Invasive papillary carcinomas of the breast are rare, accounting for less than 1-2% of invasive breast cancers. In most cases, these types of tumors are diagnosed in older women who have already been through menopause. An invasive papillary carcinoma usually has a well-defined border and is made up of small, finger-like projections. Often it is grade 2, or moderate grade, on a scale of 1 to 3 — with grade 1 describing cancer cells that look and behave somewhat like normal, healthy breast cells, and grade 3 describing very abnormal, fast-growing cancer cells. In most cases of invasive papillary carcinoma, ductal carcinoma in situ (DCIS) is also present. (DCIS is a type of cancer in which the carcinoma cells are confined to the breast duct.)
For information about how papillary invasive carcinoma is treated, see the section on treatment for invasive ductal carcinoma.