Abstract

Follicular dendritic cell (FDC) sarcoma is a neoplastic proliferation of FDCs. Because its cytologic findings can vary widely, both the cytomorphology and histopathology of FDC sarcoma can impose a significant diagnostic dilemma. We present cytologic features of FDC sarcoma assessed by intraoperative touch imprint. Intra-abdominal lymphadenopathies were noted in 54-year-old male with hepatitis B-virus associated liver cirrhosis. In contrast to cytologic features of classical FDC sarcoma, the tumor cells featured a large epithelioid or Reed-Sternberg cell-like shape scattered in a background with abundant inflammatory cells, which led to a mistaken diagnosis of malignant lymphoma. However, in accordance with cytologic features previously described in the literature, the tumor cells were characterized by a fragile cytoplasm with cytoplasmic processes in dendritic or reticulated patterns reminiscent of the ultrastructural features of FDC. Cytoplasmic features rendering nuclei with a tendency to form clusters or syncytial aggregates associated with reactive lymphocytes appear to be the most valuable finding in diagnosis of FDC sarcoma.

• Keywords: Dendritic cell;Follicular;Sarcoma;Cytology;Lymph nodes