Pseudolumps Are Benign Breast Lumps

Your mammogram may show cysts, fibroadenomas, tumors, or other lumps, and these may be made up of normal breast tissue, other kinds of tissue, or a foreign substance. Sometimes these kinds of lumps are called "pseudolumps." What exactly are pseudolumps and what are the causes?


There are many conditions which can cause breast lumps, both cancerous and benign, and lumps may occur at any age. Cancerous lumps include the different types of breast cancer. Benign breast lumps, by definition, are those which are not malignant and therefore will not spread. Some benign lumps may be associated with an increased risk of developing breast cancer.

Benign Breast Lumps

There are many causes of benign breast lumps, but these can be broken down into three main classes:

  • Cysts: Breast cysts are fluid-filled structures that may come and go with your menstrual cycle.
  • Fibroadenomas and other benign tumors: Fibroadenomas are solid lumps which often feel smooth, rubbery and are usually mobile under the skin. They may change with your menstrual cycle and are most common in women between the ages of 15 and 30.
  • Pseudolumps: Breast pseudolumps are not cysts or growths of benign or malignant cells, but rather scar tissue, dying fatty tissue, pieces of silicone, or even a rib. In other words, they are faux lumps that don't fit into the categories of either benign breast tissue growths or cancer.

Breast Pseudolumps

Breast pseudolumps are not cancerous, nor are they a collection of abnormal but benign cells (such as in a fibroadenoma). Possible causes include:

  • Scar tissue: Scar tissue in the breast may occur after a breast injury, radiation, or any type of surgery including procedures to remove both benign and cancerous lumps and breast reconstruction. (This scar tissue is different from radial scars which can't usually be felt and can be precancerous).
  • An area of fat necrosis: Fat necrosis of the breast literally means "dead fat" and can be caused by trauma (such as seatbelt or airbag injuries after a car accident), surgery, or radiation therapy. The lumps are often fairly hard, like thickened skin, and are more common superficially in the area surrounding the nipple. For a fourth of women, there is notable bruising or discomfort. Fat necrosis can be frightening as these pseudotumors can both feel like cancer on palpation and look like cancer on a mammogram.
  • Hardened silicone: Silicone pseudolumps may be the result of breast augmentation injections or leaking implants.
  • Other tissues outside the breast: Other tissues, for example, a rib pressing on and compressing breast tissue, can be mistaken for abnormal breast tissue.

Can You Feel a Pseudolump?

Your breasts will always have a characteristic texture with their own cyclical lumpiness. Hormonal ebb and flow affect the lumpiness of your breast tissue, which is why you should always do your breast self-exam at the same time each month. Pseudolumps can feel more prominent than other breast tissue, particularly if they are near your skin. These breast masses may feel hard or soft, depending on what is inside of them (fat necrosis may feel softer whereas a rib may feel very hard).

Sometimes a pseudolump may feel squishy. They may or may not be mobile when you feel them, depending on the cause.

Pseudolumps and Your Mammogram

A mammogram or ultrasound can help your doctor see what the lump may be. If you have dense breast tissue or are nursing, it may be difficult to get clear results. A radiologist will be able to diagnose most common breast masses but may recommend more testing if there is some doubt about the composition of a breast lump.

If Pseudolumps Are Suspected, What Happens Next?

What happens next if your doctor suspects a pseudolump depends on your medical history and the characteristics of the lump. She may recommend observing the abnormal finding or instead recommend further imaging. A definite diagnosis can only be made with a biopsy, such as a core needle biopsy. The resulting tissue sample will reveal the true composition of the lump.

Bottom Line 

Pseudolumps are areas of tissue in the breast which are not cancer nor are they typical benign breast lumps. They may be due to the leakage of silicone, scar tissue, the breakdown of fat in the breast, or even simply be a rib that can be palpated through the breast. Injuries to your breast as well as surgery and radiation therapy can make some of these pseudolumps more likely to occur. The important step is to come up with a diagnosis that both you and your doctor are comfortable making, with special attention to making sure nothing is missed in the process.

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