Suspicious breast calcifications

Last revised by Daniel J Bell on 30 Jun 2021

Suspicious breast calcifications are calcifications within the breast that have a morphology and/or distribution on mammography indicating a significant probability of malignancy. These merit further workup and biopsy 1.

Radiographic features


Some calcifications may be more conspicuous on digital breast tomosynthesis rather than 2D mammography 2. The advent of digital mammography likely enhanced the screening detection of calcification-related breast cancers compared to analog film mammography 4.

On diagnostic evaluation, additional spot magnification views should be obtained to confirm the morphology and number of calcifications. 

Mammographic appearance

In general, suspicious calcifications tend to be smaller and less regular than typically benign calcifications 1,2.

The BI-RADS 5th edition lexicon includes four descriptors of suspicious calcification morphology on mammography, which are listed in order of increasing suspicion 1,3:

  • coarse heterogeneous: irregular, generally 0.5-1 mm
  • amorphous: indistinct and/or small ("powdery", "cloud", or "cottony"), such that another specific shape cannot be determined
  • fine pleomorphic: variable shape ("shards of glass" or "crushed stone"), generally <0.5 mm
  • fine linear or fine-linear branching: thin (<0.5 mm), linear, branching or irregularly arranged ("casting")

These can be combined with descriptors of calcification distribution (besides diffuse, which is almost always benign), which are listed in increasing order of suspicion 1:

  • regional: scattered in a larger volume (>2 cm in greatest linear dimension) of breast tissue and not in the expected ductal distribution
  • grouped: a cluster of at least 5 calcifications within 1 cm from each other, in an area at most 2 cm in greatest linear dimension
  • linear: calcifications arrayed in a line suggestive of deposition along ducts
  • segmental: calcium deposits in ducts and branches of a segment or lobe

In other words, for suspicious morphologies, a linear or segmental distribution more strongly increase the probability of malignancy than does a group.

Although not an inherently suspicious morphology, punctate calcifications can be suspicious if they are new, increased, or linear or segmental in distribution 1

Radiology report

Suspicious calcifications identified on screening mammography should be assessed BI-RADS 0 to indicate the patient should be recalled for additional views.

At diagnostic mammography, suspicious calcifications are categorized as BI-RADS 4. If there is a combination of findings that is highly suggestive of malignancy (e.g. fine linear and branching calcifications in segmental distribution, or microcalcifications associated with a spiculated mass), then a BI-RADS 5 assessment may be appropriate.

Amorphous calcifications are usually suspicious (BI-RADS 4) unless they are bilateral and diffuse and/or stable for many years. A single group of coarse heterogeneous, amorphous, or fine pleomorphic calcifications are moderately suspicious (BI-RADS 4B), whereas fine linear or fine-linear branching calcifications are highly suspicious (BI-RADS 4C) 1,4-9

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Cases and figures

  • Case 1: crushed stone, DCIS
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