This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Abdominal Radiography, Subject name: Radiology
Apple core sign in barium enema is seen with? 
Select and explain. 
A. Ileocecal tuberculosis, B. Carcinoma esophagus, C. Colon carcinoma, D. Achalasia cardia
C: Colon carcinoma
Answer: C: Colon carcinoma 
Explanation: ANSWERS: (C) Colon carcinomaREF: Suttons Radiology 7th edition volume 1 page 625, Fundamentals of diagnostic radiology William E. Brant, Clyde A. Helms - Page 851, style="font-size: 1.04761904761905em; font-family: Times New Roman, Times, serif; margin: 0 0 8pt 8px; text-indent: 0; text-align: left">Apple core sign:The apple core sign, also known as a napkin ring sign, is most frequently associated with constriction of the lumen of the colon by a stenosing annular colorectal carcinoma. The same term has also been used for the circumferential erosion of the femoral neck seen in synovial o steochondromato sis