Breast Cancer: Imaging

Breast imaging

The breast can be imaged with
1) mammography
2) ultrasound
3) MRI
Mammography is the most sensitive of breast imaging modalities
Sensitivity is reduced in young women due to the presence of increased glandular tissue
For symptomatic patients, imaging always be performed as part of triple assessment

Mammography
Abnormalities detected on mammography are classified as:
1) Spiculated masses
2) Stellate lesions
3) Circumscribed masses
4) Microcalcification

Spiculated masses
Soft tissue mass with spicules extending into surrounding tissue
95% of spiculated masses are due to invasive cancer
Other causes of spiculated masses include:
Ductal carcinoma in-situ (DCIS)
Radial scar / complex sclerosing lesion
Fat necrosis
Fibromatosis
Granular cell myoblastoma

Stellate lesions
Localised distortion of the breast parenchyma with no perceptible mass lesion
Differential diagnosis of stellate lesions includes:
Radial scar
Invasive cancer
DCIS
Surgical scar

Circumscribed masses
Circumscribed masses should be analysed according to density, outline and size
Differential diagnosis of circumscribed masses includes:
Fibroadenoma
Cyst
Mucinous or medullary carcinoma
Lipoma
Abscess

Microcalcification
Microcalcification is due to debris within the duct wall or lumen
Sole feature of 33% of screen-detected cancers
Malignant microcalcification is usually linear or branching
Benign microcalcification is usually rounded and punctate
Differential diagnosis of microcalcification includes:
DCIS
Invasive cancer
Papilloma
Fibroadenoma
Fat necrosis

Breast ultrasound
Ultrasound is useful in the assessment of breast lumps
Complements mammography and is able to differentiate solid and cystic lesions
Also able to guide fine needle aspiration and core biopsies
Can be used to assess tumour size and response to therapy
In the diagnosis of malignancy it has a sensitivity and specificity of 75% and 97% respectively
Cysts and solid lesions have typical appearances

Cysts
On ultrasound examination cysts have:
1) Smooth walls
2) Sharp anterior and posterior borders
3) Black hypoechoic centres without internal echoes

Solid lesions
Solid lesions have internal echoes
Malignant tumours have:
1) Hypoechoic areas interspersed between brighter echoes
2) Irregular edges
3) Cast hypoechoic shadows
Benign tumours have:
1) Isoechoic or hypoechoic patterns
2) Smooth well defined borders
3) Cast no hypoechoic shadows