Follicular dendritic cell (FDC) is an essential component of the nonlymphoid, nonphagocytic immunoaccessory reticulum cells of the peripheral lymphoid tissue(1). FDCs are confined largely to the primary and secondary ...Follicular dendritic cell (FDC) is an essential component of the nonlymphoid, nonphagocytic immunoaccessory reticulum cells of the peripheral lymphoid tissue(1). FDCs are confined largely to the primary and secondary B-cell follicles, where they form a tight interlacing meshwork. They play a role in the capture and presentation of antigens, generation and regulation of immune complexes. FDCs can be recognized morphologically by their indistinct cellular borders, pale eosinophilic cytoplasm, round-to-ovoid nuclei with delicate nuclear membranes and clear-to-vesicular chromatin with inconspicuous or small nucleoli. FDCs are best identified through immunostaining using CD21, CD35, R4/23, KiM4, KiM4p and Ki-FDC1p. A proliferation of FDCs may be seen in a variety of lesions, including reactive follicular. hyperplasia, Castleman's disease, follicular lymphoma, mantle cell lymphoma, angioimmunoblastic T-cell lymphoma and nodular lymphocyte predominant Hodgkin's lymphoma. Previous studies(2-5) showed that follicular dendritic cell sarcoma (FDCS) affected predominantly the lymph nodes, with occasional extranodal involvement. As the tumor consists mainly ovoid-to-spindle cells, it is not uncommon to misdiagnose the lesion as a wide variety of other spindle cell sarcomas. This study focused on characterizing the histologic features of extranodal FDCS to promote the recognition of this rare entity for both clinicians and pathologists.展开更多
文摘Follicular dendritic cell (FDC) is an essential component of the nonlymphoid, nonphagocytic immunoaccessory reticulum cells of the peripheral lymphoid tissue(1). FDCs are confined largely to the primary and secondary B-cell follicles, where they form a tight interlacing meshwork. They play a role in the capture and presentation of antigens, generation and regulation of immune complexes. FDCs can be recognized morphologically by their indistinct cellular borders, pale eosinophilic cytoplasm, round-to-ovoid nuclei with delicate nuclear membranes and clear-to-vesicular chromatin with inconspicuous or small nucleoli. FDCs are best identified through immunostaining using CD21, CD35, R4/23, KiM4, KiM4p and Ki-FDC1p. A proliferation of FDCs may be seen in a variety of lesions, including reactive follicular. hyperplasia, Castleman's disease, follicular lymphoma, mantle cell lymphoma, angioimmunoblastic T-cell lymphoma and nodular lymphocyte predominant Hodgkin's lymphoma. Previous studies(2-5) showed that follicular dendritic cell sarcoma (FDCS) affected predominantly the lymph nodes, with occasional extranodal involvement. As the tumor consists mainly ovoid-to-spindle cells, it is not uncommon to misdiagnose the lesion as a wide variety of other spindle cell sarcomas. This study focused on characterizing the histologic features of extranodal FDCS to promote the recognition of this rare entity for both clinicians and pathologists.
