What types of IPMN exist?
There is a main duct and a side-branch type.
Are IPMN lesions exclusively malignant?
Lesions can be benign or malignant or benign and become malignant. Some work has been done suggesting duct wall nodules and enhancement of the MPD walls are signs of malignant MPD or mixed type IPMNs on MRI (see reference 2). This diagnostic difficulty if partly why there is no consensus on treatment.
Cystic lesion in the tail of pancreas, with a 'bunch of grape' appearance. It is continuous with the main pancreatic duct.