General Overview of Breast microcalcifications and indications of breast cancer malignancy

Breast calcifications, (small calcium deposits in breast soft tissue), are extremely common in women and almost always associated with a benign breast condition unrelated to cancer. They appears as white dots on a mammogram, and are not a cause of concern. Microcalcifications are also basically calcium deposits, but they are much smaller and much less common. Microcalcification tends to be the result of a genetic mutations somewhere in the breast tissue, but they can still be due to other conditions. The size, distribution, form, and density of microcalcifications are thought to give clues as to the potentially malignant nature of their origin.

 

microcalcifications on breast tissue

 

Classifications of microcalcifications according to form, size, density, and distribution.

In terms of Form, microcalcifications come in many shapes. They can be round, linear, coarse, granular (fine), monomorphic (all the same basic shape), or pleomorphic (many different shapes), or clustered.

In Size, microcalfications are described as either large or small, or when in clusters whether the sizes of microcalcifications are homogeneous or not. The Density of microcalcifications may be high, low, or variable. And if in a cluster, the homogeneous or non-homogeneous nature of the density is noted.

The Distribution refers to the overall placements of the microcalcifications within the breast image. Microcalfications can be in single clusters or multifocal, unilateral or bilateral, diffuse, segmental, linear, or regional.

 

breast tissue microcalcifications X-ray

 

Best indicators for the evaluation of microcalcifications: benign, suspicious, malignant.

So many different factors are taken into acount when deciding if a potential lesion is malignant or not. Microcalcifications are usually considered a very early screening indicator which may or may not be accompanied by suspicious histological findings, when requested. When evaluating microcalcifications, if there are combinations of findings that tend to lead to the same outcome ( benign or malignant), it is generally true that those predictions carry even more weight.

It can be said that as a general rule, when the microcalcifications are distributed in diffuse or bilateral arrangments in the acini, or with a round or punctate shape, or scattered in dense breast tissue, the situation is usually benign.

However, if the microcalcifications are in a branching or linear pattern and with irregular borders, or with variable density, or distributed in a segmental or haphazard way, this is highly suspicious of ductal carcinoma in situ, or malignancy in other words.

Sometimes the nature of microcalcifications can only be described as 'suspicious' requiring a biopsy to find out more predictive information. When the distribution is linear and the form of the microcalcifications are either round, oval, punctate, or amorphous, this is suspicious. A variable density of distributions (closely packed over here, widely spaced over there) is also considered to be suspicious but not definitive.

 

Other benign Breast Calcifications (not related to breast cancer)

Calcifications are common in the breast, and regardless of the cause they will appear on the mammogram. An experienced radiologist can quickly tell the difference from benign calcifications and those associated with breast carcinoma, however.

Epidermal and dermal (outer and inner skin layers) breast calcifications can take the form of moles with crevices. Also, sweat glands often develop round or oval, lucent-centered calcifications. Dermal breast calcifications are very common.

Vascular calcifications (emanating from blood vessels) may also develop in the breast. Typically they are linear, and when they originate in arteries they appear in a parallel 'tram track'-like formation. In very rare instances, vascular calcifications can arise from venous (in the veins) calcification in Mondor's disease.

Dystrophic calcifications are brownish, and are essentially 'scars' or rather calcium deposits accumlating in scar tissue. They tend to be dense, coarse, large, and irrebularly shaped, and develop in stromal tissues. (supporting, fibrous tissues). Dystrophic calcifications in the breast can result from many sources, including hematoma, fibrooadenoma, abscess, or may form in the fibrous capsules around implants. They can also appear post-surgery or post-radiation, or due to fat necrosis.

 

breast benign microcalcifications

Benign Ductal calcifications

Sometimes large, diffuse, bilateral, and 'rod-like' calcifications can appear in breast ducts, completely unrelated to cancer, which are usually the result of a secretory disease. These would include periductal mastitis, or plasma cell mastitis. ( Plasma cell mastitis is misnamed, and has nothing to do with plasma cells; it is really just inflammation following a bacterial infection.)

Benign lobular calcifications

Lobular carcinoma is much less common than ductal carcinoma to begin with, so any curious calcification in the breast lobules is very unlikely to be something serious. Benign lobular calcifications commonly appear round in shape, with a relatively high density. They typically have well-defined or pearl-like contours, and have smooth borders. If the lumen of acini are small, they often appear punctate (with little spots on them).

Sometimes benign lobular calcifications that are 'egg' shaped or rim-like develop in oil cysts, and teacup or meniscus-like shapes can develop in microcysts. The shape of lobular calcification depends to a certain extent upon the 'view' or angle of the X-ray. In a CC (Cranio-Caudal) view the lobular calcifications often appear round and smudgy, and scattered bilaterally.

Surgical sutures and parasites can be mistaken for breast calcifications

It's hard to believe, but occasionally surgical sutures (stiches) are mistaken for breast calcifications. This sometimes happens with inexperienced radiologists, or in a team setting where different individuals perform the clinical exam and the mammogram, but fail to communicate.

Parasites are so uncommon in western, industrialized nations that clinicians sometimes fail to consider them as a possibility, but in parts of Asia and Africa, they are not at all uncommon. Breast parasites might include filariasis, onechocerciasis, and loiasis (Loa Loa). Trichinosis is another nasty parasite that can sometimes take hold in the pectoral muscle. So, what may appear to be sinuous and linear calcifications are actually very small 'worms'. Typically, parasitic infections are treated with medications that attack the eggs, so eventually the parasites die off. This can take several weeks, however.

References

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Copyright Steven B. Halls, MD Last edited 01-December-2010

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