Refractory extra nodal follicular dendritic cell sarcoma in a young male exhibiting a marked response to gemcitabine and docetaxel: A case report and literature review.

Follicular dendritic cell sarcoma (FDCS) is a rare tumour derived from dendritic cells located in B-follicles that play a pivotal role in the adaptive immune response. Surgery is the mainstay of treatment for localized disease; however, the management of unresectable or advanced disease is less well-defined. To date, to the best of our knowledge, there is no established or preferred chemotherapeutic regimen, although a number of regimens (primarily used in lymphomas and sarcomas) have been utilized with suboptimal outcomes. The present study describes the case of a young male patient with advanced-stage unresectable extranodal FDCS that progressed while the patient was undergoing doxorubicin/ifosfamide chemotherapy. Given the limited treatment options available, the patient was subsequently advised to undergo chemotherapy with a combination of gemcitabine/docetaxel. He achieved a marked clinical, as well as radiological response, and an improvement in performance status was also observed. This observation, while having a potential therapeutic bearing, also supports the mesenchymal behaviour of this rare type of tumour. With a number of other recent reports of effective responses to gemcitabine/docetaxel, and an increasing amount of available literature demonstrating its mesenchymal origin, the tumour has been reclassified as 'stroma-derived neoplasms of lymphoid tissues'. Consequently, the accumulation of such case reports can help establish a novel first-line therapeutic regimen for advanced-stage FDCS.