title: Fine needle aspiration cytology in follicular dendritic cell sarcoma: a report of two cases.
abstract: BACKGROUND
  Since the first description of extranodalfollicular dendritic cell sarcoma in 1994, there has been a gradual increase in understanding of the morphologic features and clinical presentation of this tumor. However, difficulties persist in making cytologic diagnosis.
  
  
  METHODS
  Two cases of follicular dendritic cell sarcoma with fine needle aspiration cytology (FNAC) findings were reported. The first patient was a Chinese woman who presented with a right tonsillar mass, which was followed by right submandibular recurrence. The second patient was a Chinese man with known history of Castleman's disease of the nasopharynx complicated by follicular dendritic cell sarcoma, followed by tumor recurrence in cervical lymph nodes. FNAC of both recurrent cases showed isolated or syncytial sheets of tumor cells containing eosinophilic granular cytoplasm, ill-defined cell borders, round to oval nuclei, solitary round eosinophilic nucleoli and fine chromatin.
  
  
  CONCLUSIONS
  The tumor cells in follicular dendritic cell sarcoma show cytologic features reminiscent of native follicular dendritic cells but with a greater than expected cell number and nuclear pleomorphism. These cells may be immunohistochemically inert for follicular dendritic cell markers CD21 and CD35. A presumptive diagnosis on the basis of cytologic examination is possible when paying attention to the subtle morphologic features.
authors: Department of Pathology and Clinical Biochemistry, Queen Mary Hospital, Hong Kong SAR, China. fanyuenshan@hotmail.com
authors: Yuen-Shan
authors: YS
authors: Fan
authors: Wai-Kuen
authors: WK
authors: Ng
authors: Alice
authors: A
authors: Chan
authors: Gavin Shueng-Wai
authors: GS
authors: Chan
authors: Janice
authors: J
authors: Tsang
authors: Chor-Sang
authors: CS
authors: Chim
authors: Philip
authors: P
authors: Ip
mesh_terms: D044963:Biopsy, Fine-Needle; D002467:Cell Nucleus; D020566:Dendritic Cells, Follicular / Q000473:pathology*; D005260:Female; D019337:Hematologic Neoplasms / Q000473:pathology*; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D012509:Sarcoma / Q000473:pathology*; D013363:Submandibular Gland / Q000473:pathology