Painful Palpable Area in Right Breast Accompanied by a Straw-Colored Nipple Discharge in 22-Year-Old Woman

A 22-year-old female collegiate soccer player complains of a painful palpable area in her right breast accompanied by a straw-colored nipple discharge. Because she is extremely anxious and has had previous excisional biopsies, you decide to perform a lumpectomy.

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After reviewing the H&E stained tissue you decide the most likely diagnosis is: