title: [Rhabdomyosarcoma: morphology and cellular differentiation].
abstract: 544 malignant soft tissue tumors have been collected at the Pediatric Tumor Registry in Kiel including 300 cases of rhabdomyosarcoma (55%). In 237 of the 300 cases the diagnosis is certain. Liposarcoma and malignant fibrous histiocytoma which are typical tumors of adult age are rare in our material. Among rhabdomyosarcomas embryonal rhabdomyosarcoma (eRMS) clearly predominates accounting for almost 72% of all rhabdomyosarcomas. Differentiation of tumor cells in eRMS may vary considerably. Therefore, three groups of eRMS were distinguished and analyzed for clinico-pathologic features: 1. Primitive eRMS with less than 10 rhabdomyoblasts. 2. Intermediate eRMS with 10-50% rhabdomyoblasts. 3. Well differentiated eRMS with greater than 50% rhabdomyoblasts. By immunohistochemistry, vimentin positive cells were found in all three groups. The number of desmin positive cells depended upon the grade of differentiation. Thus, there were more desmin positive cells in well differentiated eRMS. Primitive and well differentiated eRMS were predominantly located in the head and neck area, intermediate eRMS in the abdomen. Primitive eRMS were noted in higher stages than tumors of the other two groups. Response to chemotherapy as evaluated in the 7th week of treatment was better in well differentiated eRMS. Moreover, patients of this group achieved more often complete remission. It is concluded from the present study that differentiation in eRMS may have an influence on the clinical presentation and clinical course of the disease. Therefore, this question should be investigated in more detail in a larger prospective study.
mesh_terms: D000008:Abdominal Neoplasms / Q000473:pathology; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D002454:Cell Differentiation / Q000187:drug effects; D002471:Cell Transformation, Neoplastic / Q000473:pathology; D002648:Child; D003893:Desmin / Q000378:metabolism; D003937:Diagnosis, Differential; D006258:Head and Neck Neoplasms / Q000473:pathology; D006801:Humans; D007124:Immunoenzyme Techniques; D009211:Myoglobin / Q000378:metabolism; D009367:Neoplasm Staging; D011379:Prognosis; D012208:Rhabdomyosarcoma / Q000188:drug therapy / Q000473:pathology*; D012983:Soft Tissue Neoplasms / Q000188:drug therapy / Q000473:pathology*; D014746:Vimentin / Q000378:metabolism
chemical_list: D003893:Desmin; D009211:Myoglobin; D014746:Vimentin
vernacular_title: Rhabdomyosarkom: Morphologie und zelluläre Differenzierung.