Chondrosarcoma is the most common primary malignant bone tumor of the chest wall. It is more common in males and in the age group of 30 to 60 years. It usually presents on the anterior chest wall, arising from the costochondral arches or sternum. It may occur as the result of malignant degeneration of a benign chondroma. Both chondrosarcomas and benign chondromas present as painful, slow-growing, hard, fixed, and nontender anterior chest wall masses. Radiologic features of both tumors may be indistinguishable; therefore, a histologic diagnosis is required to assess malignancy. Chondrosarcoma has the appearance of a large expanding mass containing chondroid-type calcifications accompanied by a significant soft tissue component that causes distraction of the bone (Fig. 134-1). Current therapy for chondrosarcoma requires adequate surgical excision with a margin of at least 4 cm. Chemotherapy is ineffective, and radiation therapy is used only for patients with tumors that are either not amenable to surgical resection or have positive resection margins. In the Mayo Clinic series,6 the overall survival rate at 5 years was 92%. The recurrence rate for patients with adequate surgical margins was 10%, compared with 75% in patients with inadequate surgical margins. The 5-year survival rate for patients with adequate surgical margins was 100%, compared with 50% in patients with inadequate surgical margins. Inadequate surgical margins of resection were associated with a significantly decreased overall survival and a higher chance of local recurrence.
Chest wall chondrosarcoma in a 62-year-old man. A. Nonenhanced CT scan shows a large mass that arises from the costochondral junction. The mass extends into the subcutaneous tissue and compresses and displaces the heart. B. Axial gadolinium-enhanced T1-weighted MRIs show that the mass is heterogeneous and enhances. (Reproduced with permission from Gladish GW, Slaboff ABM, Munden RF, et al. Primary thoracic sarcomas. Radiographics. 2002;22:621–637.)
Osteosarcoma is much less common than chondrosarcoma among primary bony chest wall malignancies. Although osteosarcoma represents the most common primary malignant tumor arising in bone, only 3% arise from the chest wall (Fig. 134-2). Osteosarcomas occur in a bimodal age distribution. Adolescents and young adults are affected most commonly, with a smaller subgroup of patients developing osteosarcoma after age 40. It commonly presents as a rapidly enlarging, painful mass. In older patients, secondary osteosarcoma may develop in preexisting diseases of the bone, such as Paget disease, bone infarction, sites of previous radiation, and so forth. Metastatic disease (lung mostly) is present in one-third of patients at initial presentation, and over two-thirds of patients will develop metastases at some point. For this reason, perioperative chemotherapy is standard treatment, with improved 5-year survival of up to 50% for extremity osteosarcoma. Given that primary osteosarcoma of the chest wall is such a rare tumor, it is permissible to extrapolate the survival benefit of chemotherapy from extremity osteosarcoma, with the exception that tumors presenting in diverse sites may respond differently. Radiotherapy is largely ineffective in treating osteosarcoma.
A. Osteosarcoma in a 43-year-old man. Contrast-enhanced CT scan shows a left-sided chest wall mass with an osteoid matrix (arrow), a finding characteristic of chest wall osteosarcoma. B. Osteosarcoma in a 52-year-old woman. Contrast-enhanced CT scan shows a heterogeneous chest wall mass without an ossified matrix. (Reproduced with permission from Gladish GW, Sabloff BAM, Munden RF, et al. Primary thoracic sarcomas. Radiographics. 2002;22:621–637.)
Plasmacytoma is a rare tumor that consists of sheets of plasma cells of variable maturity. The histologic features are indistinguishable from those found in multiple myeloma. The presence of multiple myeloma is excluded by the absence of multicentric disease and plasma cell infiltration of the bone marrow. The most common sites are the vertebral column in approximately 50% of the patients, with tumors of the ribs and sternum accounting for 10% to 15% of cases. It is twice as common in men, and it may occur in any age group. The most common mode of presentation in the chest wall is pain without a palpable fixed mass. Radiologic testing usually shows a solitary osteolytic or punched-out bone lesion without evidence of primary tumor. Systemic manifestations such as anemia, hypercalcemia, impaired renal function, immunoglobulinopathy, or elevated Bence–Jones protein are not expected in this disease.
