Education

Symptoms & Diagnosis

GM can look and feel alarming. Knowing what to watch for — and what your care team is checking for — can help you ask better questions.

Common Symptoms

  • Breast lump or mass
  • Breast pain or tenderness
  • Redness over the affected area
  • Swelling and skin thickening
  • Nipple changes or retraction
  • Abscess formation
  • Draining wounds or fistulas
  • Fatigue and emotional distress

How GM Is Diagnosed

Clinical Examination

A breast specialist evaluates symptoms, examines the breast, and reviews your medical and reproductive history. GM is often initially mistaken for infection (mastitis) or cancer.

Imaging

  • Ultrasound — the most common first-line imaging study
  • Mammogram — often performed to exclude malignancy
  • MRI — sometimes used for difficult or recurrent cases

Imaging findings in GM are frequently nonspecific and can overlap with cancer and infection, which is why imaging alone is not enough to make the diagnosis.

Biopsy

A core-needle or excisional biopsy is generally required to confirm the diagnosis. Pathology looks for non-caseating granulomas centered on breast lobules and rules out cancer, tuberculosis, sarcoidosis, fungal infection, and other granulomatous diseases.

Microbiology

Cultures may be ordered to look for bacterial involvement, particularly Corynebacterium species, which can influence treatment decisions.

Medical disclaimer. This page is educational and is not a substitute for diagnosis or treatment by a qualified medical professional. Information is reviewed periodically against published literature. Always consult your physician.