Decreasing trend has occurred in incidence of colorectal cancer in developed countries. A shift from left to right in location of colorectal cancer has been recognized,which may be associated with colonoscopy screening,aging population,diet structure modification,increased incidence of cancer and diabe-tes. Factors including sex,race and education may also play a role to some extent. Right-sided intestinal cancers have higher proportion of poor differentiation,terminal stage and mucinous component. Complications and second primary intestinal cancer are more common in right-sided intestinal cancers. Left-sided intestinal cancers tend to be well differentiated and at relatively early stage at diagnosis. With respect to molecular mecha-nism,right-sided cancers are associated with mismatch repair system,while left-sided cancers are related to p53 mutation. Based on the differences in clinicopathology and genetics,it′s implied that left-sided and right-sided intestinal cancers may belong to two different kind of disease. It′s suggested that attentions should be paid differently according to their respective characteristics in clinical practice and trials.

Objective To investigate the clinical manifestations and imaging features of isolated cortical vein thrombosis (ICoVT).Methods The data of patients with ICoVT admitted and treated in Shengjing Hospital of China Medical University from 2005 to 2015 were collected.Their clinical manifestations and imaging features were analyzed.Results A total of 104 patients with cerebral venous sinus thrombosis were enrolled.Seven (6.7％) of them with ICoVT were enrolled in the analysis.There were 6 women (85.7％).Their average age was 35 years (range 25-46 years).Headache (n =6;85.7％),seizures (n=5;71.4％),and limb paralysis and numbness (n =4;57.1％) were the most common clinical manifestations.All patients underwent head CT,MRI,and magnetic resonance venography (MRV).Focal cerebral tissue edema (n =5;71.4％) and hemorrhagic infarction (n =3;42.9％) were the most common imaging features.Susceptibility weighted imaging of 3 cases revealed cord-like hypointensity,indicating the formation of venous thrombosis.The clinical symptoms of all patients were relieved after anticoagulant therapy.They were followed up for 1.5 years and no recurrence was observed.Conclusion Headache and seizures are the most common clinical symptoms of IcoVT.Imaging is mostly manifested as focal cerebral edema or hemorrhagic infarction.