Benign Calcifications

Analysis of breast calcifications by an experienced mammographer will allow accurate diagnosis of characteristically benign calcifications. The various types are described below.

Benign Breast Tumor
Figure 3-14. Pseudocalcification. Talc powder in moles beneath breast mimics parenchymal calcification.

Skin Calcification and Pseudocalcification

Skin calcification is commonly related to sebaceous glands and appears as lucent, centered rings in a peripheral location (Figure 3-13A). Skin calcification may be punctate or irregular, and may appear to lie within the breast parenchyma on standard views. Therefore, a tangential view skin localization study (Figure 3-13B) may be necessary to prove a cutaneous location. Calcium in warts, moles, scars, and dermal lesions as well as pseudocalcifications due to tattoos, talc, deodorant, or film artifacts can be misleading (Figure 3-14).

Vascular Calcifications

Calcification caused by atherosclerosis in arterial walls is usually easy to recognize due to the typical continuous linear tubular pattern (Figure 3-15A). Early changes of short segment calcifications appearing as discontinuous deposits in one wall may have a granular or fine linear appearance that can arouse suspicion (Figure 3-15B). Magnification views in alternate projections will usually allow a correct diagnosis.

Calcium in Cysts

Thin, curvilinear calcifications defining the margin of a mass are seen with cyst wall calci

Tram Track Like Ductal Calcification
Figure 3-15. Vascular calcification. A, Typical tubular arterial calcification. B, Irregular linear calcification, due to incomplete arterial wall involvement, can appear suspicious.

fications. Intracystic calcium particles suspended in fluid, known as "milk of calcium," may appear in multiple tiny cysts or a single larger cyst. This diagnosis is best proven with a 90-degree lateral film showing a meniscus or teacup shape of layered calcium in a cyst (Figure 3-16). These calcifications may be difficult to see when viewed en face in the CC view.

ducts diffusely and often bilaterally. Large, tubular periductal calcifications can appear in plasma-cell mastitis (Figure 3-18). Increased density of the subareolar parenchyma may be found. These large, rod-like secretory calcifications are usually easily differentiated from malignant calcifications by their large size and greater length.

Fibroadenoma

Calcifications appear in fibroadenomas as a result of involution which may be due to myx-oid degeneration, hyalinization, or infarction. Early calcifications may occur in the periphery of the mass and progress to large, geographic areas of calcium the appearance of which has been compared to popcorn (Figure 3-17). Eventually, the soft-tissue component may be completely replaced by a dense conglomerate of calcifications. However, when this classic pattern is not followed, an involuted fibroade-noma may appear as fine pleomorphic calcifications without a visible mass and biopsy may be required for diagnosis.

Secretory Calcification

Inspissated ductal secretions in normal or dilated ducts may calcify to form solid, coarse, and linear ductal casts involving one or more

Fat Necrosis

Calcifications due to fat necrosis are often seen as fine-rim calcifications surrounding a lucent center, varying in size from a few millimeters to

Figure 3-16. Milk of calcium. Layered sedimented calcium in microcysts appears curvilinear or teacup-shaped on horizontal beam lateral film.
Rim Calcifications Breast

Figure 3-17. Fibroadenoma. A, Few early coarse peripheral calcifications. B, Classic popcorn calcification. C, Large dense calcification nearly replaces mass.

several centimeters. Small ring forms, usually < 5 mm in diameter, are often idiopathic (Figure 3-19A). Dystrophic calcifications deposited after trauma, hemorrhage, surgical biopsy, and radiation may appear as larger and less regular calcifications surrounding an oil cyst (Figure 3-19B). It is important to note that this type of calcium may appear several years after a lumpectomy and breast radiation. In its early stages, it can be difficult to differentiate from recurrent malignant calcifications.

