1. 核子醫學科 陳明宗 醫師 財團法人 新光吳火獅紀念醫院 2002.11.23 Bizarre Location of colorectal Cancer

2. A 59-year-old man with non-specific medical history except tinnitus and vertigo. He came to our PET center for a health examination and a hot spot of increased FDG uptake was noted at RUQ of the abdomen. Under the impression of colon cancer he received colonoscopy and lower GI double contrast series for comparison. Brief history

3. FDG-PET image on Nov/14/2001

4. Lower GI double Contrast series on Nov/16/2001

5. PET Lower GI double contrast series

6. The RUQ lesion was thought to be a ascending colon tumor in the PET images. However, colonoscopy performed next day revealed a sigmoid colon cancer measured 2cm in size at 25cm level. Our surgeon thought that there were 2 primary colon cancer in different locations. Under this confusing situation, LGI double contrast series was performed and the result proved that there was only one tumor located in redundant sigmoid colon. Surgery was performed 3 days after LGI series. The pathology report proved that this tumor was adenocarcinoma of Dukes ’ B2 without any lymph node metastasis.

7. Teaching point We have to keep in mind that the precise location of GI tract can vary in different individuals. Rare situation does exist and our physicians must judge these images very carefully. If there is any different result between different examinations, other examination should be performed to do an accurate diagnosis.

8. Reference 1.Gupta NC, Falk PM, Frank AL. et al. Pre-operative staging of colorectal carcinoma using positron emission tomography. Nebr Med J 1993;78:30- 35 2. Akhurst T, Larson SM. Positron emission tomography imaging of colorectal cancer. Semin Oncol 1999;26(5):577-583