Presentation and Presenting Images
A 63-year-old female with a history of left breast cancer treated with segmentectomy and radiation therapy presents for routine screening mammography.
63.2 Key Images
63.2.1 Breast Tissue Density
The breasts are heterogeneously dense, which may obscure small masses.
63.2.2 Imaging Findings
There is a possible 1-cm architectural distortion (circle in ▶ Fig. 63.5 and ▶ Fig. 63.7) in the posterior depth of the right breast’s upper outer quadrant at the 11 o’clock location, 7 cm from the nipple. There is a postsurgical scar in the left breast denoted by a scar marker (arrow in ▶ Fig. 63.6 and ▶ Fig. 63.8). Clinical information regarding a prior procedure on the right breast would be helpful. The patient reports that she has not undergone any right breast procedures. Additional diagnostic mammography with possible ultrasound are recommended.
63.3 BI-RADS Classification and Action
Category 0: Mammography: Incomplete. Need additional imaging evaluation and/or prior mammograms for comparison.
63.4 Diagnostic Images
63.4.1 Imaging Findings
Slices from the digital breast tomosynthesis movies confirm architectural distortion (circle in ▶ Fig. 63.11 and ▶ Fig. 63.12) in the right breast at the 11 o’clock position in the posterior depth, 7 cm from the nipple.
Ultrasound shows a 1-cm hypoechoic area of architectural distortion that corresponds to the mammographic finding ( ▶ Fig. 63.13). This finding is suspicious and an ultrasound-guided biopsy was performed.
63.5 BI-RADS Classification and Action
Category 4B: Moderate suspicion for malignancy
63.6 Differential Diagnosis
Focal fibrosis: Focal fibrosis, also known as stromal fibrosis, has a variety of appearances.
Radial scar: Radial scars usually present as an area of architectural distortion.
Postprocedure changes: Postprocedure changes may present as areas of architectural distortion. The lack of prior procedures makes this an unlikely possibility.
63.7 Essential Facts
Although its prevalence on mammography is small compared with masses or calcifications, architectural distortion may be more challenging to diagnose due to its subtle and variable appearance.
Architectural distortion is a common finding in retrospective assessments of false-negative mammograms and may represent an early manifestation of breast cancer.
Focal fibrosis is characterized by the proliferation of the stromal connective tissue with obliteration of the mammary ducts and lobules.
Focal fibrosis has been called by many names, including stromal fibrosis, focal fibrous disease of the breast, fibrous mastopathy, fibrous tumor of the breast, and chronic indurative mastitis.
On mammography and ultrasound, the appearance of focal fibrosis is variable from benign-appearing to suspicious-appearing.
63.8 Management and Digital Breast Tomosynthesis Principles
Digital breast tomosynthesis (DBT) allows for improved visualization of architectural distortion over conventional mammography.
In this case, the finding was seen well only on the craniocaudal (CC) view on conventional mammography but on both views with DBT.
If the finding had been seen on only one view with DBT, its position in the orthogonal view could have been determined.
Tomosynthesis-directed stereotactic biopsy could have been performed rather than ultrasound-guided biopsy. Ultrasound-guided biopsy is more convenient for many patients given that the biopsy can be performed without compression and with the patient in a recumbent position.
63.9 Further Reading
 Gaur S, Dialani V, Slanetz PJ, Eisenberg RL. Architectural distortion of the breast. AJR Am J Roentgenol. 2013; 201(5): W662-W670PubMed
 Rangayyan RM, Banik S, Desautels JEL. Computer-aided detection of architectural distortion in prior mammograms of interval cancer. J Digit Imaging. 2010; 23(5): 611‐631 PubMed
 You JK, Kim E-K, Kwak JY, et al. Focal fibrosis of the breast diagnosed by a sonographically guided core biopsy of nonpalpable lesions: imaging findings and clinical relevance. J Ultrasound Med. 2005; 24(10): 1377‐1384 PubMed
Fig. 63.1 Right craniocaudal (RCC) mammogram.