1. FOLLICULAR DENDRITIC CELL SARCOMA R4 洪逸平 /VS 顏厥全大夫 財團法人台灣癌症臨床研究發展基金會

2. WHO classification of histiocytic and dendritic-cell neoplasms  Macrophage/histiocytic neoplasm  Histiocytic sarcoma  Dendritic-cell neoplasms  Langerhans cell histiocytosis  Langerhans cell sarcoma  Interdigitating dendritic cell sarcoma/tumor  Follicular dendritic cell sarcoma/tumor  Dendritic cell sarcoma, not otherwise specified

3. Dendritic cell Sarcoma  A rare disease  Divided into interdigitating/follicular dendritic cell sarcoma  IDCS is more invasive  Most of dendritic cell sarcomas (DCS) arise in lymph nodes, about 1/3 involve the extranodal sites

4. Follicular Dendritic cell Sarcoma  Nodal FDCS mostly affected cervical and axillary lymph nodes  Extranodal FDCS mostly affected intra-abdominal organs and involves a wide variety of sites, including spleen, gastrointestinal tract, liver, soft tissue, skin, lung, and breast  Metastatic disease is common in lymph nodes, lung, and liver

5. Epidemiology  80 cases was documented until 2011 in English literature  Onset age is various (9-82), mean age is about 50  Female: male: 1.2:1  Presentation: Painless, slow-growing mass  Lab: anemia and elevated ALP in liver FDC  Tumor is enhanced in PET Hepatobiliary Pancreat Dis Int ， Vol 10 ， No 4 August 15 ， 2011

6. Etiology  FDC express CD21 which is EBV receptor, however the correlation is not well documented  Hyaline-vascular Castleman disease may be a predisposing factor to FDC  p53 pathway may play a role  Epidermal growth factor receptor(EGFR) expression has been investigated

7. Gross Pathology  Solid and tan, may be some hemorrhage or necrosis

8. Histopathology  proliferation of spindle to ovoid cells that form fascicles, storiform patterns, and whorls  Plump, eosinophilic, fibrillary cytoplasm with indistinct cell border

9. CYTOLOGY by FNA

10. Immunohistochemistry  (+): CD21, CD35, and CD23  (-): CD1a, lysozyme, myeloperoxidase, CD34, CD3, CD79a, CD30, HMB-45, and cytokeratins  (+/-)Vimentin, desmoplakin, HLA-DR, CD68, and epithelial membrane antigen  Mostly(-): S100  Others(+): Clusterin, fascin, podoplanin

11. Treatment  Complete surgical resection is the therapy of choice  Adjuvant radiation or chemotherapy showed indeterminate benefit  The optimal combination treatment for FDC sarcoma has yet to be defined  Imatinib may be benefit Onkologie 2007;30:381–384

12. Prognosis  As a low grade sarcoma with high local recurrence rate but low metastasis risk  Overall recurrence: 43%  Overall metastasis: 24%  Overall mortality: 17%  2-year recurrence free survival: 62.3%  5-year recurrence free survival: 27.4%  Poor prognostic factor:  intra-abdominal location,  size ≧ 6 cm,  mitotic count ≧ 5 per 10 high-power fields  coagulative necrosis  Significant nuclear pleomorphism  lack of adjuvant therapy Cancer. 1997;79:294–313. Virchows Arch. 2006;449(2):148–158.

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