title: [Follicular dendritic cell sarcoma: a clinicopathologic study of five cases].
abstract: OBJECTIVE
  To study the clinical pathological features and immunophenotype of follicular dendritic cell sarcoma (FDCS) with discussion on its diagnostic clues to improve diagnostic level.
  
  
  METHODS
  Five cases of FDCS were analyzed by clinical, pathologic and immunohistochemistry methods.
  
  
  RESULTS
  Five cases of FDCS were located in the cervical lymph node. Microscopically, the normal architectures were effaced by ovoid, spindle-shaped with fascicular, diffuse or whorled patterns and with rich lightly eosinophilic cytoplasm, syncytial appearance. Nuclei tend to show irregular clustering, scattered multinucleated giant cell. Nucleoli often distinct, sometimes prominent. Mitotic count variable, may show significant cellular pleomorphism. Immunohistochemical studies show that the tumor cells were positive for CD21, CD35, but negative for CD1a, CD34, CK and HMB45. Under electron microscopy, the tumor cells possessed long villus cytoplasmic processes and desmosome-like junctions, Birbeck granules were absent.
  
  
  CONCLUSIONS
  FDCS is a rare malignant tumor and differential diagnosis includes Langerhans cell sarcoma, interdigitating dentric cell sarcoma, malignant fibrous histocytoma, melanoma, metastatic spindle cell carcinoma and others. Immunohistochemistry and electron microscopy are necessary for a correct diagnosis.
authors.affiliation: Department of Pathology, Yinzhou People's Hospital, Ningbo 315040, China. zgp123056@sina.com
authors.forename: Guo-ping
authors.initials: GP
authors.lastname: Zhong
authors.forename: Wen-yong
authors.initials: WY
authors.lastname: Sun
authors.forename: Mei-fu
authors.initials: MF
authors.lastname: Gan
authors.forename: Ma-chi
authors.initials: MC
authors.lastname: Yuan
mesh_terms: D000328:Adult; D054740:Dendritic Cell Sarcoma, Follicular / Q000378:metabolism / Q000473:pathology*; D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007150:Immunohistochemistry; D008198:Lymph Nodes / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D017463:Receptors, Complement 3b / Q000378:metabolism; D017464:Receptors, Complement 3d / Q000378:metabolism
chemical_list: D017463:Receptors, Complement 3b; D017464:Receptors, Complement 3d