A Rare Aggressive Case of Follicular Dendritic Cell Sarcoma

Follicular dendritic cell sarcoma (FDCS) is a rare lymphoid neoplasm with indolent clinical process. However, we presented here a rare case of FDCS in aggressive pace.

The case was a 48-year-old female complaining of dysphagia for half a year. She was found gastric fundus bulge under gastroscopy and diagnosed as low-differentiated gastric adenocarcinoma in the local hospital. After three courses of chemotherapy with paclitaxel combined with oxaliplatin and 5-fluorouracil, PET-CT showed progressive disease (PD) with not only gastric bulk but also invasion to the liver and multiple lymph nodes in the abdomen. The patient was admitted to the Department of Surgery of our hospital. Total gastrectomy and liver tumor resection were performed and postoperative pathology demonstrated FDCS. The patient was transferred to our department for chemotherapy. After three courses of CHOP, PET-CT showed tumor in the anastomotic site, partial liver resection margin and left adrenal gland. The patient was sent for radiotherapy. After radiation, PET-CT demonstrated PD and the puncture of left supraclavicular lymph node confirmed FDCs. Thalidomide and prednisone were given orally. At the same time, the whole exome sequencing (WES) was performed, based on which therapy response index (TRI) was analyzed by Cellworks software. According to TRI, the regimen of etoposide, carboplatin, bendamustine and chidamide was chosen for the patient. After the chemotherapy, the patient developed repeated vomiting and diarrhea. Abdominal CT showed intussusception and intestinal obstruction. She was sent for gastrointestinal surgery to relieve obstruction and postoperative pathology again confirmed FDCS. However, her abdominal pain and diarrhea occurred again one month after operation. The patient was discharged voluntarily and went to local hospital for supportive care.

During a year from the onset to abandon of tumor therapy, the case was administered operation, radiotherapy and chemotherapy. The regimens of chemotherapy included paclitaxel-based chemotherapy for solid tumors, CHOP for lymphoma, and formulated regimen according to the analysis of WES. However, all of these therapeutic strategies were unable to control the progress of her disease. Hitherto, there is no guideline or consensus to guide the treatment of FDCS. The diagnosis and treatment process of this relapsed and refractory case can provide reference for clinicians to manage FDCS.