Malignant Chest Wall Tumors Part (2)

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1 Malignant Chest Wall Tumors Part (2) Emhmed Saaid,* Mutwakil G. Ahmed,** Mahmoud H. Milad,* Carlo Cireco,* Abstract: Malignant chest wall tumors typically manifest as large, poorly marginated infiltrative masses and are more likely than benign tumors to be symptomatic. Although most malignant tumors have a nonspecific imaging appearance, findings such as chondroid or osteoid matrix, combined fat and soft tissue components or diffuse osteolytic change in association with a soft-tissue rib mass can be helpful in suggesting diagnosis of chondrosarcoma or osteosarcoma, liposarcoma, or multiple myeloma respectively. Changes in benign lesions such as the development of a soft tissue mass in association with preexisting osteochondroma or the loss of a target like appearance in neurofibroma may be early indications of malignant transformation. In some patients, the combined clinical and imaging findings may suggest the diagnosis. For example, findings of chronic lymphedoema may lead to a diagnosis of angiosarcoma, or findings of a large mass with relatively minor rib involvement in a child may indicate a diagnosis of Ewing sarcoma. Even when the findings are nonspecific, imaging is important for tumor staging, therapeutic planning, and follow up of patients with malignant chest wall tumors. However, many chest wall tumors have nonspecific imaging features, and histologic analysis of tissue specimens is frequently required for diagnosis. Even after the decision has been made to perform a biopsy, imaging continues to play an important role in tumor management and is frequently used to facilitate biopsy, assess post procedural complications, and perform follow-up evaluation of tumors that are not excised. Introduction: Malignant chest wall tumors are classified into eight main diagnostic categories: muscular, vascular, fibrous, fibro histiocytic, 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. 1 Malignant chest wall tumors typically manifest as painful, rapidly growing large palpable masses. Chest wall radiography, the technique most often used for initial evaluation, can be helpful for detecting cortical destruction. However, computed tomography (CT) is more sensitive than chest radiography for detecting calcified tumor matrix and cortical destruction. 2 Magnetic resonance imaging (MRI) often allows more accurate delineation and localization of the 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. 3 Chest radiography often is performed at initial evaluation of a clinically suspected malignant chest wall tumor. Although this technique is useful for detecting cortical destruction, a finding indicative of extra-compartmental extension, it does not allow comprehensive assessment of the tumor. 2 Computed tomography (CT) is more sensitive than chest radiography for detecting calcified tumor matrix and cortical destruction. Furthermore, magnetic resonance (MR) imaging, which has a multiplanar capability and often superior spatial resolution, can provide additional information regarding the extent of the tumor, as well as tissue characterization (Table 1, 2). 3,4 *) Department of Radiology, Sebha University, Sebha, Libya. **) Department of Medicine, Sebha University, Sebha, Libya. ***) Department of Radiology, Facalta' Di Medicina E Chirurgia, Italy. 54

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6 Adipose Tissue Tumors Liposarcomas constitute 15% of all sarcomas and usually arise as painless masses in the lower extremities or the retroperitoneum. Chest wall origin is uncommon, occurring in about 10% of cases. The tumor consists of lipoblasts that vary in configuration from poorly differentiated round cells to mature adipose tissue. Many tumors have a large component of myxoid intercellular material. The CT appearance and MR imaging findings are closely correlated with these gross anatomic and microscopic findings. Welldifferentiated tumors have characteristics similar to those of mature fat, whereas poorly differentiated liposarcomas, which are more cellular, have characteristics similar to other solid tumors. The differences seen in these tumors at imaging are reflected in their different prognoses. At CT, the attenuation of liposarcoma is slightly higher than that of normal fat because the tumor contains both fat and soft tissue. The lesions are usually heterogeneous in appearance, reflecting variable cellularity within the tumor. Areas of calcification and ossification may be seen, especially in liposarcomas of the myxoid type. At MR imaging, myxoid liposarcomas usually show moderately high signal intensity on T1- weighted images and high signal intensity on T2-weighted images (Fig. 1). Dedifferentiated liposarcoma should be suspected if a previously well-differentiated liposarcoma develops areas of high signal intensity on T2- weighted images and low signal intensity on T1-weighted images (Fig. 2) and if those areas enhance after intravenous administration of contrast material Figure 1: يجب تعديل رقم الصورة )2 ) Figure 2: 59

