CYTOPATHOLOGY OF FOLLICULAR DENDRITIC CELL TUMORS

Follicular dendritic cell tumors are rarely described entities, arisin g from antigen-presenting immune accessory cells, found within B-lymph ocyte follicles in nodal and extranodal sites. We report two cases, on e associated with Castleman's disease, in whom fine-needle aspiration biopsy was performed followed by surgical biopsy. the diagnosis was co nfirmed using immunoreactivity with CD21 and CD35 antibodies and by ul trastructural demonstration of interdigitating cell processes with des mosomes. Both the cytologic and histologic findings are presented, and the differential diagnoses are discussed. Awareness of this entity an d recognition of the pathologic features may lead to a presumptive dia gnosis which must be confirmed using immunohistochemistry and/or elect ron microscopy. (C) 1997 Wiley-Liss, Inc.