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.