7 Malignant lymphoma Primary malignant lymphomas in the chest wall account for less than 2% of soft-tissue tumors, although secondary involvement of the muscle-skeletal system is common in softtissue tumors (Fig. 3) The disease mainly affects patients in their 50s. An increased incidence has been described in individuals who have undergone either orthopaedic surgery with metallic implants or organ transplantation with immune suppressive treatment and in patients with acquired immune deficiency syndrome. CT scans of these lesions show attenuation similar to that of muscle and diffuse slight enhancement after intravenous injection of contrast material. At MR imaging tumors manifest as large masses with intermediate signal intensity equivalent to or slightly lower than that of adjacent muscle on T1-weighted images and with high intensity on T2-weighted images. 15 Infiltration along the neurovascular bundle and extension through the subcutaneous tissues are common. Myeloma Solitary myeloma and multiple myeloma are plasma cell tumors that manifest, respectively, as a single mass or with diffuse marrow involvement. Solitary myeloma is diagnosed in patients at a mean age of about 50 years, in contrast to multiple myeloma, in which the age range at manifestation is years (Fig. 4). 16 Solitary myeloma may progress over time to multiple myeloma. Solitary myeloma of bone, manifests radiologically as a multicystic expansible mass or purely osteolytic focus without expansion. Extra-osseous solitary myeloma, which manifests as a nonspecific soft-tissue mass, progresses less frequently to multiple. 17 Multiple myeloma, the abnormal accumulation of plasma cells in bone narrow, is associated with multiple areas of osteolysis because the plasma cells produce an osteoclast-stimulating factor. Multiple osteolytic lesions with discrete margins are typically detected radiologically in the vertebral column, ribs, or clavicles (Fig. 5). Sclerosis generally develops in the osteolytic lesions after pathologic fracture, irradiation, or chemotherapy but occasionally can be seen also in untreated lesions. At MR imaging, tumors show low signal intensity on T1-weighted images and high signal intensity on T2-weighted images. Contrast enhanced MR imaging may be an effective means of monitoring the response to therapy. 18 Figure 3: 60

8 4a. 5. Figures 4, 5:. (4) Solitary myeloma, in a 69- year-old woman, (a) Nonenhanced CT scan at the level of the pulmonary artery (PS shows a well-defined subpleural mass with reactive bone sclerosis (arrowheads). (b) Photograph of the resected specimen shows a well-demarcated mass (arrows) with minimal bone invasion, (5) Multiple myeloma m a 59- year-old man. Contrast-enhanced CT scan at: the level of the aortic arch (A) shows multiple osteolytic lesions involving the sternum, vertebral body, scapulae, and ribs, and a soft-tissue mass (arrowheads) that originates from a left rib. 4b. Dermato fibrosarcoma Protuberans Dermato fibrosarcoma protuberans is a rare malignant tumor of the skin with a high propensity for local invasion and recurrence. It typically occurs in adolescents but also may occur much later in life. The clinical course is characterized by a strong tendency toward local recurrence of the lesion usually within 3 years after initial treatment. Metastases to the pulmonary and regional lymph nodes have been reported but are rare and usually preceded by multiple local recurrences. Two different types of tumor may occur in this disease: an aggressive fibrosarcomatous variant and a classic variant with a more indolent course. A finding of highgrade fibrosarcomatous change in at least 5% of the lesion indicates the presence of the first variant. 19 CT scans in this type show well-defined nodular subcutaneous lesions with attenuation equal or slightly higher than that of skeletal muscle and with moderate enhancement after intravenous administration of contrast material (Fig. 6-7). MR imaging findings are nonspecific and may include heterogeneous foci of hemorrhage, myxoid change or necrosis

