Entamoeba dispar Liver Abscess Misdiagnosed as Syphilitic Gumma in a People Living With HIV: A Case Report

Entamoeba dispar , a commensal intestinal protozoan indistinguishable from pathogenic Entamoeba histolytica , has traditionally been considered nonpathogenic. Here, we report a rare case of an E. dispar -associated liver abscess in a 38-year-old man with a newly diagnosed HIV infection, initially misdiagnosed as a syphilitic gumma due to concurrent syphilis seropositivity. Despite initial treatment for syphilis, no significant resolution of the abscess was observed. Metagenomic next-generation sequencing of the drainage fluid identified E. dispar , and subsequent treatment with metronidazole resulted in significant radiological improvement. This case highlights the potential pathogenic role of E. dispar in immunocompromised individuals and underscores the importance of mNGS in distinguishing parasitic infections from syphilitic lesions. This case of an E. dispar -associated liver abscess in China illustrates the diagnostic challenges that can arise with such presentations.