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Pathology FAQ: Benign Breast


When your breast was biopsied, the samples taken were studied under the microscope by a specialized doctor with many years of training called a pathologist. The pathology report tells your treating doctor the diagnosis in each of the samples to help manage your care. This FAQ sheet is designed to help you understand the medical language used in the pathology report.

1. What does it mean if my report says any of the following terms: “adenosis”, “sclerosing adenosis”, “apocrine metaplasia”, “cysts”, “columnar cell change”, “columnar cell hyperplasia”, “collagenous spherulosis”, “duct ectasia”, “columnar cell change with prominent apical snouts and secretions (CAPSS)”, “papillomatosis”, or “fibrocystic changes?

Most of these terms refer to benign growth patterns that have little or no influence on your health. However, there are certain benign conditions diagnosed by core needle biopsy that should prompt a discussion about doing an open surgical biopsy to make sure there is no cancer nearby. These include: Atypical Ductal Hyperplasia (including flat epithelial atypia), Atypical Lobular Hyperplasia, Lobular Carcinoma in situ, complex sclerosing lesion (also known as radial scar), papilloma (especially papilloma with atypia), and mucocele-like lesion.

2. What does it mean if my report says “fat necrosis”?

Fat necrosis can result from traumatic injury to the breast although it may also be seen without any history of trauma. It is totally benign (non-cancerous) and not related to cancer.

3. What does it mean if my report says “usual duct hyperplasia (UDH)”?

UDH is a benign finding that is associated with a slight increase in breast cancer risk. However, since the risk is low, nothing more needs to be done.

4. What if my report says “radial scar” or “complex sclerosing lesion”?

These findings are benign (noncancerous). However, if they are found on needle biopsy, excision of the area may be recommended, because in some cases there may be cancer nearby. If these findings are seen in an excision (lumpectomy), no further action is needed and there is no increased risk of cancer.

5. What does it mean if my report says “papilloma”?

A papilloma is a benign (non-cancerous) growth. That is very similar to the polyps that can be found in the GI tract. When papilloma is diagnosed on needle biopsy, if the lesion is small and the mammogram findings are consistent with a papilloma, no further excision may be suggested. However, in many cases, an excision may be recommended to exclude the presence of a worse abnormality in the breast. The management of a papilloma on needle biopsy is best discussed with your treating physician. If papilloma is found on an excision (lumpectomy), typically no further treatment is needed.

6. What does it mean if my report says “flat epithelial atypia”?

Flat Epithelial Atypia is a form of Atypical Ductal Hyperplasia. If it is diagnosed on a core needle biopsy open surgical excision is usually recommended to exclude a nearby cancer. If flat epithelial atypia is present on an excision (lumpectomy), then typically no further action is needed.

7. What if my report says “fibroadenoma”, “fibroepithelial lesion”, “phyllodes tumor”?

Fibroadenoma is the most common benign (noncancerous) growth in the breast. If it is diagnosed on needle biopsy and the mammographic finding is consistent with a fibroadenoma, it is typically simply followed, with no additional excision. If it is growing or causing symptoms it can be removed. Phyllodes tumor is an overgrowth of the fibrous support cells of the breast. Depending on how the cells look under the microscope phyllodes tumors are classified as benign or malignant. Most phyllodes tumors are benign but complete removal is recommended for all of them. In some cases on needle biopsy it may be difficult for a pathologist to determine whether the growth is a fibroadenoma or phyllodes tumor and terms such as “cellular fibroepithelial lesion” may be used. In these cases, subsequent complete removal is typically recommended.

8. What does it mean if my report mentions “microcalcifications” or “calcifications”?

“Microcalcifications” or “calcifications” are minerals that are found in both noncancerous and cancerous breast lesions and can be seen both on mammograms and under the microscope. Because some calcifications are associated with cancerous lesions, their presence on a mammogram may lead to a biopsy of the area. When they are seen by the pathologist in a biopsy specimen which was obtained because of a mammographic abnormality with calcifications, their presence is included in the pathology report to let the treating physician know that the abnormal area with calcifications seen in the mammogram was successfully sampled. Without accompanying worrisome changes in the breast ducts or lobules, “microcalcifications” or “calcifications” alone have no significance.

9. What does it mean if my biopsy report mentions special studies such as high molecular weight cytokeratin (HMWCK), CK903, CK5/6, p63, muscle specific actin, smooth muscle myosin heavy chain, or calponin?

These are special tests that the pathologist sometimes uses to help make the correct diagnosis of a variety of breast lesions. Not all cases need these special tests. Whether your report does or does not mention these tests has no bearing on the accuracy of your diagnosis.

Navigate our Pathology FAQs and Images

  1. Benign Breast FAQ
  2. Benign Diseases - Atlas of Images
  3. Atypical Hyperplasia
  4. Breast Cancer In-Situ
  5. Breast Cancer
  6. Malignant Tumors - Atlas of Images
  7. Ask an Expert - Understanding Pathology Results

Authors: Jeanne Simpson (Vanderbilt Medical Center), Stuart Schnitt (Beth Israel Deaconess Medical Center), Jonathan I. Epstein (Johns Hopkins Medical Institutions)