Hello Welcome in H.C.M. I have gone through your query regarding symptoms / differential diagnosis of boil in ear / cyst. Most of the time cyst develops in ear lobule, poaterior aspect of pinna and comparitively less in the ear canal, while Boil develops mainly in the outer part of ear canal. Boil is always associated with pain and tenderness while on the otherhand cyst is painless until it gets infected. Next important difference is that boils are having eye while cyst doesn t. In both situations you will get clogged ear. Boil is treated by conservative mode while cyst can be manage only by surgery. Regards.