How could I draw lines in a vector mask ? I want to reach the same effect like if I were working with shapes, because the image needs to be vector and scalable.

For example, if I draw an elipse, then fill a layer with white and reveal vector mask associated to this path, I will be seeing a white circle. 

What I want to do is the same, but instead of seeing a white circle, I want to see the circle stroke, like if I have stroked the path with white color, is this possible?