We studied the clinicopathologic and immunohistochemical features of 20 cases of proximal-type epithelioid sarcoma to identify prognostic factors. The 20 patients ranged in age from 13 to 80 years (mean, 40 y); 12 patients were male and 8 were female. The tumors presented as deep soft-tissue or subcutaneous masses on the inguinal region in five, the thigh in four, the vulva in three, the axilla in three, and one each in the flank, chest wall, back, hip and perineum. The tumors ranged from 2 to 16 cm at their greatest diameter (mean: 7.8 cm). Histologically, 12 tumors (60%) were classified as the large-cell subtype, characterized by sheets of large cells with prominent nucleoli resembling poorly differentiated carcinoma, and a frequent rhabdoid phenotype, six (30%) were classified as the conventional subtype, and two ( Epithelioid sarcoma, first described by Enzinger in 1970 (1), is a rare soft-tissue sarcoma typically presenting as a subcutaneous or deep dermal mass in distal portions of the extremities of adolescents and young adults. Microscopically, most tumors are characterized by a granuloma-like pattern: nodules of spindled and epithelioid cells circumscribe areas of central hyalinization and necrosis. Fibrous histiocytoma-like and angiomatoid subtypes have also been reported as less common histologic variants (2, 3). Patients often develop multiple local recurrences of long duration, with subsequent metastases in 30 to 50% of cases (4). A more aggressive "proximal" or largecell type has been described in rare cases to occur as a deep-seated soft-tissue mass at proximal body sites and to show sheets of large cells with prominent nucleoli resembling a poorly differentiated carcinoma and a frequent rhabdoid phenotype (5). Thus, this tumor must be distinguished from other epithelioid lesions, such as extrarenal rhabdoid tumor, synovial sarcoma, angiosarcoma and melanoma, and its prognostic factors have not yet been fully investigated. We therefore studied 20 cases of proximal or axial epithelioid sarcoma by immunohistochemical analysis to examine the clinicopathologic features that correlate with a poor outcome in patients with these tumors.

Benign chest wall tumors are uncommon lesions that originate from blood vessels, nerves, bone, cartilage, or fat. Chest radiography is an important technique for evaluation of such tumors, especially those that originate from bone, because it can depict mineralization and thus indicate the diagnosis. Computed tomography (CT) and magnetic resonance (MR) imaging are helpful in further delineating the location and extent of the tumor and in identifying tumor tissues and types. Although the radiologic manifestations of benign and malignant chest wall tumors frequently overlap, differences in characteristic location and appearance occasionally allow a differential diagnosis to be made with confidence. Such features include the presence of mature fat tissue with little or no septation (lipoma), the presence of phleboliths and characteristic vascular enhancement (cavernous hemangioma), evidence of neural origin combined with a targetlike appearance on MR images (neurofibroma), well-defined continuity of cortical and medullary bone with the site of origin (osteochondroma), or fusiform expansion and ground-glass matrix (fibrous dysplasia). Both aneurysmal bone cysts and giant cell tumors typically manifest as expansile osteolytic lesions and occasionally show fluid-fluid levels suggestive of diagnosis.

The chemokine, CXCL12, and its receptor, CXCR4, have recently been shown to play an important role in metastasis of several kinds of carcinoma. It has also been demonstrated that VEGF regulates both the expression of CXCR4 and invasiveness in breast cancer cell lines. We compared the immunohistochemical expression of CXCR4 and VEGF between the primary site and a concordant pulmonary metastatic site in 30 osteosarcoma patients, all of which had undergone thoracotomy. Microvessel density (MVD) as shown by immunostaining of CD34 and proliferative activity with MIB-1 monoclonal antibody was also evaluated. CXCR4 expression (primary, 33.3% positive vs metastatic, 66.6% positive; P ¼ 0.0097) and MVD (primary, 29.8676 ; P ¼ 0.0015) in the metastatic site were both significantly increased compared with those in the primary site, whereas no difference between primary and metastatic sites was observed with regard to VEGF expression. There was a significant positive correlation between immunohistochemical CXCR4 and VEGF expression (P ¼ 0.0269). In total population, the MIB-1-labeling index (LI) was significantly higher in tumors, which showed immunoreactivity for VEGF (MIB-1-LI in VEGF-positive tumors, 24.2975.4 vs VEGF-negative tumors, 18.3374.16; P ¼ 0.034). Furthermore, those patients with VEGFpositive primary tumors had a significantly worse prognosis compared with the patients with VEGF-negative primary tumors (P ¼ 0.0053). Our results suggested that CXCR4 expression was associated with metastatic progression, and immunohistochemical VEGF expression in the primary site had predictive value for the osteosarcoma patients, who developed lung metastasis. It has been demonstrated that certain chemokines can serve as tissue-specific attractant molecules for tumor cells, promoting tumor cell migration to particular sites in vivo. Among chemokines and their receptors, the stromal cell-derived factor-1 (SDF-1/CXCL12)/CXCR4 system has been demonstrated to be involved in the lymph node metastasis or distant metastasis of several types of cancer. [1][2][3][4][5][6][7][8][9][10][11][12] Osteosarcoma is the most frequent primary bone tumor in young adults and adolescents. Despite recent advances in multimodality treatments consisting of adjuvant chemotherapy and surgical-wide resection, pulmonary metastasis occurs in approximately 40-50% of the patients. 13 In such cases, the overall 5-year survival rate is only 28%, despite the multidisciplinary therapy.14 Involvement of the CXCR4/SDF-1 pathway in the metastatic process in the lung has also been demonstrated in osteosarcoma cell lines. 15Immunohistochemical VEGF expression in the untreated primary site has been reported to be correlated with pulmonary metastasis and microvessel density (MVD) in osteosarcoma.16 Wang

Malignant chest wall tumors are classified into eight main diagnostic categories: muscular, vascular, fibrous and fibrohistiocytic, peripheral nerve, osseous and cartilaginous, adipose, hematologic, and cutaneous. However, there are malignant tumors that arise in the chest wall and that do not fit well in any of these categories (eg, Ewing sarcoma and synovial sarcoma). Malignant chest wall tumors typically manifest as painful, rapidly growing, large palpable masses. Chest radiography, the technique most often used for initial evaluation, can be helpful for detecting cortical destruction. However, computed tomography is more sensitive than chest radiography for detecting calcified tumor matrix and cortical destruction. Magnetic resonance imaging often allows more accurate delineation and localization of the tumor and is helpful for determining the presence and extent of tumor invasion and for tissue characterization. Although the imaging features of many malignant chest wall tumors are nonspecific, knowledge of the typical radiologic manifestations of these tumors often enables their differentiation from benign chest wall tumors and occasionally allows a specific diagnosis to be suggested. The article reviews the clinical and imaging features of the most common malignant chest wall tumors and presents images collected at a single cancer referral center.

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