The mammography system is a low-dose mammography technique that can clearly show all layers of breast tissue and can detect breast hyperplasia, and the mammography system is characterized by clear imaging, easy and quick inspection, and low radiation exposure. It can accurately determine and identify the calcification points of breast lesions that cannot be identified by color ultrasound, which is known as the “gold standard” of international breast disease examination.
With the improvement of living standards and the promotion of women’s breast diseases, more women no longer have the mentality of going to the doctor only after finding breast diseases, but pay more and more attention to the regular examination and maintenance of the breast, and the mammography palladium examination system is favored by the majority of women friends because of its many examination advantages.
I. Common signs
1. Lumps.
An occupying lesion with bulging edges that can be seen in two different projection locations is the most important edge sign to determine the nature of the lump. Suspected masses seen in only one projection position are called “dense shadow”; those without obvious bulging edges are called “asymmetric”.
Small lobes, infiltrates and asteroidal margins are signs of malignancy. It is sometimes difficult to distinguish between blurred margins and infiltrates, but it is very important, as the former are mostly benign changes, while the latter are malignant signs, and local compression photography and flattening techniques are helpful in identifying marginal signs.
Density is described as high, isodense, low (excluding fatty density) and fatty density compared to the mass and its surrounding breast tissue of the same volume. Most breast cancers are high or equal density; very few breast cancers can be low density; breast cancers do not contain fat density and fat density is a benign manifestation.
2.Calcification.
Benign calcifications are often larger than malignant calcifications, showing rougher calcifications or round calcifications with clear edges. Malignant calcifications are often smaller and require magnification to help show. The calcifications are described in terms of both morphology and distribution. Benign calcifications may not be depicted, but they need to be described when they may be misinterpreted by another physician.
The morphology is divided into typical benign calcifications, intermediate calcifications (suspicious calcifications), and calcifications of high malignant potential.
The distribution of calcifications is often helpful in suggesting the pathological type of breast lesion and includes the following five types of distribution
Diffuse or scattered distribution refers to calcifications that are randomly dispersed throughout the breast; punctate and pleomorphic calcifications distributed in this way are mostly benign changes, often bilateral.
Regional distribution refers to calcifications that are distributed over a larger area (>2 cm × 2 cm × 2 cm) but cannot be depicted by a duct-like distribution, often exceeding a quadrant, and the nature of this calcification distribution needs to be considered in conjunction with the morphology.
Segment-like distribution often suggests that the lesion originates from one duct and its branches, or it may occur as a multifocal carcinoma on one lobe or one segmental lobe. Although benign secretory lesions may also have segment-like distribution of calcification, if the morphology of calcification is not characteristically benign, it is first considered as malignant calcification.
3.Structural distortion.
It is a distortion of normal structures without a clear mass visible, including radiolucent shadowing and focal constriction emanating from a point, or distortion at the edges of the parenchyma. Structural distortion can also be a concomitant sign of a mass, asymmetric densities, or calcifications. In the absence of a local history of surgery or trauma, structural distortion may be a sign of malignant or radiolucent scarring and should be referred for clinical excisional biopsy.
II. Special Signs
1. Asymmetric tubular structures/single dilated ducts.
Tubular or branch-like structures may represent dilated or thickened ducts. It is of little significance if not accompanied by other suspicious clinical or imaging signs.
2. Intramammary lymph nodes.
The typical presentation is kidney-shaped, with visible translucent cuts due to fat in the lymph node portal, often less than 1 cm. when the lymph nodes are large, but most of them are replaced by fat, the change is still benign. It can be multiple, or a single lymph node may look like multiple round nodal shadows due to significant fat replacement. The correct diagnosis can be made for characteristic changes in the upper outer part of the breast. Occasionally, they may also appear in other areas.
3. Mass asymmetry.
Comparison with contralateral breast tissue is necessary to make a determination, and is more extensive to at least one quadrant. Includes a larger breast tissue that is denser than normal breast tissue or has more pronounced ducts visible, no focal mass formation, no structural distortion, and no accompanying calcifications. Often represents a normal variant or is the result of replacement hormone therapy. However, when coincident with clinically palpable asymmetry, it may have clinical significance.
4. Focal asymmetry.
A dense change that cannot be accurately described by other shapes. It is shown in both projection locations, but lacks the marginal changes characteristic of a true mass and is less extensive than a mass asymmetry. It may represent a normal breast island, especially when it contains fat. However, because it lacks characteristic benign signs, it often requires further examination, which may reveal a true mass or significant structural distortion changes.
III. Combined signs
Often combined with a mass or calcified sign, or as a separate change without other abnormal signs. These include skin indentation, nipple depression, skin thickening, trabecular thickening, skin lesions projected in the breast tissue, axillary lymph node enlargement, structural distortion, and calcification.
Overall assessment
I. The assessment is incomplete
Grade 0: Additional imaging is needed for further evaluation or comparison with the anterior film. Often applied in census situations and rarely used after complete imaging and comparison with the anterior film. Other imaging methods recommended include localized compression photography, magnification photography, special projection body photography, and ultrasound.
Second, the assessment is complete
1, Grade 1: Negative. No abnormal findings.
2.Grade 2: Benign findings. These include calcified fibroadenomas, multiple secretory calcifications, fat-containing lesions (lipid cysts, lipomas, ductal cysts and mixed density mismatched tumors), intramammary lymph nodes, vascular calcifications, implants, structural distortions with a history of surgery, etc. However, in general there are no x-ray signs of malignancy.
Grade 3 and 3: Probably benign findings, with short-term follow-up recommended. There is a high probability of benignity and the expectation is that this lesion will stabilize or shrink during short-term (less than 1 year, usually 6 months) follow-up to confirm the judgment. The malignancy rate at this level is generally less than 2%. The three signs of a well-defined mass without calcification, focal asymmetry, and clustered round or/and punctate calcification are considered to have a high likelihood of benign changes. For this level of management, a short-term follow-up of radiographs (6 months), followed by 6 months and 12 months to 2 years or more of stability was used to confirm his determination. 2 or 3 years of stability allowed a grade 2 reading (benign) from the original grade 3 reading (probably benign). This grade is used after a complete imaging evaluation and is generally not recommended for initial screening; it is also inappropriate for the evaluation of clinically significant masses; for a possibly benign lesion that increases in size during follow-up, a biopsy should be recommended rather than continued follow-up.
Grade 4 and 4: suspicious abnormalities to be considered for biopsy. This level includes a large group of lesions requiring clinical intervention. Such lesions do not have characteristic morphologic changes of breast cancer but have the possibility of malignancy, with an overall malignancy rate of about 30%. It is further divided into 4A, 4B, and 4C, where clinicians and patients can make the final decision on the management of the lesion according to its different malignant potential.
Grade 5 and 5: Highly suspicious of malignancy and clinically appropriate measures should be taken (almost certain malignancy). This category of lesions has a high likelihood of malignancy. The likelihood of detecting malignancy is greater than or equal to 95%. High-density masses with irregularly shaped stellate margins, segmental and linear distribution of fine linear and branching calcifications, and irregularly shaped stellate marginal masses with polymorphic calcifications should all be classified in this grade.
Grade 6 and 6: Biopsy has confirmed malignancy and appropriate measures should be taken. This grading is used in the imaging evaluation of biopsy-proven malignancy but not yet treated. The main purpose is to evaluate imaging changes after prior biopsy or to monitor imaging changes from neoadjuvant chemotherapy prior to surgery.