Clinicopathological analysis of Epstein-Barr virus-positive imflammatory follicular dendritic cell sarcoma

HUANG Lei; HE Hui-hua; AO Qi-lin; YUAN Jing-ping; KE Xiao-kang

doi:10.3969/j.issn.1007-8096.2025.05.011

Abstract：Objective To explore the clinical pathological features of Epstein-Barr virus-positive imflammatory follicular dendritic cell sarcoma(EBV+IFDCS),and share our experience in diagnosing this tumor.Methods The clinical manifestations,pathological features,immunophenotypic characteristics,EBV-encoded mRNA(EBER)in-situ hybridisation,gene rearrangement,diagnosis and differential diagnosis of 5 cases of EBV+IFDCS were retrospectively reviewed,and related literatures were reviewed.Results Among the 5 patients,there were 2 males and 3 females.The age ranged from 48 to 67 years,with a median age of 53 years.Most of the clinical findings were space-occupying lesions of spleen or colon during routine physical examination or due to chest and back pain,abdominal pain and other symptoms(2 cases in spleen and 3 cases in colon).On microscopic observation,the normal structure of the tissue was partially destroyed,scanty atypical ovoid to spindle neoplastic cells with ill-defined cell borders were dispersed in a background of florid lymphoplasmacytic infiltrate.The neoplastic cells were formed loose whorled fascicles.They had vesicular nuclei with distinct nucleoli.Scattered epithelioid granuloma was seen in the background of 1 case,and eosinophils were abundant in the background of 1 case.Immunohistochemistry demonstrated that the neoplastic cells showed variable expression of follicular dendritic cell markers like CD21,CD23,CD35 and D2-40.Tumor cells were positive for EBER in all 5 cases.For two of the cases,immunoglobulin(Ig)/T cell receptor(TCR)gene rearrangement detection was performed with both results being negative.All patients underwent surgical treatments such as endoscopic submucosal resection of colonic polyps or colectomy.After 1 to 62 months of follow-up,all patients were tumor-free survivors.Conclusions EBV+IFDCS is an extremely rare tumor with a unique morphological and immunophenotype.Therefore,accurate identification of it is very important,which helps to improve the diagnostic rate and prevent misdiagnosis and mistreatment.