Extranodal follicular dendritic cell sarcomas: Inflammatory Pseudotumor-like variant with increased frequency of a concurrent secondary cancer
1
Department of Pathology, Miaoli General Hospital, Miao-li, Taiwan, Taiwan
2
Department of Surgery, Miaoli General Hospital, Miao-li, Taiwan, Taiwan
3
Department of Pathology, Tungs' Taichung MetroHarbor Hospital, Taichung, Taiwan
4
Department of Surgery, Far Eastern Memorial Hospital, New Taipei City, Taiwan
5
Department of Pathology, Chi Mei Medical Center, Tainan, Taiwan
Abstract
OBJECTIVE: To analyze the clinicopathological features of extranodal follicular dendritic cell (FDC) sarcomas in Taiwan. STUDY DESIGN: Extranodal FDC sarcoma is rare and can be classified into either conventional type or inflammatory pseudotumor (IPT)-like variant. Nearly all gastrointestinal FDC tumors are of the conventional type and Epstein-Barr virus (EBV) unrelated, while the IPT-like variant occurs almost exclusively in the liver and spleen and is consistently associated with EBV. We report 3 new cases of extranodal FDC sarcoma in Taiwan and review their features along with 3 previously published cases. RESULTS: The cases included 2 males and 4 females with a median age of 73 (range, 37-78). Two cases were of the conventional type, and 4, IPT-like variant. Immunohistochemically, all tumors except 1 case expressed at least 1 FDC marker. EBV was detected in 3 of the 4 cases of IPT-like variant by in situ hybridization. The single case with EBV-negative IPT-like variant was considered to be secondary hepatic involvement by an omental/ mesenteric FDC sarcoma. Two patients had concurrent cancers in other organs. The clinical course was indolent in most cases after operation, although follow-up was either unavailable or short in some patients. CONCLUSION: We found that FDC sarcomas in Taiwan occur more commonly in elder females, are frequently of the IPT-like variant, with an indolent course, and with a high proportion of patients having a concurrent cancer in a second organ. © Science Printers and Publishers, Inc.