The quality of the mammograms should be assessed, and if not optimal, repeat examinations may be ordered.

Mammograms of the right and left breasts are first placed back to back (mirror images) for comparable projections.

Lighting should be homogeneous, and adequate viewing conditions should be maintained. The mammograms are inspected carefully. The search is done systematically through similar areas in both breasts.

First, breast symmetry, size, general density, and glandular distribution are observed. Next, a search for masses, densities, calcifications, architectural distortions, and associated findings is performed.

Benign calcifications tend to have specific shapes: eggshell calcifications in cyst walls, tramlike in arterial walls, popcorn type in fibroadenomas, large and rodlike with possible branching in ectatic ducts, and small calcifications with a lucent center in the skin.

Associated findings are then taken into account. These include skin or nipple retraction, skin thickening (which may be focal or diffuse) especially with superficially positioned lesions, tethering of the pectoralis major may be seen with deeply positioned tumors, trabecular thickening, skin lesions, axillary adenopathy, and architectural distortion.

If previous examination results are available, their comparison is useful in assessing disease progress.

The lesion seen is located by using the views to either of the inner or outer or the lower or upper quadrants. It may also be central or retroareolar. The lesion can be described in a clock-shape position. The breast is viewed as the face of a clock with the patient facing the observer. The depth of the lesion is assigned to the anterior, middle, or posterior third of the breast.

Masses in adipose breasts are east to detect because of the high contrast between the mass and surrounding breast tissue. In dense glandular breasts, masses can be difficult to perceive because they may be partially obscured by glandular tissue.

A 'Mass' is a space occupying lesion seen in two different projections. If a potential mass is seen in only a single projection it should be called a 'Density' until its three-dimensionality is confirmed.

Circumscribed (well-defined or sharply-defined) margins: The margins are sharply demarcated with an abrupt transition between the lesion and the surrounding tissue. Without additional modifiers there is nothing to suggest infiltration.

Indistinct (ill defined) margins: The poor definition of the margins raises concern that there may be infiltration by the lesion and this is not likely due to superimposed normal breast tissue.

Spiculated Margins: The lesion is characterized by lines radiating from the margins of a mass.

The normal architecture is distorted with no definite mass visible. This includes spiculations radiating from a point, and focal retraction or distortion of the edge of the parenchyma. Architectural distortion can also be an associated finding.

This is a density that cannot be accurately described using the other shapes.

It is visible as asymmetry of tissue density with similar shape on two views, but completely lacking borders and the conspicuity of a true mass. It could represent an island of normal breast, but its lack of specific benign characteristics may warrant further evaluation.

Additional imaging may reveal a true mass or significant architectural distortion.

Due to confusion of the term mass with the term 'density' which describes attenuation characteristics of masses, the term 'density' has been replaced with 'asymmetry'.

A spiculate breast mass is the commonest mammographic appearance of invasive breast carcinoma

It consists of a central soft tissue tumor mass from the surface of which spicules extend into the surrounding breast tissue. The larger the tumor mass, the larger the spicules tend to be.

Invasive carcinoma: 95% of spiculate masses seen on mammography

Non invasive carcinoma

Complex sclerosing lesion/ radial scar

Surgical scar

Fibromatosis

Granular cell tumor

Characterized histologically by a fibroelastic centre surrounded by ducts and lobules arranged in a radiating fashion.

Areas of similar or atypical ductal hyperplasia are often found in the peripheral of CSLs.

Microcalicifications may be associated particularly in areas of epithelial hyperplasia.

Usually diagnosed with ease from the appropriate clinical history and physical examination revealing the position of scar corresponding to the spiculated lesion.

In cases of confusion may be confirmed by repeating the mammogram with skin markers placed on the scar.

Surgical scars often show a difference in size and shape on orthogonal views cause of their discoid shape.

They are histologically similar to abdominal desmoid tumors.

They are locally invasive but do not metastasize.

Most Ca greater than 1 cm can be reliably demonstrated by ultrasound.

Typical features are echo poor mass, with poorly defined margins and posterior acoustic shadowing.

There may be distortion of the surrounding parenchyma and a rim of increased reflectivity may be seen- tumor collar

BENIGN MALIGNANT

SHAPE Oval/ellipsoid Variable

ALIGNMENTWider than deep, aligned parallel to tissue planes

Deeper than wide

MARGINSSmooth/thin echogenic pseudocapsule with 2-3 gentle lobulations

Irregular or spiculated, echogenic halo

ECHOTEXTUREVariable to intense hyperechogenecity

Low levelMarkedhypoechogenecity

HOMOGENETY OF INTERNAL ECHOES Uniform Non uniform

LATERAL SHADOWING Present Absent

POSTERIOR EFFECTSMinimum attenuation/ posterior enhancement

Attenuation with obscured posterior margin

OTHER SIGNS

Calcification, microlobulation,Intraductalextension, infiltrarionacross tissue planes and increased echogenecity of surrounding fat

BI-RADS assessment categories can be summarized as follows:

Category 0 - Need additional imaging evaluation Category 1 - Negative Category 2 - Benign finding, noncancerous Category 3 - Probably benign finding, short-

interval follow-up suggested Category 4 - Suspicious abnormality, biopsy

considered Category 5 - Highly suggestive of malignancy,

appropriate action needed Category 0 is a temporary category that means

additional imaging is needed before assigning a permanent BI-RADS assessment category.

Left breast MLO view screening mammograms shows a spiculated mass in the posterior mid to upper breast