title: An unusual pathologic feature associated with dermatomyositis.
abstract: We present a case of juvenile dermatomyositis with unusual histopathologic findings. The child presented with a course consistent with dermatomyositis, a diagnosis confirmed by finding reticulotubular aggregates in endothelial cells on electron microscopy. However, histopathology of his muscle biopsy revealed a striking pattern of glycogen accumulation, to an extent similar to that seen in glycogen storage diseases; this degree of accumulation could potentially confound histopathologic diagnosis.
authors.affiliation: Department of Neurology, University of Utah, Salt Lake City, UT, USA. jacinda.sampson@hsc.utah.edu
authors.forename: Jacinda B
authors.initials: JB
authors.lastname: Sampson
authors.forename: Steven S
authors.initials: SS
authors.lastname: Chin
authors.forename: Frederic C
authors.initials: FC
authors.lastname: Clayton
authors.forename: Alan
authors.initials: A
authors.lastname: Pestronk
authors.forename: Kathryn J
authors.initials: KJ
authors.lastname: Swoboda
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Flanigan
mesh_terms: D001706:Biopsy; D002675:Child, Preschool; D003882:Dermatomyositis / Q000175:diagnosis / Q000473:pathology*; D003937:Diagnosis, Differential; D004727:Endothelium / Q000473:pathology / Q000648:ultrastructure; D006003:Glycogen / Q000378:metabolism*; D006008:Glycogen Storage Disease / Q000175:diagnosis / Q000473:pathology; D006651:Histocytochemistry; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000737:chemistry* / Q000473:pathology*; D012154:Reticular Formation / Q000473:pathology / Q000648:ultrastructure
chemical_list: D006003:Glycogen