fig5

Figure 5. Cross sectional slices from two specimens showing involvement of the circumferential resection margin (CRM) by primary tumour. The first has macroscopically visible tumour extending to the margin and was correctly identified as CRM involved on MRI (left); the second has extensive fibrosis following pre-operative chemoradiotherapy and the post treatment MRI predicted a clear margin, but small microscopic islands of residual viable tumour were present at the CRM (right)