The four most common diagnoses for a breast lump are: • Benign cystic change (also known as fibrocystic change, fibroadenosis, or benign breast change) • Fibroadenoma • Cyst • Carcinoma If we consider women of all ages, there are a number of other potential diagnoses: • Fat necrosis • Periductal mastitis • Abscess • Galactocele • Phyllodes tumour • Sarcoma • Duct papilloma • ‘Non-breast’ lumps, e.g. lipoma, sebaceous cyst, prominent costal cartilage/rib. The age of the patient is one of the most useful pieces of information for narrowing the differential. As an approximate guide, the most common diagnoses in the following age groups are: • <30 years: physiologically normal lumpy breast; benign cystic change; fibroadenoma; abscess (if breast-feeding); galactocele (if breast-feeding) • 30–45 years: benign cystic change; cyst; abscess (especially smokers); carcinoma • 45–60 years: cyst; abscess (smokers); carcinoma • >60 years: carcinoma ▲ Note: It is worth emphasizing that breast cancer is possible in all ages, is common, and is potentially very serious. Therefore you must exclude it in any presentation of breast lump, regardless of how benign it seems. Failure to diagnose breast cancer is one of the most common malpractice claims in the USA. Galactoceles may occur during or shortly after the cessation of lactation. They may present as a firm mass (often subareolar) and are caused by the obstruction of a lactiferous duct. The duct gradually becomes more distended with milk and epithelial cells, and may rarely be complicated by a secondary infection leading to abscess formation. Clinically, a galactocele is very similar to a cyst on examination. In addition, lactating women are predisposed to mastitis (whether or not they have a galactocele). The causative organisms are usually skin commensals such as Staphylococcus aureus or Staphylococcus epidermidis—this is in contrast to the periductal mastitis and abscess formation seen in older women, in whom anaerobic bacteria may also be implicated. Two of the greatest risk factors for breast cancer are being female and increasing age. Otherwise, the following are recognized as important factors: • Previous breast cancer • Family history of breast cancer. Suspicions should be raised if: ■ Three close blood relatives (on the same side of the family) develop breast cancer at any age
Periductal mastitis and mammary duct ectasia in a male.
