Breast Lump Investigations
1. Imaging
Under 30: Ultrasound first (dense breast tissue limits mammogram sensitivity) Over 30: Mammogram first (detects microcalcifications and masses well)
MRI is reserved for high-risk patients (BRCA carriers) or equivocal cases. What it does: Breast MRI uses gadolinium contrast and relies on neovascularity. MRI picks up any area of increased vascularity. That includes cancer, but also fibroadenomas, fibrocystic change, proliferative lesions, fat necrosis, inflammatory changes, and normal hormonal enhancement. Sensitivity for invasive cancer is around 95–99%, far exceeding mammography (~85%) and ultrasound. Specificity is around 70–80%, meaning a significant false-positive rate. The consequences of this are substantial:
2. Biopsy
• FNA — for cysts (both therapeutic drainage + cytology) • Core biopsy — for solid masses (provides histology/architecture — preferred for diagnosis) • VAB (Vacuum-assisted biopsy) — for microcalcifications seen on mammography Core biopsy is the standard for solid lumps because it gives histology, not just cytology.