The basis for the analysis of microcalcifications is the detection of the same. This, in turn, depends on the mammography equipment used (c-view) and on the density of the glandular tissue. The next step is the analysis of the distribution and the shape of the microcalcifications. Secondary is the size, the density, and the number of microcalcifications. Grouped microcalcifications are not a domain of US, in our opinion. Microcalcifications are easier to detect on 2D than subtle lesions causing radial distortions; 3D is very helpful in detecting these lesions; many of these lesions represent small invasive cancers, and finding a small invasive cancer has a much higher benefit than finding a DCIS.

Fine linear branching casting-type calcifications and segmental distribution along the milk ducts → high grade in situ G3/G2, pleomorphic heterogeneous, crushed stone-like calcifications → characteristic of G2 in situ carcinoma, amorphous indistinct calcifications → G1 in situ carcinoma located in the terminal ductal lobular units. These intralobular calcifications lead to significant differential diagnostic difficulties with low specificity, due to their morphology being similar to that of the calcifications of benign changes (differential diagnosis – see above).

Typical findings in IDC are a dense spiculated or microlobulated mass, grouped associated microcalcifications in 30 %. It is the most common form (70 %) of invasive breast cancer; most women detect a lump themselves unless routinely screened; IDC occurs in all age groups (peak age 55–60 s), age < 40 years rare (consider familial cancer); hard and stiff lump; palpation often overestimate the size of the lesion; prognosis depends on lymph node status > tumor size > tumor grading—well, moderately, or poorly differentiated (G1 better than G2, G2 better than G3).

Morphologically, IDC is a very variable tumor (asymmetric density, distortion, circumscribed round or oval mass); compare with prior mammogram if possible and look for new or increased density, associated grouped microcalcifications (may be the only hint in breast density ACR III and IV), skin or nipple retraction (rare) due to often strong fibrotic component of the tumor. Caution – in dense breasts 50 % of IDCs are occult on mammography.

Surgical excision recommended (biopsy → surgery: histologic upgrade in 15–25 %); in premenopausal women the risk of developing breast cancer is (8–12 × higher or 1 % per year); consider screening of high-risk patients.

Often there is an incidental finding and search for other lesions in histologically proven LCIS. Often there is an incidential finding. On mammographic analysis there are amorphous calcifications, and, rarely, a mass with or without calcifications.

MRI recommended for assessing the extent of disease, spiculated lesions, isolated architectural distortions, sometimes multiple foci with interconnecting septal enhancement, rare isolated septal enhancement; can be false negative; look for axillary lymphadenopathy.

Invasive lobular carcinoma has the lowest detection rate of breast carcinomas; therefore, it is often diagnosed late; sensitivity on mammography is ~50–60 %; sensitivity on US is better, ~85–90 %. The entity accounts for 10–15 % of all breast cancers (often LCIS- or ALH-associated precursors); occurs at all ages, peak between 40 and 60 years; palpable thickening or palpable mass; tendency to multicentricity, multifocality, and bilaterality; prognosis equal to IDC.

Special type of IDC (controversial discussion), 5 % of all breast cancers (younger patients and those with BRCA gene), rapidly growing palpable soft mass, calcifications uncommon, tendency to multicentricity and bilaterality, triple negative, early recurrences but prognosis better than IDC (5 year survival 90 %.).

may be, in its typical form, difficult to distinguish from fibroadenoma; satellite lesions common; look for axillary lymph nodes.

oval – round or lobular circumscribed hypoechoic lesion; look for indistinct or microlobulated margins due to lymphocytic-infiltrative changes, hyperechogenic halo, posterior enhancement.

Nodule is less visible on 2D and 2D (synthetic). False spiculae due to superposition of blood vessel and fiber. 3D is very good for the evaluation of margins. Good example of why you need 3D even if you see it on 2D and 2D (synthetic); look for asymmetric density in retromammillary region.

Can arise from radial scars, can be stable for years or slowly growing, rare (2 %), all ages (mean 50 years), better prognosis than IDC, 95 % 5 year survival.

ill-defined, subtle distortion or stellate mass with prominent spiculae, sometimes one-view-only finding, associated with grouped microcalcifications in 50 % and associated with DCIS.