We present the case of a patient with abdominal follicular dendritic cell sarcoma (FDCS) with liver metastasis, a tumor with an extremely low prevalence. The preoperative diagnosis of FDCS remains challenging due to the rarity of this disease. Despite the complete surgical removal of the lesion, the risk of local recurrence after surgery for FDCS remains high. Furthermore, adjuvant radiotherapy and chemotherapy have been demonstrated to have no significant impact on the overall survival of the patient. A pan-cancer panoramic gene test was conducted on pathological specimens from patients, and the results indicated the presence of a class II variant, namely a reduction in the copy number of the CDKN2A gene. Piperacillin may prove to be a targeted drug with the potential to influence patient prognosis. During the three-month follow-up period following asymptomatic discharge, the patient's condition remained stable. The genetic testing of surgical resection specimens to determine subsequent treatment plans may represent a future treatment strategy.Copyright © 2025. Published by Elsevier Masson SAS.