9 Figures 6, 7: (6) Low-grade dermatofibrosarcoma protuberans in 56-year-old man. Contrast-enhanced CT scan at the level of the arch (A) shows a well-demarcated subcutaneous mass (arrow) without muscle invasion, (7) High-grade dermatofibrosarcoma protuberans in 68-year-old woman. Contrastenhanced CT scan at the level of the left atrium (A) shows a large heterogeneous mass (arrow) that originates from the anterior chest wall. Invasion of mediastinal structures (arrowheads) suggests malignancy. Ewing Sarcoma A clinic-pathologic entity characterized by malignant small cell tumors that appeared to originate in the soft tissue of the chest wall or the periphery of the lung was first described by Askin et al 21 in 20 children and adolescents. Then known as primitive neuroectodermal tumor, this lesion is now recognized as an aggressive type of Ewing sarcoma. Both tumor types manifest most often in children and young adults and probably develop from embryonal neural crest cells. Both also contain the same balanced reciprocal translocation between chromosomes 11 and 22. The translocation point has been cloned and is identical in the two tumor types Ewing sarcoma of the chest wall develops either as a solitary mass or as multiple masses with an eccentric growth pattern. Tumors usually occur in the ribs, scapula, clavicle, or sternum but occasionally have an extra-skeletal site of origin. Expansion of a chest wall tumor may cause the lung to collapse, or the neoplasm may invade the lung. Ewing sarcoma often originates in a paravertebral region and extends through the vertebral foramina. Although tumors generally tend to displace adjacent soft-tissue structures rather than invade or encase them, large tumors may or may not be accompanied by calcification. 24 On T-weighted MR images, tumors generally have signal intensity equal to or greater than that of muscle. Larger tumors appear as heterogeneous masses, frequently with evidence of hemorrhage or necrosis (Fig. 8). Whereas smaller ones tend to be more homogeneous. On T2-Weighted images the tumors tend to have heterogeneous high signal intensity. Tumors show marked enhancement after intravenous administration of contrast material

10 Figure 8: Synovial Sarcoma Synovial sarcomas are rare malignant mesenchymal neoplasms that most often occur near joint capsules, bursae, and tendon sheaths of the extremities. Synovial sarcoma in the chest wall is extremely rare and usually occurs in patients of ages years but may also occur later in life. Synovial sarcoma is clinically and morphologically well-defined and has been extensively described in the literature; however, its biologic feature remains controversial. Specific diagnosis is made by identifying a t(x;18)(p11;q11) translocation in the tumor cells. 26 CT scans typically show a soft-tissue mass with attenuation slightly higher than that of muscle and may show infiltration of adjacent structures. Cortical bone erosion or invasion is well depicted at CT, as are intratumoral calcification, which are noted in 20-30% of cases. 27 On T1-weighted MR images, most tumors show heterogeneous signal intensity that is predominantly equivalent to that of muscle. Small foci of high signal intensity on T1- weighted images, which are present in 45% of cases, indicate hemorrhage. Fluid-fluid levels can be striking and are seen in 15-25% of patients. 28 Findings of hemorrhage and fluid-fluid levels or high signal intensity on any MR image may be associated with a worse prognosis, because these tumors are usually large and extensively invasive of surrounding tissue. On T2-weighted images, marked heterogeneity is the rule, and various degrees of internal septation may be noted (Fig. 9). These findings are especially characteristic of large tumors, 85% of which have heterogeneous signal intensity A combination of three different signal intensity levels is present on T2-weighted images in 33% of cases. This triple-signal intensity pattern on T2- weighted images, when accompanied by small foci of high signal intensity on T-weighted images, calcification, and proximity to a joint, may indicate the diagnosis. 63

11 Figure 9: Proximal-type Epitheloid Sarcoma Proximal-type epithelied sarcoma is a distinctive neoplasm that commonly involves soft tissue in the extremities. Although it may occur at any age, the tumor is most often found in adolescents and young adults. Lesions may be subcutaneous or deep seated and usually are attached to tendons, tendon sheaths, or fascial structures. 30 On CT scans, ossification or stippled calcification is observed in 20-30% of cases. On T1-weighted MR images, the tumor has the same signal intensity as muscle and may be visible only because of its mass effect. On T2- weighted MR images, the tumor shows heterogeneous high signal intensity. Heterogeneous strong enhancement is observed after the administration of contrast material (Fig. 10). 31 Figure 10: Acknowledgement: This research was sponsored by the Libyan government. 64

