Brown Spots Beside Breast Lift Scars

Hyperpigmentation is the response of melanocytes to trauma.  Surgical incisions are traumatic and hyperpigmentation can be a response to this.  Most of the time it will fade as the inflammation subsides over months.  Bleaching creams can help but they should be used judiciously.

There are a few causes for this:
Any scar which is expsosed to prolonged inflammation (especially in a dark skinned individual) can develop post-inflammatory hyperpigmentation.
Inflammation can be caused by:

prolonged sun exposure
skin blisters
tape reaction
low grade fungal infections
excessive moisture
suture (stitch) reactions
etc

Postinflammatory hyperpigmentation resolves over time but it may take a year or two. Occasionally mild steroid creams may help but I would consult your physician.
There is one other possibility: retention of areolae. In the case in which a very large areola is reduced, it may not be possible to excise the outer areolae. some of it can be transferred to the vertical scar. This will make the vertical scar look like it is surrounded by a mole when it really is the areola.
I hope this answers your question.