Follicular Dendritic Cell Sarcoma

This is a case of a follicular dendritic cell sarcoma. This rare tumor recapitulates the morphology and immunophenotypic profile of normal follicular dendritic cells. Up to 20% of cases are associated with Castleman's disease.

Immunohistochemical studies are essential for making the diagnosis. Tumor cells are positive for CD21, CD23, CD35 , clusterin, HLA-DR, fascin, EGFR, and vimentin. Ki-67 can be positive in up to 25% of tumor cells.

Click images to begin the slideshow

Slide 1: 52 year old woman with a history of Castleman's disease presenting with a 5 cm abdominal wall mass.<br><br>Low power examination reveals a multinodular tumoral growth involving fibroadipose tissue.

Slide 2: TThe tumor shows storiform and whorled bundles of spindle cells surrounded and focally infiltrated by lymphocytes.

Slide 3: The neoplastic spindled cells are highly uniform and the intermixed blood vessels are typically surrounded by a cuff of small lymphocytes.

Slide 4: The tumor cell nuclei range from vesicular to having fine granular chromatin. Nucleoli are present but not conspicuous. The cytoplasm is eosinophilic and moderate in amount. Small lymphocytes are present infiltrating between the tumor cells. Mitotic activity was very focal and did not exceed 2/10 high power fields.