The role of surgery in the management of solitary plasmacytoma of the chest wall is limited to diagnostic biopsy in most settings. Definitive local radiation is the treatment of choice, providing local control in over 90% of patients. Chemotherapy is used if there is evidence of progression to multiple myeloma, such as may occur in 75% of patients.
Ewing sarcoma is the most common malignant tumor of the chest wall in children and young adults. It is a small round cell sarcoma that occurs primarily in flat bones and in the midshaft of long bones. Approximately 300 new cases of Ewing sarcoma occur each year worldwide. Only 15% of these cases occur in the chest wall. It arises almost exclusively in white populations. Two-thirds of all cases of Ewing sarcoma are seen in persons younger than 20 years. Over the past two decades, the 5-year survival rate has improved dramatically from 10% to 50% in different series. The improvement in survival is attributed to the availability of newer chemotherapy regimens to treat systemic disease. Most patients will develop metastasis at some point in the course of their disease. Because of the typical systemic nature of this tumor, chemotherapy alone with some form of local therapy is the standard. Shamberger et al.7 compared the completeness of resection and disease-free survival in patients undergoing initial surgical resection versus those treated with neoadjuvant chemotherapy followed by resection, radiotherapy, or both. Patients with positive resection margins received radiotherapy. They reported 98 patients with Ewing sarcoma of the chest wall. Their 5-year disease-free survival was 56% and did not differ based on timing of surgery or type of local control. However, neoadjuvant chemotherapy decreased the percentage of patients needing radiation therapy. Seventy percent of the patients undergoing initial surgery received radiotherapy compared with 40% of patients who had neoadjuvant therapy and then surgery.
Among primary chest wall tumors, chest wall lymphoma is uncommon, accounting for fewer than 2% of primary tumors. Few cases of primary malignant lymphoma arising from the pleura, the rib, or the sternum have been reported. Hsu et al.8 reported their experience in seven patients with non-Hodgkin lymphoma presenting as a solitary chest wall mass. For three patients with chest wall lymphoma as the only site of disease, complete surgical resection followed by chemotherapy was carried out with satisfactory outcome. Most of the patients had B-cell lymphoma. Histologic cell types reported by others include Hodgkin lymphoma and other non-Hodgkin lymphomas.
The primary treatment of choice for lymphoma with or without chest wall involvement is chemotherapy and radiation. It is debatable whether surgical resection followed by adjuvant chemotherapy can provide a survival benefit in some patients in whom the chest wall lymphoma is the only site of disease.
Primary soft tissue sarcomas of the chest wall are uncommon. Of the 11,000 new cases of soft tissue sarcoma diagnosed annually in the United States, fewer than 10% arise in the chest wall. A few studies have suggested that soft tissue sarcomas of the chest wall and primary extremity sarcomas have similar prognoses. Both groups have better survival rates than observed in patients with retroperitoneal, head and neck, and visceral soft tissue sarcomas. Gross et al.9 reviewed 55 surgically treated patients with chest wall soft tissue sarcomas. The median age of their patients was 47.5 years, with a male predominance. Painless mass was the most common initial presentation. The median duration of symptoms was 12 months and is longer than that reported for patients with tumors in other sites. The tumor diameter in most patients was larger than 9 cm. The overall 5-year survival rate was 87.3%. The disease-free survival rates at 5 and 10 years were 75% and 64%, respectively. Tumor size less than 5 cm, low histologic grade, and wide surgical resection were determinants of a better disease-free survival.
Undifferentiated Pleomorphic Sarcoma (Malignant Fibrous Histiocytoma)
Malignant fibrous histiocytoma, now officially referred to as undifferentiated pleomorphic sarcoma, is the most commonly observed soft tissue sarcoma in adults. It generally develops after radiation therapy and may originate in the extremities, retroperitoneum, peritoneal cavity or occasionally the chest wall. It is usually a disease of advanced age and is seen during the sixth and seventh decades of life. It does not have any strong gender preference. In most instances, the patient is asymptomatic, and the appearance is that of a well-defined, lobulated or regular soft tissue mass. On CT scan, histiocytomas enhance heterogeneously with contrast material and rarely contain calcifications (Fig. 134-3). The diagnosis is confirmed by histopathologic and immunohistochemical analysis of tumor tissue. Such sarcomas are highly aggressive and surgery remains the cornerstone of treatment whenever possible. Wide excision with chest wall reconstruction using synthetic mesh or flap reconstruction is advocated for chest wall involvement as these tumors are generally not responsive to chemotherapy or radiation therapy as sole treatment modalities.10–13
Malignant fibrous histiocytoma of the chest wall in a 76-year-old woman. A. The chest x-ray shows a large extraparenchymal mass in the right upper hemithorax. MRIs show that the mass has heterogeneous signal intensity and marked enhancement on B. Axial T1-weighted C. gadolinium-enhanced T1-weighted and D. fat desaturation T2-weighted images. (Reproduced with permission from Gladish GW, Sabloff BM, Munden RF, et al. Primary thoracic sarcomas. Radiographics. 2002;22:621–637.)
