Presentation and Presenting Images
A 43-year-old female with a history of an abnormal mammogram performed at an outside institution presents for diagnostic mammographic evaluation.
74.2 Key Images
74.2.1 Breast Tissue Density
The breasts are heterogeneously dense, which may obscure small masses.
74.2.2 Imaging Findings
The imaging of the right breast is normal (not shown). The prior study performed at the outside institution is unavailable (not shown). The left breast demonstrates a 1.5-cm group of pleomorphic calcifications with a linear distribution at the 2 to 3 o’clock location in middle depth, 5 cm from the nipple ( ▶ Fig. 74.7, ▶ Fig. 74.8, ▶ Fig. 74.9, ▶ Fig. 74.11, and ▶ Fig. 74.12). Due to patient anxiety, only lateromedial (LM) digital breast tomosynthesis (DBT) was then performed and it demonstrated possible architectural distortion associated with the pleomorphic calcifications ( ▶ Fig. 74.10). Lymph nodes (arrow) are incompletely visualized on the mediolateral oblique (MLO) view ( ▶ Fig. 74.8).
74.3 BI-RADS Classification and Action
Category 5: Highly suggestive of malignancy
74.4 Differential Diagnosis
In situ and invasive ductal carcinoma: The combination of calcifications and architectural distortion is concerning for in situ and invasive ductal carcinoma. The incompletely visualized lymph nodes raise concern for invasive disease.
In situ carcinoma (DCIS): Although most commonly presenting as calcifications, DCIS may present as a mass with calcifications.
Fat necrosis: Fat necrosis has many appearances that overlap with the appearance of malignancy.
74.5 Essential Facts
ACR BI-RADS (Breast Imaging Reporting and Data System) Atlas, 5th edition, describes architectural distortion as distortion of the normal architecture of the breast with no discernible mass.
The differential diagnosis of architectural distortion includes both benign and malignant entities. The differential diagnosis of architectural distortion with associated calcifications also includes both benign and malignant entities.
In this case the suspicious calcifications, but not the architectural distortion, were identified on the conventional mammogram. The architectural distortion was unmasked at the time of DBT imaging. Identifying the architectural distortion increases the diagnostic suspicion for invasive malignancy in this case and leads to an upgrade of the BIRADS classification.
74.6 Management and Digital Breast Tomosynthesis Principles
DBT is excellent for identifying and characterizing findings other than calcifications. It is less effective than conventional mammography for identifying and characterizing calcifications.
Magnification views are vital to completely assess the morphology of calcifications. DBT cannot perform magnification views. The tomosynthesis system must support both mammographic imaging and tomosynthesis imaging.
With early tomosynthesis systems, large calcifications could cause considerable artifacts. Newer systems have software that reduce artifacts. These calcifications are very small and would not cause a significant artifact.
74.7 Further Reading
 Gaur S, Dialani V, Slanetz PJ, Eisenberg RL. Architectural distortion of the breast. AJR Am J Roentgenol. 2013; 201(5): W662-W670PubMed
 Sickles EA, D’Orsi CJ, Bassett LW, et al. ACR BI-RADS Mammography. In: ACR BI-RADS® Atlas, 5th edition. Reston, VA: American College of Radiology; 2013.
 Spangler ML, Zuley ML, Sumkin JH, et al. Detection and classification of calcifications on digital breast tomosynthesis and 2D digital mammography: a comparison. AJR Am J Roentgenol. 2011; 196(2): 320‐324 PubMed
Fig. 74.1 Left craniocaudal (LLC) mammogram.