Breast calcifications (an approach)

An approach to breast calcifications in terms of imaging evaluation and biopsy aims to distinguish benign from malignant etiologies. This article overviews a general approach to the evaluation of breast calcifications. The types and descriptors of calcifications are detailed separately: breast calcifications.

Radiographic appearance

Morphology

• suspicious
  • fine linear or fine-linear branching
  • fine pleomorphic
  • amorphous
  • coarse heterogeneous
• indeterminate
  • ​punctate
• typically benign
  • ​skin
  • vascular
  • coarse or "popcorn-like"
  • large rod-like
  • round
  • rim (historically "eggshell")
  • dystrophic
  • milk of calcium
  • suture

Distribution

• suspicious
  • segmental
  • linear
• indeterminate
  • grouped
  • ​regional
• ​​typically benign
  • ​diffuse

Size

Small calcifications (<200 μm in diameter) are mostly malignant.

Stability   

Calcifications stable for greater than 2 years can be considered benign.

Number

The greater the number of microcalcifications in a small area, the more suspicious for malignancy.

Management

Screening mammography

At screening mammography, comparison should be made with prior studies to establish benignity through long term stability (at least 2 years) if possible. Calcifications identified on screening mammography that do not clearly appear benign should be recalled (BI-RADS 0).

Diagnostic mammography

At diagnostic mammography, additional views with magnification should be performed to confirm the morphology and number of calcifications.

Short interval followup

An isolated group of punctate calcifications at baseline evaluation can be designated probably benign (BI-RADS 3), for which short interval followup mammography is appropriate ⁶.

Other types of calcifications may be categorized as probably benign (BI-RADS 3) if the radiologist has personal experience justifying a watchful waiting approach, but these approaches are not supported by substantial evidence ⁷:

• developing calcifications that are most likely, but are not definitely, vascular
• calcifications suggestive of early evolving fat necrosis

Ultrasound

For suspicious calcifications, a focused ultrasound is reasonable to evaluate for a mammographically occult abnormality such as a mass. Calcifications can sometimes be redemonstrated on ultrasound as well, providing another option for image-guided biopsy.

Biopsy

Core needle biopsy of suspicious calcifications should be performed (BI-RADS 4 or 5) with image guidance using the available modality that best demonstrated the findings, which often means stereotactic or digital breast tomosynthesis-guided biopsy ⁸. Specimen radiographs should be obtained to confirm adequate sampling of the calcifications. Especially in the case of ultrasound-guided or MRI-guided biopsy, a biopsy marker should be deposited so that the correct biopsy site can be confirmed on post-biopsy mammography.

If no calcifications are identified at histology, the entire paraffin block can be radiographed and further sections obtained if there are indeed calcifications present ⁹.