Abstract
BACKGROUND: Colonic schistosomiasis is a significant health issue in endemic areas, presenting diagnostic challenges due to its nonspecific clinical symptoms and radiographic features. This case report highlights a patient with concomitant colorectal cancer and chronic Schistosoma japonicum infection, emphasizing the need for a comprehensive diagnostic approach. CASE PRESENTATION: A 67-year-old male from an endemic region presented with a six-month history of intermittent hematochezia. Initial colonoscopy revealed multiple mucosal elevations in the sigmoid colon and rectum. Subsequent investigations, including CT scans and endoscopic ultrasonography, indicated high echogenic changes and multiple lesions. The patient underwent endoscopic submucosal dissection (ESD), revealing adenocarcinoma of the rectal mucosa and tubular adenoma in the sigmoid colon, both with extensive deposition of Schistosoma japonicum eggs. Postoperative pathology confirmed the diagnosis of moderately differentiated adenocarcinoma with chronic schistosomiasis. CONCLUSION: This case underscores the diagnostic complexity of colonic schistosomiasis, particularly when coexisting with malignancy. The integration of colonoscopy, histopathology, and auxiliary tests is crucial for accurate diagnosis. Clinicians should maintain a high index of suspicion for schistosomiasis in patients from endemic areas presenting with gastrointestinal symptoms. Regular screening and detailed medical histories are essential for early detection and treatment, improving patient outcomes and reducing the risk of misdiagnosis.