Papillary breast cancer is a very rare type of invasive ductal
breast cancer that accounts for fewer than 1% of all breast
The name comes from finger-like projections, or papules, which are
seen when the cells are looked at under the microscope.
Many papillary tumors are benign. These are called
Even when a biopsy is negative for cancer, the pathologist often
needs to look at the whole tumor under the microscope to be sure
about the diagnosis. This is why surgery to remove a papilloma is
usually recommended, even if it is thought to be benign.
Malignant papillary tumors are a form of breast cancer. Like
other types of invasive ductal cancer, papillary breast cancer
begins in the milk duct of the breast. Most of the time, papillary
breast cancers include both in situ cells (which have not yet spread
outside of the duct) and invasive cells (which have begun to spread
outside of the duct).
Papillary breast cancers are usually small, and positive for the
estrogen and/or progesterone receptors (ER/PR+) and negative for the
HER2 receptor (HER2-).
Compared to more common types of breast cancers, papillary breast
cancers are less likely to involve the lymph nodes, are more
responsive to treatment, and may have a better prognosis than more
common types of invasive ductal cancer.
Local therapy is aimed at preventing the cancer from coming back in
the breast. Local therapy includes surgery (lumpectomy or
mastectomy), and may include radiation.
Systemic therapy is used to prevent the disease from coming back or
spreading to another part of the body. This may include
endocrine (hormone) therapy, chemotherapy, and therapy that targets
the HER2 protein. Often different types of treatment are used
together to achieve the best result.
The treatment plan will be based on the features of the tumor (type
of cells, tumor grade, hormone receptor status, and HER2 status) and
the stage of the disease (tumor size and node status).