12 References: 1. Athanassiadi K, Kalavrouzistis G, Randogianni D, et al. Primary chest wall tumors: early and long-term results of surgical treatment. Eur J Cardiothorac Surg, 2001; 19: Jeung M, Gangi A, Gasser B, et al. Imaging of chest wall disorders. Radiographic. 1999; 19: Siegel MJ. Magnetic resonance imaging of musculoskeletal soft tissue masses. Radiol Clin North Am, 2001; 39: McClain K, Leach CT, Jenson HB, et al. Association of Epstein-Barr virus with leiomyosarcomas in children with AIDS. N Engl J, 1995; 332: Arkun R, Meiss A, Akalin T, et al. Liposarcoma of soft tissue: MRI findings with pathologic correlations. Skeletal. Radiol. 1997; 26: Henricks WH, Chu YC, Goldblum JR, et al. Dedifferentiated liposarcoma: a clinico pathologic analysis of 155 cases with a proposal for an expanded definition of dedifferentiation. Am J Surg Pathol. 1997; 21: Ippolito V, Brion E, Menendez L, et al. Case report: "De differentiated": lipoma-like liposarcoma of soft tissue with focal transformation to high-grade "sclerosing" osteosarcoma. Skeletal Radiol. 1993; 22: Jelinek JS, Kransdorf MJ, Shnooler BM, et al. Liposarcoma of the extremities: MRI and CT findings in the histologic subtypes. Radiology. 1993; 186: Kransdorf MJ, Meis JM, Jelinek JS. Dedifferentiated liposarcoma of the extremities: imaging findings in four patients. AJR Am J Roentgenol. 1993; 161: London J, Kiss EE, Wallace S, et al. MR imaging of liposarcoma: correlation of MRI feature and histology. J Compat Assist Tomogr. 1989; 13: Munk PL, Lee MJ, Janzen DL, et al. Lipoma and liposarcoma: evaluation using CT and MR imaging. AJR Am J Roentgenol. 1997; 169: Sundaram M, Bran G, Merenda G, et al. Myxoid liposarcoma: magnetic resonance imaging appearance with clinical and histological correlation. Skeletal Radiol. 1990; 19: Jaffe ES. Anaplastic large cell lymphoma: the shifting sands of diagnostic hematopathology. Mod Pathol. 2001; 14: Lee US, Martinez S, Coleman RE. Primary muscle lymphoma: clinical and imaging findings. Radiology. 1997; 203: Malloy PC, Fishman EK, Magid D. Lymphoma of bone, muscle, and skin: CT findings. AJR Am J Roentgenol. 1992; 159: Bataille R, Sany J. Solitary Myeloma: clinical and prognostic features of a review of 114 cases. Cancer. 1981; 48: Corwin J, Lindberg RD. Solitary plasmacytoma of bone vs extra plasmacytoma and their relationship to multiple myeloma. Cancer. 1979; 43: Libshitz HI, Malthouse SR, Cunningham D, et al. Multiple myetoma: appearance of MR Imaging. Radiology. 1992; 182: Diedhiou A, Larsimont D, Vandeweyer E, et al. Fibrosarcomatous variant of dermatofibrosarcoma protuberans: clinical and pathologic analysis of 4 cases. Ann Pathol. 2001; 21: Kransdorf MJ, Maiskmdblom JM. Dermato-fibrosarcoma protuberans: radiologic appearance. AJR Am Roentgenol. 1994; 163: Askin FB, Rosai J, Sibley RK, et al. Malignant small cell tumor of the thoracopulmonary region in childhood: a distinctive clinico pathologic entity of uncertain histogenesis. Cancer. 1979; 43: Dehner LP. Primitive neuroectodomal tumor and Ewings sarcoma. Am J Surg Pathol. 1993; 17: Ladanyl M, Heineman F, Huvos A, et al. Neural differentiation in small round cell tumors of bone and soft tissue with the translocation t(11;22)( 24; 12): an immunohistochemical study of 11 cases. Human Pathol. 1990; 21: Winer-Muram HT, Kauffman WM, Gronemeyer SA, et al. Primitive neuroectodermal tumor of the chest wall: CT and MR findings. AJR Am J Roentgenol. 1993; 161: Boyko OB, Cary DA, Cohen MD, et al. MR imaging of osteogenic and Ewing's sarcoma. AJA Am J Roentgenol. 1987; 148:

13 26. Turc-Carel C, Dal Cin P, Limon J, et al. Translocation X;18 in synovoid sarcoma. Cancer Genet Cytogenet. 1986; 23: Sanchez-Reyes JM, Alcaraz M, Quinone D, et al. Extensively calcified synovial sarcoma. Radiol. 1997; 26: Jones BC, Sundaram M, Kransdorf MJ, Synovial Jarcoma: MR imaging findings in 34 patients. AJR Am J Roentgenol. 1993; 161: Marlon MJ, Berquist TH, McLeod RA, et al. MR imaging of synovial sarcoma. AJR Am Roentgenol. 1991; 156: Hazegowa T, Matsonu Y, Shimoda T, et al. Proximal-type epitheloid sarcoma: a clinicopathological study of 20 cases. Mod Pathol. 2001; 14: Tateshi U, Hasegawa T, Kusumob M, et al. Radiologic manifestations of proximal-type epitheloid sarcoma of the soft tissue. AJR Am J Roentgenol. 2002: 179: