–     Benign

Dystrophic/Fat necrosis  Ccoarse, irregular, lucent-centered, "lava-like" [from surgery, biopsy, minor trauma, radiation therapy]

Secretory  Large, > 1 mm in diameter, rod-like, continuous +/- branching, bilateral, radiate from nipple in ductal distribution, age > 60 [plasma cell mastitis, duct ectasia]

Milk of calcium  Morphology changes with position: pleomorphic/fuzzy on CC, teacup-like on ML/MLO [from

calcium layering in microcysts]

Popcorn  Coarse, large, hyperdense [involuting fibroadenoma]

Skin  Round/punctate, on skin en face, same configuration on different views = "tattoo sign"

Rim/Eggshell  [Rim = oil cyst; Eggshell = calcified cyst wall]

Vascular  Linear/parallel tracks coursing along blood vessels

Suture  Linear/tubular +/- surgical knots

–     Intermediate

Coarse Heterogeneous  Irregular, conspicuous > 0.5mm, tend to coalesce but are smaller than dystrophic calcifications [DDx: fibroadenoma, fat necrosis, DCIS]

Amorphous  Small, hazy, indistinct, "powdery" [40% benign, 20% high-risk, 20% DCIS]

–     Suspicious

Fine Linear +/- Branching  Thin, linear/curvilinear, irregular; dot-dash pattern; appearance suggests fillings of the lumen of a duct; "casting"

Fine Pleomorphic  Varying  sizes and shapes, more conspicuous than amorphous calcifications [25-40% risk of malignancy]

(Smithuis 2008)