title: Case report: A unique pediatric case of a primary CD8 expressing ALK-1 positive anaplastic large cell lymphoma of skeletal muscle.
abstract: Primary involvement of skeletal muscle is a very rare event in ALK-1 positive anaplastic large cell lymphoma (ALCL). We describe a case of a 10-year old boy presenting with a three week history of pain and a palpable firm swelling at the dorsal aspect of the left thigh. Histological examination of the lesion revealed a tumoral and diffuse polymorphic infiltration of the muscle by large lymphoid cells. Tumor cells displayed eccentric, lobulated "horse shoe" or "kidney-shape" nuclei. The cells showed immunohistochemical positivity for CD30, ALK-1, CD2, CD3, CD7, CD8, and Perforin. Fluorescence in situ hybridization analysis revealed a characteristic rearrangement of the ALK-1 gene in 2p23 leading to the diagnosis of ALK-1 positive ALCL. Chemotherapy according to the ALCL-99-NHL-BFM protocol was initiated and resulted in a complete remission after two cycles. This case illustrates the unusual presentation of a pediatric ALCL in soft tissue with a good response to chemotherapy.
authors.affiliation: Institute of Pathology, Medical Faculty Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany. timo_gaiser@web.de
authors.forename: Timo
authors.initials: T
authors.lastname: Gaiser
authors.forename: Eva
authors.initials: E
authors.lastname: Geissinger
authors.forename: Torsten
authors.initials: T
authors.lastname: Schattenberg
authors.forename: Hanns-Peter
authors.initials: HP
authors.lastname: Scharf
authors.forename: Matthias
authors.initials: M
authors.lastname: Dürken
authors.forename: Dietmar
authors.initials: D
authors.lastname: Dinter
authors.forename: Andreas
authors.initials: A
authors.lastname: Rosenwald
authors.forename: Alexander
authors.initials: A
authors.lastname: Marx
mesh_terms: D030301:Activin Receptors, Type II / Q000378:metabolism*; D016827:CD8 Antigens / Q000378:metabolism*; D002467:Cell Nucleus / Q000473:pathology; D002648:Child; D004358:Drug Therapy; D006801:Humans; D017728:Lymphoma, Large-Cell, Anaplastic / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D008297:Male; D019042:Muscle Neoplasms / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D018482:Muscle, Skeletal / Q000378:metabolism* / Q000473:pathology; D016896:Treatment Outcome
chemical_list: D016827:CD8 Antigens; C425364:ACVRL1 protein, human; D030301:Activin Receptors, Type II