A retrospective case series of amebic colitis clinical features at a tertiary hospital in Beijing from 2021 to 2024.

BACKGROUND: Amebic colitis, an intestinal infection caused by the parasite Entamoeba histolytica, is increasingly common in nonendemic regions, particularly among young men and men who have sex with men. PURPOSE: This study aims to analyze the clinical manifestations, endoscopic features, pathological characteristics, and treatment outcomes of amebic colitis in male patients diagnosed at a tertiary hospital in Beijing. METHODS: A retrospective analysis was conducted involving 12 male patients aged 28-44 years who were diagnosed with amebic colitis between 2021 and 2024. RESULTS: Clinical evaluation revealed that 83.3% of the patients presented with abdominal pain and/or diarrhea. Endoscopic examination revealed segmental erosions or ulcerations in the ileocecal region, rectum, or entire colon, characterized by irregular ulcers covered with white coating. Histopathological analysis revealed large trophozoites on the inflamed colonic mucosa, with prominent nuclei and evidence of red blood cell phagocytosis in most specimens. Follicular inflammation was identified in 75% of the patients. Coinfections, including human immunodeficiency virus (HIV), latent syphilis and hepatitis C, ulcerative colitis, and a history of anal fistula surgery, were also noted. CONCLUSIONS: Our observed case series may suggest a potentially increasing recognition of amebic colitis in Beijing, though larger population-based studies are needed to confirm true changes in disease prevalence. Colonoscopy plays a critical role in diagnosis by revealing characteristic segmental ulcers in the ileocecal region or rectum. Accurate diagnosis and optimal clinical management require effective collaboration between clinicians and pathologists, supported by specific immunohistochemical staining. CLINICAL TRIAL: This trial was not applicable.