An Overview of Papillary Carcinoma of the Breast

Papillary carcinoma of the breast, also known as intraductal papillary carcinoma, is a rare type of breast cancer accounting for only 0.5 percent of all invasive breast cancers. Invasive cancers begin growing into the milk ducts of the breast and move to invade fibrous or fatty issue outside the duct.  Papillary carcinomas are most often diagnosed in women who have already gone thorough menopause. Interestingly, diagnoses of papillary carcinoma in men appear to be higher than other types of male breast cancer. 

The name "papillary carcinoma" comes from the finger-like appearances, called papules, which can be seen when the cancer cells are looked at under a microscope.  Papillary carcinoma is often found with ductal carcinoma in situ (DCIS), which is a type of early stage breast cancer confined to a milk duct. Most papillary tumors are benign (not cancerous).  When papillary tumors are malignant, it is because they include both in situ cells, which haven’t spread outside the duct, and invasive cells that have begun to spread.

Papillary breast tumors are often small and positive for estrogen and/or progesterone receptors (ER/PR+) and negative for the HER2 receptor. Papillary breast cancers are also less likely to affect the lymph nodes, are more responsive to treatment, and may offer a better prognosis than other types of invasive ductal cancers. 

Papillary carcinoma is sometimes misdiagnosed as intraductal papilloma or papillomatosis. 

Intraductal papilloma is a non-cancerous condition in which a tiny wart-like growth in breast tissue punctures a duct. Intraductal papillomas grow inside the breast's milk ducts and may cause benign nipple discharge.

Papillomatosis is a kind of hyperplasia, another non-cancerous condition which may occur in the ducts and causes cells to grown larger and faster than normal.

Papillary carcinoma may not be felt during a breast self-exam. It is usually found during a routine mammogram (breast imaging) as a well-defined mass behind or just beyond the areola.

Some papillary carcinomas may create a lump large enough to feel with the fingers, and that may cause breast tenderness. Discharge is also possible. Most papillary carcinomas, however, don't cause any symptoms.

Anyone can develop papillary carcinoma of the breast and researchers do not really know what causes it develop. However, some people have an increased risk for this type of breast cancer.

You may have an increased risk if:

• You are female: Papillary breast carcinoma can affect men, but women have a higher risk for the condition. 
• You are over age 60 and/or post-menopausal: Papillary breast cancers are more common in women in their 60s and women of any age who are post-menopausal.
• You are African American: Research shows black women are more likely to have papillary breast carcinoma, especially in advanced stages. 

Papillary breast cancer is diagnosed much like another types of breast cancer, with mammograms, ultrasound, breast MRIs, and tissue biopsies. Imaging alone is not enough to make a diagnosis of papillary breast carcinoma and other testing, especially biopsies can be helpful in this regard.

A tissue biopsy for papillary breast carcinoma involves taking a sample of the tumor and examining it under a microscope. The cancer cells appear in finger like projections (papules) distinguishing them from cells that would be apparent in other types of breast cancer. 

Treatment for the papillary breast cancer depends various features of the cancer, including size of the tumor and grade (how quickly cells divide and if other types of cells are involved), hormone receptor status or HER2 status, as certain treatments can target the specific nature of the cancer. Treatment is offered based on these aspects of your cancer and may include:

• Lumpectomy: Removal of the non-invasive cancer with a margin of surrounding tissue
• Mastectomy: All the breast tissue, including the nipple and the areola is removed.
• Radiation: Radiation is usually given after a lumpectomy to reduce the risk of the cancer coming back in the same breast. It may also be given to the lymph nodes in the arm, especially after a mastectomy and if the breast cancer is invasive.
• Chemotherapy: Chemotherapy destroys cells and may be offered depending on the grading of the tumor, hormone receptor and HR statues and if lymph nodes are affected.
• Hormone therapy: Certain hormones, such as estrogen, stimulate cancer cell growth. Hormone therapy drugs can block the effect of estrogen on cancer cells. Papillary breast cancer cells will be tested to determine if estrogen binds to them and if it does, then hormone therapy can be helpful. With cancers that are negative for hormone receptors, hormone therapy is not effective.
• Target therapy: Targeted therapies block growth and spread of cancer cells. The most widely used target therapy is Herceptin (trastuzumab). Herceptin has been found to be very effective for treating HER2-positive breast cancers. It is not helpful for HER2-negative cancers.

 A Word from Verywell

A diagnosis of breast cancer, regardless of the type, can make a person feel lonely and even isolated from loved ones. Many people find it helpful to reach out to others going through the same experience. Cancer support groups are available both online and in your community. They will help you to get in touch with others who share your worries and can offer some first-hand experience on coping with your diagnosis, and making sense of available treatment options. If you would like further information and support about breast cancer, the American Cancer Society is a great place to start. Your doctor's office may also have information.