Rhabdomyosarcoma is a childhood tumor that has a bimodal age distribution. In adults, it is seen after age 50 and occurs more often in males. It can originate either from chest wall striated muscles or the diaphragm. Prognosis depends on the histopathologic subtype. Alveolar type has a less favorable prognosis than the embryonic and pleomorphic subtypes. Since these tumors can remain clinically silent, they may have already reached large dimensions by the time of diagnosis. There may be necrosis and cystic areas within the mass.
Fibrosarcoma originates from the connective tissue found in the chest wall. It is the most common cell type among soft tissue sarcomas of the chest wall in children and young adults. It forms a large mass, and on CT scan, foci of calcifications or ossification may be observed.
Desmoid tumors are slow-growing mesenchymal neoplasms without metastatic potential. They most frequently occur during the second or third decades of life, but can be seen in all age groups. Although the etiology is unknown, genetic predisposition in patients with familial adenomatous polyposis and association with pregnancy have been recognized. Histologically they consist of small numbers of spindle cells with rare mitoses and surrounded by copious stoma. They appear to arise from musculoaponeurotic tissue. Desmoid tumors present high tendency toward local infiltration and invasion. Invasion to surrounding structures results pain, functional limitation, deformity, and even death if vital organs become compromised. Although distant spread has not been documented in long-term follow-up studies, these tumors have a strong propensity to recur locally after resection. In a series of 53 patients who underwent resection for desmoid tumor of the chest wall, Abbas et al.14 found that the 5-year overall probability of developing a local recurrence was 37.5%.
Surgery remains the gold standard of treatment and achieving microscopic negative margins is the goal of the surgical resection. Nevertheless, it should be noted that while most studies in the past suggested that positive resection margins correlated with high recurrence rate, more recent papers with large number of cases have been questioning this assumption. Moreover, wide negative margins do not further decrease the recurrence rate when compared to microscopically negative margins, whether they frequently compromise functional result. Melis et al. reviewed the current evidences for multimodality management of desmoids and presented the following algorithms: complete surgical excision with negative margins is the goal of treatment but, this should not be achieved at the cost of functional compromise. The most radical example for that might be in a case where upper extremity amputation is needed in order to achieve negative margins. The recommendation in this situation is to reserve amputation only for patients whose limb is already nonfunctional or embrace other tumor related complications. If residual tumor is left behind, treatment options include: reexcision (if this can be safely performed), adjuvant radiation or chemotherapy, or observation. In patients with recurrence, reexcision can be followed by radiation therapy, especially if residual tumor is left behind or if the tumor recurred after complete initial excision.15
Patients who have multiple locoregional recurrences despite adequate local therapy are considered for systemic therapy. Additional indications for systemic therapy include unresectable tumors. Options for systemic therapy include anti-inflammatory agents, hormonal agents (e.g., antiestrogens and androgens), systemic chemotherapy, and more recently good tumor response has been observed with kinase directed therapies such as Imatinib and Sorafenib.16
Sarcomas are a rare but recognized complication of radiotherapy for chest malignancies and are associated with poor prognosis. In 1948, Cahan et al.17 established the criteria for the diagnosis of radiation-induced sarcoma (RIS). These criteria are still in use today and include (1) history of radiotherapy, (2) asymptomatic latency period of several years, (3) occurrence of sarcoma within a previously irradiated field, and (4) histologic confirmation of the sarcomatous nature of the post irradiation lesion. The incidence of RIS is considered to be associated with radiotherapy dose. A shorter latency period also was found to be associated with high-dose radiotherapy. Indications for the initial irradiation are most commonly breast carcinoma and lymphoma, but RIS may develop regardless of the initial tumor type. In a review of 351 patients with primary malignant tumors of the chest wall, Schwarz and Burt18 identified 21 patients with lesions (6%) arising in an irradiated field. A third of the patients in this study with primary osteosarcoma had a tumor arising in the field of prior irradiation (11 of 38 patients). There was no significant difference in survival between malignant chest wall tumors arising in an irradiated field and those arising de novo. The authors concluded that since the outcome after operative therapy appeared to be similar, patients with tumors arising from an irradiated field should be offered identical treatment to those with tumors arising de novo.
