Prevotella melaninogenica bloodstream infection in colon cancer combined with appendiceal abscess: A case report

Figure 1 Colonoscopy showed an occupying lesion in the ascending colon. A: Colonoscopy (September 10, 2025): An occupying lesion in the ascending colon causing luminal stenosis; B: Colonoscopic biopsy pathology: Chronic moderate active inflammation of the ascending colon mucosa with focal vascular proliferation and erosion.

Figure 2 Abdominal contrast-enhanced computed tomography (September 8, 2025). Appendiceal abscess with peripheral inflammation; thickened intestinal wall of the ascending colon suggesting tumor or inflammatory lesion.

Figure 3 Abdominal computed tomography findings of appendiceal abscess and secondary small bowel obstruction. A: Abdominal contrast-enhanced computed tomography (November 22, 2025): Enlarged appendiceal abscess after puncture; persistent thickening of the ascending colon wall; B: Abdominal computed tomography (November 25, 2025): Small bowel obstruction caused by the inflammatory mass and abscess.

Figure 4 Gross specimen after right hemicolectomy. Ileocecal tumor with appendiceal abscess and local perforation.

Figure 5 Postoperative histopathology. A: Moderately-poorly differentiated adenocarcinoma of the ascending colon with lymph node metastasis; B: Postoperative pathology: Cancer cell infiltration in the subserosal fibrous tissue of the appendix.