Fluid Buildup After Lipoma

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What you describe is a seroma, or collection of serum in the empty raw space where the lipoma used to be. The back seems to have a propensity to develop these and drains are often removed there if a large one is removed but usually not in the front over the ribs unless there are special circumstance. Essentially it is your surgeons judgement at the time that makes this decision.. Fortunately it will  resolve but some are persistent and take a long time. Occasionally a new drain needs to be placed. An elastic vest is helpful, decreasing movement associated with exercise, and in rare cases injection of tetracycline with a drain in place is required (see below reference).

What you are experiencing seems normal.  Your very early after surgery.  Fluid accumulation is not uncommon.  Continue to follow closely with her plastic surgeon.  This will resolve given more time.  You should also know that there is always a chance of having a fluid collection such as a seroma.  If you have this, your plastic surgeon will be able to diagnose and treat this very efficiently.

After a lipoma surgery, it is possible to develop a collection of fluid in the area. If your surgeon anticipated this day would choose to put a drain at the site to help remove the fluid until your body can absorb the excess fluid on its own. If you have a fluid collection without a drain, your best that is to be seen by your surgeon who may elect to place a small needle into this collection and withdraw fluid. This will allow the wound heal as best possible. Your surgeon should recommend compression at this site to help prevent the reinstallation of fluid.