Round breast calcification

Round breast calcifications are a mammographic descriptor of typically benign breast calcifications characterized by a round shape. In the 5 edition BI-RADS lexicon, the morphologic descriptor encompasses punctate calcifications, but the latter term more specifically applies to such calcifications measuring <0.5 mm, while round calcifications can be ≥0.5 mm .

Pathology

Typically benign round calcifications are frequently formed in the acini of the terminal ductal lobular units.

Radiographic features

Round calcifications appear circular or oval in multiple projections, smoothly well defined, and homogeneously opaque. Microcalcifications should be evaluated with magnification views to confirm their morphology.

Radiology report

According to the BI-RADS atlas, round calcifications that are diffuse in distribution are benign (BI-RADS 2) .

A single group of round (including punctate) calcifications on a baseline diagnostic evaluation may be classified as probably benign (BI-RADS 3) . In the seminal series of 1,234 such calcifications, only 1 turned out to be associated with cancer .

If punctate calcifications are new, increasing, or linear or segmental in distribution, they are suspicious (BI-RADS 4) . They are also suspicious if they are adjacent to a known cancer.

Differential diagnosis

Other typically benign calcifications may appear round in shape but have other distinguishing features:

• rim calcification: lucent center, nongrouped, round or oval
• skin calcification: lucent center, grouped, polygonal but sometimes round, localize to the skin on tangential views
• milk of calcium: can be round and smudgy but changes shape on different projections