title: Sclerosing rhabdomyosarcoma in childhood: case report and review of the literature.
abstract: Rhabdomyosarcoma is the most common soft tissue malignancy in children but is rare in adults. The latest World Health Organization classification of soft tissue tumors recognizes embryonal, alveolar, and pleomorphic rhabdomyosarcomas. More recently, a sclerosing variant of rhabdomyosarcoma has been recognized and reported in seven adult patients. We describe a pediatric case of sclerosing rhabdomyosarcoma presenting as a sacral mass in a 3-year-old girl. Morphologically, the tumor showed a prominent sclerosing hyaline matrix and demonstrated pseudovascular and microalveolar architectural foci. Focal positivity was seen with desmin, smooth muscle actin, and myogenin. MyoD1 showed uniform diffuse nuclear staining. Fusion transcripts were not demonstrated by reverse transcriptase-polymerase chain reaction analysis. The histology, immunohistochemistry, and molecular genetics matched those reported in the seven adult cases of sclerosing rhabdomyosarcoma. This is the first case report, to our knowledge, of this rare tumor arising in the pediatric age group, and we compare the features with those reported in adult sclerosing rhabdomyosarcoma.
authors.affiliation: Department of Histopathology, Camelia Botnar Laboratories, Great Ormond Street Hospital for Children, London WC1N 3JH, UK.
authors.forename: Bhumita
authors.initials: B
authors.lastname: Vadgama
authors.forename: Neil James
authors.initials: NJ
authors.lastname: Sebire
authors.forename: Marian
authors.initials: M
authors.lastname: Malone
authors.forename: Alan Drummond
authors.initials: AD
authors.lastname: Ramsay
mesh_terms: D002675:Child, Preschool; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D017570:MyoD Protein / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012208:Rhabdomyosarcoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D012447:Sacrum / Q000473:pathology*; D012598:Sclerosis / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D012983:Soft Tissue Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*
chemical_list: D017570:MyoD Protein; C057363:MyoD1 myogenic differentiation protein