What should you know about neutrophilic granulomatous mastitis?

Mastitis means inflammation of breast tissue. In this form, a tissue sample may show neutrophils, which are white blood cells involved in acute inflammation, alongside granulomatous inflammation. The process can produce a tender area, firmness, redness, warmth, swelling, drainage, or an abscess-like collection. A breast lump is a presentation of this inflammatory condition, but a lump can also have many other causes.

The appearance can overlap with bacterial mastitis, a breast abscess, and breast cancer. That overlap is why a clinician may use ultrasound or other breast imaging and may send fluid or tissue for laboratory testing. A biopsy can help identify the pattern of inflammation and exclude other diagnoses. The result needs to be interpreted with your examination, symptoms, imaging, and test findings rather than in isolation.

Arrange a breast assessment if you have a new lump, persistent pain, redness, swelling, skin change, or discharge. Tell the clinician when it began, whether it changes with feeding or the menstrual cycle, whether you have fever, and which medicines or supplements you use. Mention recent pregnancy, breastfeeding, nipple injury, procedures, or previous breast inflammation when relevant.

Treatment depends on the examination and test results. Options may include observation with planned review, antibiotics when infection is suspected, drainage when a collection is present, anti-inflammatory or immune-directed medicine, or surgery in selected situations. Do not start, stop, or reuse antibiotics or steroid medicine without medical guidance. If feeding or expressing milk is painful, a lactation consultation can help review positioning, attachment, and milk removal while your breast problem is assessed.

Seek urgent medical care for rapidly increasing breast swelling or redness, severe or worsening pain, high fever with chills, faintness, confusion, or feeling markedly unwell. These features can signal a significant infection or another problem needing prompt assessment.

Contact a clinician soon if a lump, skin dimpling, nipple inversion, bloody discharge, draining area, or breast change does not settle, returns, or remains after an initial treatment. Persistence does not establish a particular diagnosis, but it does warrant follow-up and sometimes repeat imaging or tissue assessment.

You could ask: What findings support this diagnosis? Do I need imaging, a culture, or a biopsy? Could a collection need drainage? Which treatments are being considered, and what monitoring will I need? Is it safe for me to continue breastfeeding or expressing milk? When should the lump, pain, or skin change be reassessed?