Follicular Dendritic Cell Sarcoma of the Peripancreatic Lymph Node

Abstract

A 41-mm well-demarcated mass dorsal to the stomach was incidentally found in a 72-year-old Japanese man by abdominal computed tomography. Upper endoscopy showed a tumor protruding outside the stomach and magnetic resonance imaging demonstrated heterogeneous attenuation of the tumor. A gastric gastrointestinal stromal tumor was suspected and laparoscopic tumor resection was performed, which showed that the tumor was isolated from other organs. A follicular dendritic cell sarcoma was diagnosed since the proliferation of oval-to-spindle cells was seen pathologically. In addition, the cells tested positive for the S-100, CD21, CD23, CD35, and follicular dendritic cell markers, but were negative for the cytokeratin, c-kit, CD34, and smooth muscle actin markers on immunological examination. Follicular dendritic cell sarcoma is a rare but malignant tumor, where relapse occurs regardless of excision in 50% of cases. Additional adjuvant chemotherapy is recommended in cases with high-risk features.