title: Mixed osteoclastic/pleomorphic giant cell tumor of the pancreas: a case report.
abstract: BACKGROUND
  Mixed giant cell tumor (MGCT) of the pancreas is a rare malignant neoplasm. The tumor contains pleomorphic giant cells (PGC), pleomorphic mononuclear cells (PMC) and osteoclastic giant cells (OGC). We describe the first fine needle aspiration biopsy (FNAB) diagnosis of this tumor.
  
  
  METHODS
  A 76-year-old woman was discovered (on imaging studies) to have an apparently inoperable mass in the head of the pancreas. Computed tomography-guided FNAB showed a malignant neoplasm with features of an MGCT. PGC/PMC, OGC and spindle cells were present. The PGC/PMC expressed epithelial antigens, pancytokeratin, CAM 5.2, AE1/AE3 and epithelial membrane antigen (EMA). The spindle cells focally stained for EMA. OGC were negative for the epithelial antigens. OGC, PGC/PMC and the spindle cells were positive for the mesenchymal marker vimentin.
  
  
  CONCLUSIONS
  FNAB was instrumental in making the diagnosis of a rare pancreatic tumor, MGCT. Immunocytochemistry was helpful in making a definitive diagnosis and suggested that MGCT is a carcinosarcoma like neoplasm. The morphology and immunocytochemical profile raise the possibility that osteoclastic giant cell tumor and pleomorphic giant cell tumor may be different morphologic and biologic expressions of the same tumor.
authors.affiliation: Department of Pathology, Saint Louis University School of Medicine, Missouri, USA.
authors.forename: Amobi M
authors.initials: AM
authors.lastname: Ezenekwe
authors.forename: Brian T
authors.initials: BT
authors.lastname: Collins
authors.forename: T Brent
authors.initials: TB
authors.lastname: Ponder
mesh_terms: D000368:Aged; D000954:Antigens, Surface / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000378:metabolism*; D044963:Biopsy, Fine-Needle; D048430:Cell Shape; D003937:Diagnosis, Differential; D005260:Female; D005870:Giant Cell Tumors / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D007633:Keratins / Q000378:metabolism; D008648:Mesoderm / Q000378:metabolism / Q000473:pathology; D018198:Mixed Tumor, Malignant / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology*; D010010:Osteoclasts / Q000378:metabolism / Q000473:pathology*; D010179:Pancreas / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology*; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology*; D014057:Tomography, X-Ray Computed; D014746:Vimentin / Q000378:metabolism
chemical_list: D000954:Antigens, Surface; D014408:Biomarkers, Tumor; D014746:Vimentin; D007633:Keratins