Plasma Cell Mastitis

Plasma cell mastitis presents with pain, tenderness, and nipple discharge. Microscopically, there is periductal inflammation with a diffuse plasma cell infiltrate around ducts and lobules. Ductal hyperplasia may be present and may even be atypical. Xanthogranulomatous response may be seen. With chronicity, the overlying skin becomes discolored with firm to hard consistency. Clinical distinction from mammary carcinoma may be difficult.