If your breast was reconstructed using a flap of tissue from another part of your body (called "autologous reconstruction"), in relatively rare cases some of the fat in the flap may not have received enough blood flow. Over time, that fat may be replaced by firm scar tissue that feels like a hard lump. The lump may be as small as a pea or could be a larger, hard mass. It is usually not noticeable until 6-8 months after the surgery, once the tissue flap has softened and the swelling is gone. Doctors call these lumps fat necrosis.
Sometimes smaller areas of fat necrosis will shrink or go away on their own. Larger areas of fat necrosis can be painful and can cause a distortion in the shape or texture of the breast.
Diagnosis of fat necrosis in the tissue flap
Your doctor may recommend that you get an imaging scan, such as a high-resolution ultrasound, to evaluate a lump that could be fat necrosis. Fat necrosis lumps are benign (not cancerous). But during a clinical breast exam and on a mammogram, it may be impossible to tell the difference between fat necrosis and breast cancer. Sometimes, a biopsy is needed for diagnosis.
Treatment of fat necrosis in the tissue flap
If you have a lump that your doctor has confirmed is fat necrosis, it’s not going away on its own, and it’s causing you pain or a distortion in the shape of your breast, you can have it surgically removed.
A plastic surgeon will either cut out (excise) the area of fat necrosis in the breast or suction it out using liposuction. An advantage of using liposuction is that it’s less likely to create a divot in the spot where the fat necrosis was removed. If you do wind up with a divot in your breast from the excision of an area of fat necrosis, your plastic surgeon might reposition the internal tissue to fill it in.
Another option may be to use a small flap reconstruction to fill in that area. In some cases, your plastic surgeon may recommend fat grafting (or “fat injections”) to help add volume after the removal of an area of fat necrosis.
Although fat necrosis most commonly occurs after autologous breast reconstruction, it can also develop after other types of breast surgeries or procedures, radiation therapy, or an injury to the breast.