Diffuse Long-segment Colonic Wall Thickening Mimicking Abdominal Tuberculosis: A Diagnostic Challenge Revealing Signet Ring Cell Carcinoma in a 24-year-old Male

Long-segment bowel wall thickening with ascites and omental involvement is usually attributed to abdominal tuberculosis, particularly in areas endemic to tuberculosis. However, certain cancers, like diffuse infiltrative colorectal carcinomas, can mimic the imaging findings. We present a case of a 24-year-old male who presented with long-standing abdominal pain and underwent a contrast-enhanced computed tomography scan, which showed target-like diffuse thickening from the terminal ileum to the entire transverse colon, along with ascites and omental thickening. His CA 19-9 levels were significantly raised at >1000U/ml, posing difficulty in clearly distinguishing it from abdominal tuberculosis. Biopsy from the thickening revealed signet ring cell carcinoma of the colon. In young patients, diffuse colonic thickening with peritoneal involvement can look like tuberculosis. However, raised tumor markers should prompt a thorough search for cancer, even in unusual age groups and presentations.