When Carcinoembryonic Antigen Misleads: A Benign Cause of Tumor Marker Elevation

Carcinoembryonic antigen (CEA) is a commonly used tumor marker, primarily for the surveillance of colorectal and other gastrointestinal malignancies. However, its diagnostic specificity is limited, as CEA levels may be elevated in several benign conditions. This case report aims to highlight the potential diagnostic confusion and psychological distress caused by incidental CEA elevation in asymptomatic individuals when tested outside of an appropriate clinical context. We describe the case of a 39-year-old Kuwaiti woman who underwent a routine health check-up at a private laboratory, during which CEA was measured despite the absence of cancer-related symptoms. Her CEA level was markedly elevated, prompting anxiety and a cascade of investigations. Clinical history, physical examination, laboratory testing, endoscopic procedures, and imaging were employed to determine the cause of elevation. The patient's elevated CEA level (49.02 ng/mL) was not associated with any detectable malignancy. Her past medical history included a laparoscopic sleeve gastrectomy a year earlier. Clinical assessment revealed chronic dyspepsia, anemia, and right upper quadrant tenderness. A comprehensive workup, including colonoscopy, upper gastrointestinal (GI) endoscopy, and contrast-enhanced CT imaging excluded neoplastic processes. Abdominal ultrasound revealed chronic calculous cholecystitis. Following laparoscopic cholecystectomy, her symptoms improved and repeat CEA levels normalized, confirming a benign inflammatory etiology. This case illustrates the limitations of CEA as a screening tool and the importance of interpreting tumor markers within the appropriate clinical context. Routine ordering of tumor markers in asymptomatic patients can result in unnecessary anxiety, diagnostic delays, and resource use. Clinicians should rely on symptom-guided evaluations rather than indiscriminate testing.