A 23-year-old Caucasian woman, postpartum day 14, brings her new baby daughter in for a two-week checkup. She mentions that her left breast has become diffusely painful and swollen, and this has made...

A 23-year-old Caucasian woman, postpartum day 14, brings her new baby daughter in for a two-week checkup. She mentions that her left breast has become diffusely painful and swollen, and this has made breastfeeding her daughter difficult. What is the most likely diagnosis?

 A. Inflammatory carcinoma

 B. Phyllodes tumor

 C. Acute mastitis

 D. Paget disease