**Acknowledgements**

We acknowledge the contributions from Drs. Scott Sanders and Farah Sandhu of the Histopathology Department, South Warwickshire NHS Foundation Trust and University of Warwick, UK. This chapter was supported by the Departments of Gastrointestinal Surgery, Histopathology and Radiology of the National Health Service, South Warwickshire NHS Foundation Trust, UK. We also acknowledge support of the School of Medicine, University of Warwick, UK, and the Institute of Cancer and Genomics, University of Birmingham, UK. We would also like to thank Dr. N Pargass for her help in verifying the references in finalising this chapter.
