title: Expression of desmin and myoglobin in rhabdomyosarcomas and in developing skeletal muscle.
abstract: Immunohistochemical staining for desmin and myoglobin was investigated in 35 rhabdomyosarcomas from young people and in skeletal muscle from 16 human fetuses of known gestational age. Twenty-nine of the rhabdomyosarcomas expressed desmin but six undifferentiated or poorly-differentiated tumours were desmin negative. Of the desmin positive cases, most undifferentiated or poorly-differentiated sarcomas expressed desmin alone (12/35). Tumours with increasing rhabdomyoblastomic differentiation co-expressed myoglobin (9/35) and well-differentiated examples also contained cross-striations (7/35). Skeletal muscle from fetuses aged 8 weeks or less consisted mainly of primitive desmin negative round cells. As the cells began to differentiate they quickly expressed desmin and, at approximately 10 weeks, myoglobin was expressed and cross-striations were seen. The combined results strengthen the view that desmin (within a strictly defined context of round cell tumours in young people) is a reliable marker for rhabdomyoblastic differentiation. Support is also given to the notion that very primitive rhabdomyosarcomas may be desmin-negative, although the difficulties of establishing firm diagnoses for some of these tumours is emphasized.
authors.affiliation: Section of Pathology, Institute of Cancer Research, Surrey, UK.
authors.forename: R L
authors.initials: RL
authors.lastname: Carter
authors.forename: K P
authors.initials: KP
authors.lastname: McCarthy
authors.forename: L G
authors.initials: LG
authors.lastname: Machin
authors.forename: C F
authors.initials: CF
authors.lastname: Jameson
authors.forename: E R
authors.initials: ER
authors.lastname: Philp
authors.forename: C R
authors.initials: CR
authors.lastname: Pinkerton
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D003893:Desmin / Q000378:metabolism*; D005260:Female; D005865:Gestational Age; D006801:Humans; D007223:Infant; D008297:Male; D009132:Muscles / Q000166:cytology / Q000196:embryology / Q000378:metabolism*; D009211:Myoglobin / Q000378:metabolism*; D009373:Neoplasms, Germ Cell and Embryonal / Q000378:metabolism* / Q000473:pathology; D012208:Rhabdomyosarcoma / Q000378:metabolism* / Q000473:pathology
chemical_list: D003893:Desmin; D009211:Myoglobin