title: Discovered on gastrointestinal stromal tumour 1 (DOG1): a useful immunohistochemical marker for diagnosing chondroblastoma.
abstract: OBJECTIVE
  Cellular areas of chondroblastoma are composed of polygonal chondroblasts with indented nuclei and scattered osteoclast-type multinucleated cells. To learn more about the phenotype of chondroblasts, we investigated the expression of several established immunohistochemical markers in chondroblastomas.
  
  
  RESULTS
  Nine chondroblastomas were analysed using immunohistochemical antibodies [CD34, α-smooth muscle actin (α-SMA), DOG1, CD117, AE1/AE3 and CD163]. Ten chondromyxoid fibromas, seven giant cell tumours of bone and four foetal proximal femurs were also analysed. The cellular areas of each chondroblastoma contained nests of DOG1(+) αSMA(+) CD117(-) CD34(-) chondroblasts, a phenotype that was not detected in chondromyxoid fibroma cases or in giant cell tumours. Although AE1/AE3 was expressed in all chondroblastomas, the staining intensity and proportion of the positive cells varied widely. Intra-lesional CD163(+) macrophages were detected in all cases of chondroblastoma, chondromyxoid fibroma and giant cell tumours.
  
  
  CONCLUSIONS
  Our results demonstrated nests of membranous DOG1(+) chondroblasts located within cellular portions of chondroblastoma containing diffuse heterogeneous infiltrates of mostly DOG1(-) chondroblasts, CD163(+) macrophages and multinucleated osteoclastic giant cells. Thus, chondroblastoma can be added to the tumours that are usually positive for DOG1, alongside gastrointestinal stromal tumour (GIST), rare solid-pseudopapillary neoplasms of the pancreas and exceptional mesenchymal tumours including uterine type retroperitoneal leiomyoma, peritoneal leiomyomatosis and synovial sarcoma.
authors.affiliation: Institute of Pathology, University Medical Centre Hamburg-Eppendorf, Martinistrasse 52, Hamburg, Germany.
authors.forename: Hana
authors.initials: H
authors.lastname: Akpalo
authors.forename: Claudia
authors.initials: C
authors.lastname: Lange
authors.forename: Jozef
authors.initials: J
authors.lastname: Zustin
mesh_terms: D000199:Actins / Q000378:metabolism; D000293:Adolescent; D000328:Adult; D001457:Anion Exchange Protein 1, Erythrocyte / Q000378:metabolism; D000075369:Anoctamin-1; D017920:Antiporters / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001859:Bone Neoplasms / Q000175:diagnosis* / Q000378:metabolism* / Q000473:pathology; D002648:Child; D018118:Chloride Channels / Q000378:metabolism*; D002804:Chondroblastoma / Q000175:diagnosis* / Q000378:metabolism* / Q000473:pathology; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000378:metabolism; D046152:Gastrointestinal Stromal Tumors / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D009363:Neoplasm Proteins / Q000378:metabolism*; D055815:Young Adult
chemical_list: C541116:ACTA2 protein, human; C476213:ANO1 protein, human; D000199:Actins; D001457:Anion Exchange Protein 1, Erythrocyte; D000075369:Anoctamin-1; D017920:Antiporters; D014408:Biomarkers, Tumor; D018118:Chloride Channels; D009363:Neoplasm Proteins; C489237:SLC4A3 protein, human