Figure 4. (a) 51-year-old woman with right iliac fossa pain. CT showed a caecal carcinoma with abnormal pericolic fat. Histopathology of the resected specimen found 2 out of 10 lymph nodes (LN) were involved by tumour, one of which (illustrated) was partially involved by colorectal cancer (C). Despite involvement by metastatic cancer, this small node is not enlarged. The largest involved node in this case measured 8 mm, smaller than the largest uninvolved node (13 mm). Scale bar (top right)=1 mm. (b) 45-year-old woman with abdominal pain. CT showed a caecal carcinoma (there was insufficient intraabdominal fat to allow satisfactory evaluation of the pericolic fat). Histopathology of the resected specimen found 3 out of 11 nodes were involved by tumour, the largest of which was 25 mm, and 8 out of 11 uninvolved nodes, the largest of which was 30 mm, as illustrated. This photomicrograph shows 25% of the latter (tumour-free) lymph node containing reactive follicular hyperplasia. Scale bar (top right)=1 mm (same magnification as Figure 4a for comparison).
