Brown streak after mole removal (Photo)

This is a recurrent nevus. In simple terms there were a few nevus cells that didn't get removed and they have grown in the scar. There is nothing about the recurrence that makes it likely to be different than the pathology showed, which was benign. Scar tissue does not cause benign nevi to turn malignant. However, a dermatologist looking at this under dermoscopy (magnified imaging) may not be able to tell if there are changes happening long term because the scar disturbs the standard pigment pattern. Also, Nevus cells in scar tissue can look atypical to dermatopathologists, especially if they don't have access to the original pathology specimen. If it doesn't bother you, don't worry about it. If it worries you, get it re-excised, it will give you piece of mind.