Any new lump or change in the breast, nipple or armpit should be investigated.
The following methods of examination are commonly used:
- Medical history and physical examination
- Mammography, sometimes supplemented with ultrasound of the breast
- Ultrasound of the breast distinguishes cystic from solid tumors and is the only diagnostic test suitable for adolescent girls.
- Breast MRI (magnetic resonance imaging), in some instances an additional MRI of the breast is required. This may provide additional information about the nature of the lump, its location and extent.
- Fine needle aspiration or tissue biopsy, possibly under ultrasound guidance. Under local anesthesia, a number of cells or a piece of tissue from the tumor are removed and sent for microscopic examination. This is usually sufficient to confirm the diagnosis of breast cancer.
- For non-palpable tumors a stereotactic biopsy can be performed. Under ultrasound or MRI guidance, a guide-wire is placed within the tumor. This allows the surgeon to locate the tumor intra-operatively, where both the wire and surrounding tumor are removed.
- Abnormal fluid discharge from the nipple can be investigated by galactography. A contrast medium is injected through a fine tube into the ducts, before performing a mammogram. This enables visualization and study of any abnormalities of the lactiferous ducts.
- Discharge from the nipple can also be investigated by collecting some fluid on a glass plate, which can be examined for the presence of abnormal cells or blood.