Papillary carcinoma of the breast, also known as intraductal papillary carcinoma, is a rare form of breast cancer, accounting for only 0.5% of all new invasive breast cancer cases.
Under the microscope, papillary carcinomas look like finger-like protrusions called papules. Many papillary tumors are not cancerous; these are called papillomas. When papillary tumors are malignant, it is because they include both in situ cells that have not spread outside the ducts, and invasive cells that have begun to spread.
Although concerning, papillary carcinoma of the breast is less likely to spread to lymph nodes, is more sensitive to treatment, and may offer a better prognosis than other types of invasive ductal carcinoma.
This article will describe the symptoms, causes, diagnosis, and treatment options for papillary breast cancer.
Aggressive cancer begins to grow into the milk ducts in the breast and invade the fibrous or fatty tissue outside the milk ducts.
Types of papillary breast cancer
There are several variants of papillary breast cancer.
Benign (harmless) papillary lesions
- Intraductal papilloma (solitary): a single tumor that grows in the milk duct near the nipple
- Intraductal papillomatosis: a tumor that grows in the milk ducts near the nipple
atypical papillary lesions
- Dysplastic intraductal papilloma: abnormal growth of cells
- DCIS papilloma: ductal papilloma in situ, precancerous lesions
malignant papillary lesions
- Papillary ductal carcinoma in situ: Starts in the milk ducts of the breast but has not spread beyond the milk ducts
- Encapsulated papillary carcinoma: a rare tumor that is contained in one area
- Solid papillary carcinoma: a rare form with solid nodules that mainly affects older women
- Invasive papillary carcinoma: a very rare form of ductal carcinoma
- Invasive micropapillary carcinoma: a variant of breast cancer with a high chance of regional lymph node involvement
Usually, papillary cancer doesn’t cause any symptoms and isn’t detected by breast self-exams.
When they do cause symptoms, you may experience the following:
- a lump large enough to be felt with a finger
- Nipple changes like inward turning nipples
- breast tenderness
Signs of early, metastatic and inflammatory breast cancer
Papillary cancer is most often diagnosed in women who have gone through menopause. Interestingly, the diagnosis of male papillary carcinoma appears to be more common than other types of male breast cancer.
Anyone can get papillary cancer; researchers don’t really know what causes it to develop.
Causes and Risk Factors of Breast Cancer
Papillary cancer is usually found on routine mammograms (breast imaging) as a well-defined mass behind or immediately adjacent to the areola.
Imaging alone is not sufficient to diagnose papillary breast cancer, so mammograms, ultrasound, and/or breast magnetic resonance imaging (MRI) are required in conjunction with tissue biopsy.
A tissue biopsy for papillary breast cancer involves taking a sample of the tumor and examining it under a microscope. The finger-like appearance of cancer cells distinguishes them from cells that are characteristic of other types of breast cancer.
Papillary carcinoma is often found along with ductal carcinoma in situ (DCIS), an early-stage breast cancer confined to the milk ducts.
Papillary carcinoma is sometimes misdiagnosed as intraductal papilloma or papillomatosis.
Intraductal papilloma is a noncancerous condition in which tiny wart-like growths in breast tissue pierce the ducts. Intraductal papilloma grows inside the breast ducts and may cause benign nipple discharge.
Papillomatosis is a hyperplasia, another noncancerous condition that can occur in the ducts and cause cells to grow larger and faster than normal.
Having one or more intraductal papillomas or papillomatosis slightly increases the risk of breast cancer.
Most cases of papillary cancer are low-grade, slow-growing cancers. Many don’t spread far beyond their original site. That said, treatment is important. Options depend on various characteristics of the cancer, including:
- Tumor size (papillary breast tumors are usually small)
- tumor grade
- hormone receptor status
- HER2 status
Papillary breast tumors are usually positive for estrogen and/or progesterone receptors (ER/PR+) and negative for HER2 receptors.
Surgical options include lumpectomy, which removes a margin of non-invasive cancer and surrounding tissue, or mastectomy, which removes all breast tissue (including the nipple and areola).
Chemotherapy destroys cells and may be delivered depending on tumor grade, hormone receptor and HER2 status, and whether lymph nodes are affected.
On the other hand, hormone therapy drugs can block the effect of estrogen on cancer cells. Papillary breast cancer cells will be tested to see if estrogen binds to them. If so, hormone therapy may help.
Targeted therapy can also stop the growth and spread of cancer cells. The most widely used targeted therapy is Herceptin (trastuzumab). Herceptin has been found to be very effective in the treatment of HER2-positive breast cancer. However, it did not help HER2-negative cancers.
Finally, bisphosphonates — bone-building drugs found to help reduce the risk of cancer recurrence in postmenopausal women — also help prevent cancer cells from spreading.
how to treat breast cancer
Papillary carcinoma of the breast is a rare type of breast cancer, accounting for only 0.5% of all new invasive breast cancer cases. It mainly affects women who have already gone through menopause. There may be no symptoms, and you may not notice the lump during the self-exam. This cancer grows slowly and is unlikely to spread to the lymph nodes.
Cancer Support Groups are a great resource for finding people who have first-hand experience with a breast cancer diagnosis. Be prepared that you may not meet other people with papillary breast cancer as it is very rare. Connecting with others coping with a breast cancer diagnosis and receiving treatment is invaluable. However, when discussing your specific situation, your best resource remains your medical team.
Frequently Asked Questions
Is papillary breast cancer hereditary?
Family history does play a role, and it’s important to know yours. If your first-degree relative has this cancer, you may be at higher risk.
Does papillary breast cancer always originate in the breast ducts?
Yes, like many types of breast cancer, this type starts in the milk ducts in the breast.
Can papillary breast cancer grow rapidly?
This type of cancer usually grows slowly and does not grow far from its original site.
What is the prognosis for papillary breast cancer?
Because this cancer is less likely to spread to the lymph nodes, it has a better outcome than some other invasive breast cancers.