Rhabdomyosarcomas in adults and children: an update.

Department of Pathology, University of Arkansas for Medical Sciences and Arkansas Children's Hospital, Little Rock 72202, USA.
Archives of pathology & laboratory medicine (Impact Factor: 2.88). 11/2006; 130(10):1454-65. DOI: 10.1043/1543-2165(2006)130[1454:RIAACA]2.0.CO;2
Source: PubMed

ABSTRACT Rhabdomyosarcomas comprise a relatively common diagnostic entity among childhood cancers and a relatively rare one among adult tumors. They may possess a variety of histologies that generally differ among age groups. These lesions appear to be separate biologic entities as well as morphologic categories, with embryonal tumors having genetic lesions related to loss of heterozygosity and aberrant parental imprinting, alveolar tumors containing genetic fusions between PAX and forkhead genes, and pleomorphic tumors showing an accumulation of genetic lesions similar to other adult high-grade sarcomas.
To present guidelines for diagnosis of rhabdomyosarcoma and recent finding concerning the biology and classification of these lesions.
Review of recent and older published literature and distillation of the authors' experience.
Infants and young children tend to have embryonal rhabdomyosarcomas, adolescents and young adults tend to have alveolar rhabdomyosarcomas, and older adults tend to have pleomorphic rhabdomyosarcomas, although there is some overlap. Newer rare entities, including spindle cell rhabdomyosarcoma and sclerosing rhabdomyosarcoma, have been described in children and adults. Fusion-positive tumors have a distinct molecular signature with downstream activation of a number of myogenic and tumorigenic factors. Genetic testing may be successfully used for diagnosis and may guide therapy in future clinical trials. Differential diagnosis has become simpler than in previous years, because of use of myogenic factors in immunohistochemistry, but classification based solely on histologic features remains challenging.

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    ABSTRACT: Background:The aim of this study is to understand the epidemiology of tumors in children in our region due to a paucity of studies on the histologic review of the childhood tumors in general and benign tumors in particular.Materials and Methods:The records of all the tumors diagnosed histopathologically in children <14 years of age during a period of 8-year (2005-2012) were reviewed.Results:A total of 385 tumors were seen in the age range of 1 month-14 years with 231 (60%) in boys and 154 (40%) in girls. Highest number of cases, 224 (58.18%) were in the age group of 10-14 years. Benign tumors comprised 275 (71.43%) cases while the malignant tumors accounted for 110 (28.57%) cases. In benign tumors, vascular tumors were in majority with 68 cases, while in malignant category bone tumors were most common with 36 cases.Conclusions:Although the exact incidence rate cannot be provided by this hospital-based study, the information is useful in showing patterns of childhood tumors. We included both benign and malignant tumors, while most of the studies in the past have focused mainly on malignant tumors in children.
    Indian journal of medical and paediatric oncology 04/2014; 35(2):170-4. DOI:10.4103/0971-5851.138995
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    ABSTRACT: Rhabdomyosarcoma is a muscle-derived malignant tumor mainly affecting childhood. The most frequent variant, embryonal rhabdomyosarcoma (ERMS) is characterized by overexpression of the transcription factor, PAX7 which prevents ERMS cells from exiting the cell cycle and terminally differentiating. However, a role for PAX7 in the invasive properties of ERMS cells has not been investigated in detail thus far. Here we show that ectopic expression of RAGE (receptor for advanced glycation end-products) in human ERMS cells results in activation of a RAGE/myogenin axis which downregulates PAX7 by transcriptional and post-translational mechanisms, as in normal myoblasts, and reduces metastasis formation. High PAX7 sustains migration and invasiveness in ERMS cells by upregulating EPHA3 and EFNA1 and downregulating NCAM1 thus favoring its polysialylated form. Microarray gene expression analysis shows that compared with the RAGE(-ve) TE671/WT cells and similarly to primary human myoblasts, TE671/RAGE cells show upregulation of genes involved in muscle differentiation and cell adhesion, and downregulation of cell migration related and MHC class I genes. Our data reveal a link between PAX7 and metastasis occurrence in ERMSs, and support a role for RAGE/myogenin axis in metastasis suppression. Thus, low RAGE expression in ERMS primary tumors may be predictive of metastatic behavior.
    Carcinogenesis 08/2014; DOI:10.1093/carcin/bgu176 · 5.27 Impact Factor
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    ABSTRACT: Spindle cell rhabdomyosarcoma (RMS) is an uncommon histiologic variant of RMS that has spindle cell morphology. This tumor occurs almost exclusively in childhood and more rarely in adults. Only a few adult cases, including two retroperitoneal cases in male patients, have been documented previously. We describe a rare case of spindle cell RMS of the retroperitoneum in a 37-year-old woman developed during pregnancy and incidentally discovered after vaginal delivery. Computed tomography showed a huge tumor mass, measured 20 × 20 × 15 cm in size, arising in retroperitoneal space. Histologically, the tumor consisted of spindle cells arranged in a fascicular or herringbone growth pattern, morphologically mimicking adult fibrosarcoma, intermingled with scattered rhabdomyoblasts. Mitotic activity ranged from 20 to 28 mitoses per 10 high-power fields and tumor necrosis was evident. Immunohistochemically, tumor cells were stained diffusely positive for muscle specific actin, desmin, and vimentin, scattered positive for myogenin, MyoD1 and myoglobin, with a Ki-67 (MIB-1) proliferative labeling index of 46.11%. This tumor also stains positively for CD99, strong cytoplasmic WT1, and nuclear p53. Other markers such as S100 protein, smooth muscle specific actin, CD34, cytokeratin, and epithelial membrane antigen were all negative in the tumor cells. On the basis of the findings, a spindle cell RMS was diagnosed. The neoplasm was incompletely excised because of encasement of major vessels and invasion to adjacent structures, and additional chemotherapy was given.


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