Lobular Calcifications: Adenosis/Sclerosing Adenosis

Lobular calcifications form in the acini in association with such entities as adenosis, sclerosing adenosis, atypical lobular hyperplasia, and cystic hyperplasia. Characteristically, these calcifications are small, dense, and round (Figure 3-20A). If a lobule is distorted by surrounding sclerosis, the individual forms may be more irregular. The distribution of calcifications in adenosis and sclerosing adenosis is often bilateral, diffuse, and inhomogeneous due to variable involvement of individual lobules. These characteristic findings indicate a benign process. Alternatively, the calcifications can be more focal, presenting as unilateral loosely grouped calcifications, regional calcifications, or a solitary small cluster (Figure 3-20B). In these situations, careful analysis of the calcifications with magnification views may allow periodic follow-up, but biopsy will often be necessary to exclude carcinoma.

Malignant and Indeterminate Calcifications

Microcalcifications are present in as many as 50 percent of all breast cancers and in an even higher percentage of stage 0 and stage 1 breast cancers.16-18 The presence of clustered microcalcifications may be the only indication of early preinvasive malignancy. Mammographic

Figure 3-18. Secretory calcification. Large, solid rod-like and tubular calcifications appear in a ductal orientation.
Rim Calcification Breast
Figure 3-19. Fat necrosis. A, Dense round lucent-centered calcifications caused by idiopathic fat necrosis. B, Postoperative oil cysts with thin eggshell (white arrow) and course rim calcification (black arrow).

detection of microcalcifications in patients with DCIS accounts for this entity rising from a small percentage of lesions found at biopsy to the current rate of 20 to 40 percent for biopsies for clinically occult lesions.22 Stomper and colleagues,23 in a group of 100 patients with DCIS, reported that 84 percent of cases presented with microcalcifications, either alone (72%) or as calcifications associated with a soft-tissue density (12%).

Classic malignant calcifications are typically associated with comedo carcinoma but are also present in other histologic subtypes of DCIS. Characteristic malignant calcifications occur as fine, pleomorphic, linear, and branching calcifications (Figure 3-21) or multiple irregular granules forming castings arranged in a ductal distribution (Figure 3-22). The extent of involvement may vary from < 1 cm to an entire lobule or even a whole breast (Figure 3-23). Holland observed a significant discrepancy between the estimated mammographic and actual histopathologic extent of DCIS.24 This discrepancy is most pronounced for low grade DCIS. Mammography underestimates the histopathologic extent by 16 percent for high grade DCIS and 47 percent for low grade DCIS.24

Clustered irregular granular calcifications,

Suspicious Calcification
Figure 3-20. Lobular calcification. A, Punctate, round, scattered calcifications (were bilateral) due to adenosis. B, Small group of round clustered calcifications (arrow), likely acinar, in a dilated lobule.
Linear Branching Microcalcifications

Figure 3-21. Linear and branching calcifications typical of comedo type ductal carcinoma in situ.

calcifications (Figure 3-24), that may have the most similarity to benign forms of calcium and thus require the greatest scrutiny. Invasive breast cancer associated with DCIS involving lEr

Figure 3-21. Linear and branching calcifications typical of comedo type ductal carcinoma in situ.

not clearly ductal in distribution, or mixed forms of granular and casting calcifications, are a more common presentation of DCIS (65%) compared to the classic pure casting and linear forms (35%).23 These granular calcifications are seen more frequently in low-grade, noncomedo carcinoma, although there is enough overlap that one cannot reliably subtype DCIS based on the mammographic morphology. It is also this group, because of the variability of the granular tf i

Segmental Calcification Breast

Figure 3-23. Distribution of microcalcifications in ductal carcinoma in situ. A, focal (arrow); B, segmental; C, diffuse (whole breast).

Figure 3-22. Granular calcifications forming ductal casts (arrows) in comedo type ductal carcinoma in situ.

Figure 3-23. Distribution of microcalcifications in ductal carcinoma in situ. A, focal (arrow); B, segmental; C, diffuse (whole breast).

0 -1

Responses

  • austin grant
    When calcifications appear to lsyer on 90 degree lateral view?
    3 years ago
  • fikru
    Is fine pleomorphic calcifications sometimes associated with a fat necrosis?
    1 year ago

Post a comment