unfortunately DIEP flaps have more fat necrosis that other microsurgical tummy flaps . It seems that's the trade off : less abdominal problems but more fat necrosis.
This is not dangerous for your health : just a cosmetic issue. It can be addressed with revision surgery
DIEP flap Breast Reconstruction
In the second phase of reconstruction where symmetry procedures are performed small areas of fat necrosis can be contoured. This most common at an edge of the flap. Using fat graft is common in this step to help improve these areas.See your DIEP flap surgeon regarding the mammogram results and an exam.
Fat necrosis following DIEP
Fat necrosis is relatively common following a DIEP reconstruction. If the area is large, or bothersome, you may benefit from excision. Small areas can resolve with no intervention. If you have a large area excised, you may require fat grafting to restore good contour.