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Your Breast Pathology Report: Benign Breast Conditions

Biopsy samples taken from your breast are studied by a doctor with special training, called a pathologist. After testing the samples, the pathologist creates a report on what was found. Your doctors will use this report to help manage your care.

The information here is meant to help you understand some of the medical terms you might see in your pathology report after a breast biopsy, which might be a needle biopsy or a surgical (open) biopsy. 

In a needle biopsy, a hollow needle is used to remove samples from an abnormal area in your breast. In some situations, a surgical biopsy might be needed. This can be either an incisional biopsy, in which only part of an abnormal area is removed, or an excisional biopsy, which removes the entire abnormal area, often with some of the surrounding normal tissue. An excisional biopsy is much like a type of breast-conserving surgery called a lumpectomy. 

Terms describing benign non-cancerous changes 

  • Adenosis
  • Sclerosing adenosis
  • Apocrine metaplasia
  • Cysts
  • Columnar cell change
  • Columnar cell hyperplasia
  • Collagenous spherulosis
  • Duct ectasia
  • Columnar alteration with prominent apical snouts and secretions (CAPSS)
  • Papillomatosis
  • Fibrocystic changes

All of these are benign (non-cancerous) changes that the pathologist might see. These conditions generally do not need to be treated unless they’re causing bothersome symptoms. Most of these conditions do not affect future breast cancer risk. More information about many of these can be found in Non-Cancerous Breast Conditions

Fat necrosis

Fat necrosis is a benign (non-cancerous) condition that is not linked to cancer risk. It is most often caused by trauma (injury) to the breast. It can also develop after breast surgery or radiation treatment, although it may also be seen even if none these have happened. 

Usual ductal hyperplasia (UDH)

UDH is a common, benign (non-cancerous) finding in which there is an overgrowth of cells lining the milk ducts (tiny tubes) in the breast, but the cells look very close to normal. (It might also be described as moderate or florid hyperplasia of the usual type, without atypia.)

UDH does not need to be treated, although it appears to be linked with a slightly increased risk of getting breast cancer in the future.

Radial scar or complex sclerosing lesion

These are terms for a benign (non-cancerous) finding that looks like a scar when seen under a microscope (although it is not a scar). 

If radial scars are seen after an excisional biopsy, usually no further action is needed.

However, if they are found on a needle biopsy, it isn’t so simple. If the area is small and is entirely removed by the needle biopsy, or if it is unrelated to what was seen on the mammogram, then no further treatment may be needed. For lesions that are larger or not entirely removed by the needle biopsy, more tissue from that area might need to be removed because sometimes radial scars are found near something more serious that may need to be treated.

If your report mentions radial scars, talk with your doctor about what is best in your case. 

Papilloma (or intraductal papilloma)

An intraductal papilloma is a type of benign (non-cancerous), wart-like growth within a milk duct.

If a papilloma is found on an excisional biopsy, no further treatment is usually needed.

When a papilloma is diagnosed on needle biopsy, it isn’t so simple. If the papilloma is small and what was seen on the mammogram looked like a papilloma (and not something more serious), no further treatment may be needed (unless it’s causing bothersome symptoms such as pain or nipple discharge). However, the doctor may recommend removing more tissue in the area to be sure there isn’t anything more serious nearby.

Talk with your doctor about what is best in your case. 

Flat epithelial atypia

Flat epithelial atypia is not cancer. Sometimes, though, it is found near something more serious.

If flat epithelial atypia is found on an excisional biopsy, most often no further action is needed.

If flat epithelial atypia is seen on a needle biopsy, your doctor may recommend that some of the tissue around the biopsy site be removed with surgery. Another option might be to just watch the area with mammograms in the future.

Because the best way to treat flat epithelial atypia is not clear, if your biopsy showed flat epithelial atypia, it’s important to talk with your doctor about it. 

Fibroadenoma, phyllodes tumor, or fibroepithelial lesion

Fibroadenoma is the most common benign (non-cancerous) tumor in the breast. If it is diagnosed by needle biopsy and what was seen on the mammogram looked like a fibroadenoma (and not something more serious), it doesn’t need to be removed and can be watched without further treatment. If the tumor is growing or causing problems with the way the breast looks, it may be removed. 

A phyllodes tumor is a very rare breast tumor that develops from the cells in the stroma (connective tissue) of the breast. Other names for these tumors include phylloides tumor and cystosarcoma phyllodes.

These tumors are usually benign, but they can grow quickly and might come back and make the breast look abnormal if not removed completely.

Rarely, these tumors can be malignant (cancer). Some malignant phyllodes tumors might spread beyond the breast, although this happens less often than with more common types of breast cancer.

If a phyllodes tumor is diagnosed on needle biopsy, it is most often treated by removing it completely (often with some type of breast-conserving surgery). 

Sometimes it might be hard for a pathologist looking at a needle biopsy to tell for sure if a growth (tumor) is a fibroadenoma or a phyllodes tumor. In that case, the pathologist may call it a cellular fibroepithelial lesion or a benign fibroepithelial neoplasm. Because it could be a phyllodes tumor, the tumor is most often treated by removing it completely.

Microcalcifications or calcifications 

Microcalcifications or calcifications are small calcium deposits that can be found in both non-cancerous and cancerous breast lesions. They can be seen both on mammograms and under the microscope.

Because certain calcifications can be found in areas containing cancer, their presence on a mammogram may lead to a biopsy of the area. Once the biopsy is done, the pathologist looks at the removed tissue to be sure that it contains calcifications. If the calcifications are there, the doctor knows that the biopsy sampled the correct area (the abnormal area on the mammogram). 

Special lab tests that might be done on biopsy samples

  • High molecular weight cytokeratin (HMWCK)
  • CK903
  • CK5/6
  • p63
  • Muscle specific actin
  • Smooth muscle myosin heavy chain
  • Calponin
  • Keratin 

These are special tests that might be used to help diagnose different types of breast lesions. Not all biopsy samples need these special tests. Whether or not your report mentions these tests has no bearing on the accuracy of your diagnosis. 

The American Cancer Society medical and editorial content team

Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as editors and translators with extensive experience in medical writing.

Last Revised: July 7, 2023

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