Often poor as are usually advanced on time of diagnosis therefore resection options are poor. In addition, metastatic rate is high: malignant tumours are locally invasive and metastasis occurs via draining lymph nodes, haematogenous spread to distant areas. | Often poor as are usually advanced on time of diagnosis therefore resection options are poor. In addition, metastatic rate is high: malignant tumours are locally invasive and metastasis occurs via draining lymph nodes, haematogenous spread to distant areas. |