Postoperative liver metastasis of primary inflammatory pseudotumorous follicular dendritic cell sarcoma of the spleen: a case report

Follicular dendritic cell sarcoma (FDCS) is a rare and low incidence tumor. So far, there is no standard treatment for the disease. Surgery is the main treatment for FDCS. Here, we report the case of a 51-year-old woman who was admitted with the chief complaint of "spleen-occupying lesion detected via physical examination more than 1 month ago". Spiral plain scan and enhanced computed tomography (CT) of the upper abdomen showed a vascular-derived tumor, with a high possibility of hemangioma or hemangiolymphangioma. Later, on 25 December 2019, the patient underwent laparoscopic splenectomy, and the pathological diagnosis of primary splenic FDCS was made. The patient did not receive adjuvant chemotherapy or radiotherapy. At a regular follow-up inspection 11 months later, on 18 December 2020, an abdominal scan + enhanced CT revealed multiple new abnormal intrahepatic nodules, which combined with her history, indicated the possibility of metastases. Subsequently, she was readmitted to hospital and surgical treatment was decided upon after multi-disciplinary consultation and discussion. Laparoscopic S1/S3/S4/S5 hepatectomy plus cholecystectomy was performed on 31 December 2020. The postoperative pathology findings revealed (liver tumor, S3, S4, S5) metastatic inflammatory pseudotumor follicular dendritic sarcoma, tumor diameter 0.6-1.2 cm. Due to the lack of clinical reports on postoperative organ metastasis of this disease, less experience, and controversy in drug selection of radiotherapy and chemotherapy, the patient refused to receive radiotherapy and chemotherapy. She now undertakes regular outpatient reexamination, and has been followed-up until now, during which time she has not progressed, and the efficacy is considered satisfactory.