In a large-scale series, Kirova et al.19 reviewed records of 13,472 patients with breast carcinoma who were treated with megavoltage radiotherapy. Of those, 27 patients (0.2%) fulfilled the Cahan criteria. The latency period ranged from 3 to 20 years. Histologic evaluation identified most commonly angiosarcoma (48%), followed by osteosarcoma, undifferentiated sarcoma, histiocytoma, leiomyosarcomas, fibrosarcoma, rhabdomyosarcoma, and myosarcoma. The cumulative RIS incidence was 0.07% at 5 years, 0.27% at 10 years, and 0.48% at 15 years. Standardized incidence ratios were 10.2 for irradiated patients compared with 1.3 for nonirradiated patients. The 5-year actuarial survival rate after diagnosis of RIS was 36%. Since the response to chemotherapy tends to be poor, the treatment for RIS is not different from that for other primary sarcomas and involves a wide resection.
Metastatic Tumors to the Chest Wall
Metastatic disease accounts for 20% to 30% of all chest wall neoplasms. It can occur within the bony thorax or the soft tissues surrounding it. Owing to advances in cancer treatment that prolong survival, there has been a noticeable increase in the prevalence of bone metastasis. Consequently, indications for surgical treatment were expanded mainly for pathologic or high-risk fractures of the limb bones and for compression fractures in the spine. The indication for surgery of a solitary metastasis for which extended survival may be anticipated is controversial. Some thoracic surgeons regard solitary metastasis as a marker for micrometastatic disease and suggest other treatment modalities, whereas others support resection for palliation and possible survival benefit. Manabe and colleagues20 reviewed their experience with surgical treatment of bone metastasis. They reported long survival for patients with metastases from thyroid, breast and kidney, with median survival of 56, 30, and 30 months, respectively, and short survival for those with metastases from lung and liver carcinoma (median 8 and 13 months, respectively). These findings should be considered when selecting patients for wide resection.
In a review of 703 patients who developed metastatic bone lesions after beginning treatment for breast cancer, Koizumi et al.21 found that 41% (289) had solitary skeletal metastasis. The sternum was the most common site for solitary skeletal metastasis (98 of 289, or 34%). The patients with solitary skeletal metastasis lived longer than those with multiple metastatic bone lesions (p <0.001). Solitary sternal metastatic lesions remained solitary longer than solitary lesions in anatomic regions other than the sternum (p <0.001) but did not lengthen patient survival times.
Durr et al.22 retrospectively studied the effect of surgical therapy on a series of 70 patients with breast cancer who were treated surgically for metastasis of the bone. Surgical treatment involved: palliative procedures, radical resections, and biopsies. Of the six patients who were radically resected for solitary bone lesions, five developed systemic progression of the disease. The authors concluded that although patients with solitary bone lesions have a better prognosis, with a 39% chance of living 5 years, radical resection does not significantly improve survival.
Fuchs et al.23 who retrospectively analyzed the survival rate of 60 patients with solitary bony metastasis from renal cell carcinoma, came to a similar conclusion. Thirteen patients had wide resection, 20 had local stabilization, and 27 patients had no surgical treatment but had adjuvant treatment alone. There was no survival advantage for patients who had a wide resection of the lesion compared with patients who had intralesional resection or intramedullary stabilization alone. These results indicate that wide surgical excision of a solitary bony metastasis from renal cell carcinoma is not mandatory to improve survival. However, wide resection of metastatic lesions may be necessary to prevent local disease progression and complications.