Soft Tissue Tumor

Abstract Abstract Abstract Gardner's syndrome is an autosomal dominant disease characterized by the presence of colonic polyposis, osteomas and a multitude of soft tissue tumors. The syndrome may present at any age from 2 mo to 70 years with a variety of symptoms, either colonic or extracolonic. We present a case of a 11-year-old female patient with Gardner's syndrome

Flat-panel volume computed tomography (fpVCT) is a recent development in imaging. We discuss some of the musculoskeletal applications of a high-resolution flat-panel CT scanner. FpVCT has four main advantages over conventional multidetector computed tomography (MDCT): high-resolution imaging; volumetric coverage; dynamic imaging; omni-scanning. The overall effective dose of fpVCT is comparable to that of MDCT scanning. Although current fpVCT technology has higher spatial resolution, its contrast resolution is slightly lower than that of MDCT (5-10HU vs. 1-3HU respectively). We discuss the efficacy and potential utility of fpVCT in various applications related to musculoskeletal radiology and review some novel applications for pediatric bones, soft tissues, tumor perfusion, and imaging of tissue-engineered bone growth. We further discuss high-resolution CT and omni-scanning (combines fluoroscopic and tomographic imaging).

Background Liposarcoma is the most common primary retroperitoneal malignant neoplasm. However, preoperative diagnosis is a common problem due to lack of characteristic clinical presentations. It has been assumed that MRI, based on its high soft-tissue resolution, could discover and discern different subtypes of this tumor. Moreover, there has been little in the literature to compare the MRI features with pathological appearances of the retroperitoneal liposarcomas. Methods We retrospectively analyzed 19 cases of retroperitoneal liposarcoma (11 males and 8 females, aged 41–79 years) proved surgically and histologically. All patients underwent MRI examination before and after the administration of contrast agent. The MRI features and postoperative pathological appearances were studied correlatively. Results Nine cases were located in the anterior pararenal space, four cases in the posterior pararenal space and six cases in the perirenal space. Among all cases, ten cases were present in the right retroperitoneum and nine cases in the left. The average diameter of the tumors was 14.7 cm (range from 7.5 cm to 26 cm). The MR signal intensity of liposarcoma was heterogeneous and varied greatly, depending on the components of the tumor and the different histological patterns. There are five subtypes of retroperitoneal liposarcoma. Myxoid liposarcoma (n = 7) exhibited low signal intensity on T1W image and high signal intensity on T2W image. On histologic analysis, myxoid liposarcoma consists of a myxoid matrix as the predominant component and small amounts of mature fat. Enhanced solid tissues and thickened septa of myxoid liposarcoma were seen on post-contrast image. Well-differentiated liposarcoma (n = 5) presented in high signal intensity on T1W images, intermediate signal intensity on T2W images, drop-out signal intensity on fat-suppressed MR images; The enhanced tenuous septa and solid tissues were seen on post-contrast image. Round-cell liposarcoma (n = 2) and pleomorphic liposarcoma (n = 2) exhibited soft-tissue tumor signal intensity without characteristic fat signal. One case of round-cell liposarcoma appeared with intratumoral hemorrhage and invaded the inferior vena cava. Dedifferentiated liposarcoma (n = 3) exhibited small amounts of fatty components with a clear demarcation between fat and nonadipose solid tissue on MR images. One case of dedifferentiated liposarcoma invaded the kidney. Conclusion MRI can clearly demonstrate shape, margin, internal components and surrounding tissues. Different subtypes of retroperitoneal liposarcoma exhibited varying MRI features, depending on tumor histological components. MRI should be an ideal method for diagnosing retroperitoneal liposarcoma.

Most bladder tumors arise from the urothelium. However, there are several uncommon but significant bladder lesions that must be differentiated from urothelial carcinomas. These include both benign and malignant spindle cell lesions. The first half of this 2-part review will describe benign myofibroblastic proliferations including inflammatory myofibroblastic tumor and postoperative spindle cell nodule; benign neoplasms including leiomyoma, hemangioma, neurofibroma, and schwannoma; and tumors of uncertain malignant potential including paraganglioma, granular cell tumor, and perivascular epithelioid cell tumor. Common clinical presentations, morphological characteristics, and immunohistochemical features are described to aid the practicing pathologist in the identification of these entities. This review also describes current theories as to the pathogenesis of inflammatory myofibroblastic tumor and postoperative spindle cell nodule and details the current molecular markers identifying...

SUMMARY Extragastrointestinal stromal tumors (EGISTs) are rare type of soft tissue tumors in peritoneal cavities and retroperitoneal region. Because of histologic Predictors may lead some confusion, immunohistochemical techniques are valid both in diagnosis and differential diagnosis. In this report, we present an EGIST which insidentally was found during laparotomy due to rectal adenocarcinoma in 74 years old male patient. EGISTs clinical, histopathological and immunohistochemical features are discussed in view of the literature.

A rhabdomyoblastic differentiation in a malignant peripheral nerve sheath tumor is unusual and is termed as a malignant triton tumor. A series of 10 such cases with their clinicomorphological features, diagnosed over a 10-year period, is presented. The average age of occurrence was 30 years, with the maximum number of cases in the second decade and with male outnumbering female

Malignant ectomesenchymoma is a rare soft tissue tumor of childhood composed of both mesenchymal and neuroectodermal elements. Reported sites of origin are head and neck, abdomen, perineum, scrotum, and extremities. A new case of an orbital ectomesenchymoma in a 7-year-old boy is presented. The clinical picture of the tumor, radiological findings, and its histopathologic and immunohistochemical characteristics are described. The

Histologic grading has been considered the most important prognostic factor for soft tissue sarcomas. Several grading systems have been proposed based on the assessment of morphologic features in heterogeneous groups of sarcomas. Currently, the French Federation of Cancer Centers (FNCLCC) and the National Cancer Institute (NCI) grading systems are the most commonly used. These systems are based on a few morphologic predictors of biologic behavior, which is justifiable because of the rarity of soft tissue sarcomas. Nonetheless, over- or underestimation of prognosis may occur because of an uneven representation of specific sarcomas with rather distinct biologic behaviors among studies of grading systems. In addition, lack of standardization of morphologic criteria and frequent omission of the influence of clinical factors on the final survival analyses preclude universal acceptance of a particular grading system. New advances in diagnostic imaging, quantitative morphometric technologies, cytogenetics, and molecular genetics, allied with alternative analytic data systems, may provide better validation, reproducibility, and prognostic capabilities for current and future grading systems. This article summarizes and critically analyzes the various important grading systems that have thus far been proposed and suggests alternatives for the elaboration of more reproducible systems with higher predictive capabilities.