FOLLICULAR DENDRITIC CELL-SARCOMA MIMICKING DIFFUSE LARGE-CELL LYMPHOMA - A CASE-REPORT

Follicular dendritic cell sarcomas (FDCSs) are rare tumors arising fro m follicular dendritic cells in lymphoid tissue. Fewer than 20 cases h ave been described in the English-language literature. We describe the second case of an FDCS with primary liver involvement. The initial di agnosis was lymphoma, and appropriate treatment was prescribed, After the initial treatment failed, additional biopsy samples were obtained, Standard pathologic analysis and immunophenotyping for a panel of mon oclonal antibodies were performed on formalin-fixed paraffin-embedded tissue and frozen sections. The pathologic findings were consistent wi th FDCS, and the specimens showed some of the characteristic pathologi c features suggestive of this tumor, Including multinucleation and a s pindle pleomorphic morphology. The tumor cells were positive for S-100 protein, CD45, CD14, and vimentin. Because of its morphological chara cteristics, FDCS can be confused with other neoplastic entities, such as lymphomas and other solid tumors. (C) 1997 Wiley-Liss, Inc.