title: Dysplasia epiphysealis hemimelica: a case report with novel pathophysiologic aspects.
abstract: Dysplasia epiphysealis hemimelica (DEH) is a rare developmental disorder. The underlying pathophysiology is largely unclear. Its diagnosis is based on clinical findings and may be difficult due to its low incidence and close relationship to other disorders such as osteochondroma. We describe a 13-year-old boy who presented with a unilateral lesion of the left medial femoral condyle and left ankle. In addition to standard diagnostic tools such as radiographs and MRI, arthroscopy-guided biopsy was performed; histologic/immunohistochemical findings from cartilage-bone specimens confirmed the diagnosis and provided novel information toward a disease mechanism. The cellular phenotype of clustered chondrocytes exhibited characteristics of chondroprogenitor cells and terminally differentiated cells, suggesting dysregulation of resident progenitor cells. No other surgery was performed and during a 2 year period, we observed spontaneous ossification of the lesion associated with decreased joint impairment. Immunohistochemical analysis of the lesion provided a more accurate diagnosis and may contribute to unraveling potential novel mechanisms involved in its pathogenesis.
authors.affiliation: Department of Orthopaedics, University of Ulm Medical School, Ulm, Germany.
authors.forename: Mario
authors.initials: M
authors.lastname: Perl
authors.forename: Rolf E
authors.initials: RE
authors.lastname: Brenner
authors.forename: Sabine
authors.initials: S
authors.lastname: Lippacher
authors.forename: Manfred
authors.initials: M
authors.lastname: Nelitz
mesh_terms: D000293:Adolescent; D015415:Biomarkers / Q000378:metabolism; D001706:Biopsy; D002358:Cartilage, Articular / Q000378:metabolism / Q000473:pathology*; D019902:Chondrocytes / Q000378:metabolism / Q000473:pathology; D004838:Epiphyses / Q000378:metabolism / Q000473:pathology*; D053823:Hedgehog Proteins / Q000378:metabolism; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000503:physiopathology; D008279:Magnetic Resonance Imaging; D008297:Male; D010009:Osteochondrodysplasias / Q000150:complications / Q000378:metabolism / Q000473:pathology*; D010146:Pain / Q000209:etiology; D044162:Parathyroid Hormone-Related Protein / Q000378:metabolism; D011859:Radiography
chemical_list: D015415:Biomarkers; D053823:Hedgehog Proteins; C509246:IHH protein, human; C470121:PTHLH protein, human; D044162:Parathyroid Hormone-Related Protein