects. The planned resection strategy should ensure a complete R₀ resection if at all possible. With advances in chest wall reconstruction (both skeletal and soft tissue) and some intraoperative creativity, nearly any postresection chest wall defect can be managed successfully. Thus the size of a resulting chest wall defect has little, if anything, to do with the resectability of the tumor or extent of the planned resection.

From both a technical and an oncologic perspective, it is important to have an adequate surgical margin around the tumor. This typically requires resection of one uninvolved rib above and below the ribs invaded by the malignant tumor. The medial and lateral margins of resection should be at least 4 to 6 cm. Several reports have documented the importance of a wide local excision (margin of at least 4 cm) resulting in increased disease-free and overall survivals.^2,3 For tumors located in the sternum, the sternum must be removed, although the manubrium may be spared if the tumor affects only the body. The converse is true for isolated manubrial lesions. Additionally, sternal tumors require removal of at least 2 to 3 cm of costal cartilage laterally to ensure R₀ resection. If possible, the upper aspect of the manubrium should be preserved because it provides for the majority of anterior chest wall stability.⁴ Resection of overlying soft tissue and skin is mandatory if there is any suspicion of tumor involvement.

An essential part of the treatment algorithm is the need for case discussion, including careful review of the pathology in the context of a multidisciplinary tumor conference. Such discussion provides the opportunity for medical and radiation oncologists to examine their potential roles in the treatment plan. This exchange is particularly important if either induction chemotherapy or catheter placement for intraoperative brachytherapy is being considered. In addition, multidisciplinary review of the staging studies and pathology ensures the appropriateness of the treatment plan.

Most benign and malignant chest wall tumors are managed with complete surgical resection. For example, the primary treatment for chondrosarcoma, the most common malignant chest wall tumor, is wide local excision. These lesions are highly chemoresistant and have limited sensitivity to radiation. Selected tumors, however, are better managed with adjuvant therapies.

Induction chemotherapy appears to play a role in the management of some primary chest wall tumors. On the basis of data from extremity sarcoma studies, preoperative Adriamycin-based chemotherapy is used in patients with primitive neuroectodermal tumors and for some soft tissue sarcomas.^5,6 After restaging, wide surgical excision is performed, and many patients complete an additional course of adjuvant chemotherapy secondary to the high rate of systemic failure observed with surgery alone for tumors of this type.⁷

Adjuvant external beam radiation for all primary chest wall tumors typically is reserved for R₁ or R₂ resections or in cases where the margin, while negative, lies close to the tumor.⁸ For instance, the rate of recurrence with an R₁ resection of a desmoid tumor of the chest wall is 90%.⁹ In contrast, patients with R₀ resection for a desmoid tumor have a recurrence rate of 27%, and none of the patients who received adjuvant radiation with an R₀ resection developed a recurrence. This suggests that adjuvant radiation may be reasonable in all patients with a desmoid tumor regardless of margin status. The role of adjuvant brachytherapy in the treatment of soft tissue sarcomas of the chest wall is limited by a greater incidence of regional recurrences compared with in-field recurrences. Thus external beam therapy, which covers a larger region of the tumor bed, is preferred.¹⁰ On the other hand, brachytherapy is a useful adjunct to surgical resection for a tumor that has been irradiated previously.

For several tumors, the role of surgery is purely diagnostic. Plasmacytoma is a prime example. These tumors are associated most commonly with multiple myeloma, and even if the patient has no current clinical or laboratory evidence of the disease, he or she frequently develops the disease years later. Therefore, isolated chest wall plasmacytomas typically are treated with external beam radiation alone with very good results. Similar to plasmacytomas, osteosarcomas are often metastatic deposits from long bone (e.g., tibia, femur, or humerus) primaries, although primary chest wall osteosarcomas can arise from the ribs. Regardless of the origin, once the diagnosis is established, both types are treated initially with Adriamycin-based multidrug chemotherapy. Residual primary chest wall osteosarcomas should be resected with wide margins after restaging studies demonstrate the absence of metastatic disease.

After the tissue diagnosis has been established, the patient must be assessed for operability. This process necessitates evaluation of the patient’s cardiopulmonary status, age, comorbidities, and performance status.

Once it is clear that the patient is operable, a careful radiographic assessment of the stage and local extent of the tumor is performed. All patients need a CT scan of the chest and upper abdomen, and many will have a PET scan as well. There are few data on the use of PET scans for primary chest wall tumors, particularly those arising from bone or cartilage, but extrapolation from other solid-tumor malignancies suggests that they may be beneficial, particularly with PET-avid tumor types known to metastasize early. Pertinent information supplied from the CT images includes the locoregional extent of the tumor, as well as its proximity to the mediastinum, vertebral bodies, and diaphragm. CT scan also may suggest the presence or absence of metastatic disease in the lung, liver, or adrenals. MRI is reserved for tumors located close to the brachial plexus and subclavian vessels and to resolve any questions about direct involvement of the great vessels or extension into the intervertebral foramina. For soft tissue tumors of the chest wall, it may be difficult to know with certainty if there is bony involvement. No roentgenographic study can definitively include or exclude bone involvement. If the patient has chest wall pain at the tumor site, there is at least an 80% likelihood that bone is involved.