BACKGROUND: Follicular dendritic cell sarcoma (FDCS) is a rare malignancy of accessory immune cells that can present in both nodal and extranodal sites. Previous cytologic case reports of FDCS have focused on fine needle aspiration (FNA) findings in nodal sites with low grade morphology and indolent clinical courses. CASE: A 33-year-old female presented with a three-month history of abdominal distention, early satiety and nausea. Initial imaging studies showed a large abdominal mass, with subsequent studies showing lung, liver and lymph node metastases. Examination of primary and metastatic tumors by a combination of conventional histology, immunohistochemistry and FNA demonstrated an extranodal intraabdominal follicular dendritic cell sarcoma. CONCLUSION: FDCS demonstrates a characteristic cytologic picture on FNA, with important cytologic features, including both syncytial and discohesive large epithelioid to spindled malignant cells with intranuclear inclusions, nuclear grooves and a prominent, mature, lymphocytic inflammatory component. No evidence of morphologic tumor progression was noted in comparison of primary and metastatic tumors. To aid in the cytologic distinction of FDCS from other similar-appearing neoplasms, we recommend acquisition of material for immunohistochemical studies, recognition of diverse clinical presentations (including extranodal and aggressive) and acknowledgment of the range of tumor morphologic grades.
BACKGROUND:Follicular dendritic cell sarcoma (FDCS) is a rare malignancy of accessory immune cells that can present in both nodal and extranodal sites. Previous cytologic case reports of FDCS have focused on fine needle aspiration (FNA) findings in nodal sites with low grade morphology and indolent clinical courses. CASE: A 33-year-old female presented with a three-month history of abdominal distention, early satiety and nausea. Initial imaging studies showed a large abdominal mass, with subsequent studies showing lung, liver and lymph node metastases. Examination of primary and metastatic tumors by a combination of conventional histology, immunohistochemistry and FNA demonstrated an extranodal intraabdominal follicular dendritic cell sarcoma. CONCLUSION: FDCS demonstrates a characteristic cytologic picture on FNA, with important cytologic features, including both syncytial and discohesive large epithelioid to spindled malignant cells with intranuclear inclusions, nuclear grooves and a prominent, mature, lymphocytic inflammatory component. No evidence of morphologic tumor progression was noted in comparison of primary and metastatic tumors. To aid in the cytologic distinction of FDCS from other similar-appearing neoplasms, we recommend acquisition of material for immunohistochemical studies, recognition of diverse clinical presentations (including extranodal and aggressive) and acknowledgment of the range of tumor morphologic grades.