Breast disease and mammography
10.1
Mammographic features of breast lesions
| Lesion characteristics | Benign | Malignant |
| Opacity | Smooth margin | Ill-defined margin, stellate |
| Speculate, comet tail | ||
| Low density | High density | |
| Homogeneous | Inhomogeneous | |
| Thin ‘halo’ | Wide ‘halo’ | |
| Calcification (see 10.3) | ± | ± |
| Surrounding parenchyma | Normal | Disrupted |
| Nipple/areola | ± Retracted | ± Retracted |
| Skin | Normal | ± Thickened |
| Cooper ligaments | Normal | May be thickened/increased |
| Ducts | Normal | Focal dilatation |
| Subcutaneous/retromammary space | Normal | ± Obliterated |
10.2
Calcification
| Definitely benign (see figure, p. 247) | Probably benign | Suspicious of malignancy |
| Arterial, tortuous, tramline (1) Smooth, widely separated radiolucent centre (2) Linear, thick, rod-like ± radiolucent centre (3) Egg-shell, curvilinear margin of cyst, fat necrosis (4) Pop-corn (fibroadenoma) (5) Large individual > 2 mm (6) Floating, seen on lateral oblique, milk of calcium cysts (7) |
Widespread, both breasts Macrocalcification of one size Symmetrical distribution Widely separated Superficial distribution Normal breast parenchyma |
Microcalcification, segmental* Pleomorphic, linear, branching, punctuate* Associated suspicious soft-tissue opacity Eccentrically located in soft-tissue mass Deterioration on serial mammography |
Examples of definitely benign calcification:
10.4
Benign lesions with typical appearances
1. Fibroadenoma – rounded, lobulated, well-defined homogeneously dense soft-tissue opacity with eccentrically sited ‘pop-corn’ calcification.
2. Intramammary lymph node – well-defined, approximately 1.0 cm in diameter soft-tissue opacity, often with an eccentric radiolucency situated most often in the upper outer quadrant of the breast.
3. Lipoma – large, rounded, radiolucent, well-defined.
4. Lipid cyst – well-defined, multiple, lucent, ‘egg-shell’ calcification.
5. Hamartoma/fibroadenolipoma – ‘breast within a breast’ appearance on a mammogram.
10.5
Single well-defined soft-tissue opacity
Benign
3. Intramammary lymph node – intramammary lymph nodes occur in up to 40% of breasts. Causes include breast cancer, lymphoma, melanoma, regional inflammation/dermatitis, fungal infection, tuberculosis/granulomatous disease, foreign body reactions, e.g. gold injections for rheumatoid arthritis, silicone adenopathy, HIV and sinus histiocytosis.
Malignant
1. Cystosarcoma phylloides – usually large, may be benign but have malignant potential (5–10%), calcification rare, median age 45–49, rare < 30 or > 60. High tendency to recur, both in benign and malignant. Malignant lesions metastasize to lung and bone and may invade chest wall.
2. Carcinoma – a small group of carcinomas looks ‘benign’ on mammography; medullary, encephaloid, mucoid, papillary.
10.6
Multiple well-defined soft-tissue opacities
2. Fibroadenomas – 10–20% are multiple.
3. Skin lesions – e.g. neurofibromas.
5. Metastases – melanoma most common, lymphoma second most common non-mammary breast tumour, then lung, ovarian, soft-tissue sarcomas, gastrointestinal/genitourinary malignancy, carcinoid and sporadically thyroid, osteosarcoma, cervical, vaginal and endometrial. Mean survival after diagnosis of metastasis within the breast is < 1 year.
