S4076 Unexpected Cytomegalovirus Inclusions in Inflammatory Colonic Polyp in a Non-Immunocompromised Patient: A Case Report

Introduction: Cytomegalovirus (CMV) is a double-stranded DNA herpes virus infecting 50%–80% of US adults by age 40. Most infections are mild or asymptomatic. In immunocompromised patients, it can cause disseminated or localized end-organ disease. While 80%–90% of transplant recipients are infected, only 30%–40% develop active illness. Diagnosis involves colonoscopy with biopsy (polyps or pseudotumors). This case reports rare inflammatory and adenomatous polyps in a patient with CMV inclusions in an ascending colon polyp. CMV in immunocompetent colon tissue is unusual and may indicate underlying inflammation increasing susceptibility to infection. Case Description/Methods: A 73-year-old man with hypertension, benign prostatic hyperplasia, and ischemic heart disease was transferred for screening colonoscopy. Labs showed white blood cell count 6.7, neutrophil count 4.24, hemoglobin 14, platelets 228, C-reactive protein 1.3, Cr 76, and fecal calprotectin 176. He denied diarrhea, bleeding, or abdominal pain, with no family history of cancer and no weight changes. Colonoscopy revealed a 1.6 cm semi-pedunculated polyp in the proximal ascending colon, which was removed with en bloc resection. A 4 mm sessile polyp in the distal sigmoid was also excised. The rest of the colon appeared normal. Discussion: This case involves a non-immunocompromised patient with CMV inclusions in a colonic polyp, showing about 7 infected cells with viral cytopathic changes. A low-grade tubular adenoma was also found in the sigmoid colon, indicating potential neoplastic risk. CMV in the GI tract is rare in healthy hosts, but colitis can occur in older patients or those with chronic conditions like diabetes, coronary artery disease, or renal disease, especially after ICU stays. Endoscopy reveals 3 typical CMV colitis patterns: pseudomembranous, diffuse ulcers, and ulcerative types, sometimes with polyps or pseudotumors mimicking cancer. Irregular ulceration has 100% specificity for CMV, and wide mucosal defects 95%. Pseudo tumors are rare but can resemble malignancy, potentially leading to unnecessary colectomy. However, CMV in polyps does not support a direct role in cancer development, and studies have not found CMV DNA or proteins in colorectal cancers. CMV can also cause postoperative complications after colectomy or coexist with lymphoma. In asymptomatic, immunocompetent patients, incidental CMV findings typically don’t require treatment or follow-up, as infection is usually self-limited and asymptomatic without diarrhea, pain, or bleeding.