mammographic architectural distortion

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Breast architectural distortion is a descriptive term in breast imaging (mammography, ultrasound, and MRI) to indicate that the breast parenchyma is tethered or indented. The finding per se is not a mass.

Pathology

Architectural distortion is often due to a desmoplastic reaction in which there is focal disruption of the normal breast tissue pattern. There are several features that can be considered as part of architectural distortion :

contour abnormality
trabecular thickening
trabecular disorganization

Etiology

Many entities can cause architectural distortion .In practice, the most common are surgery and malignancy. It is considered the third most common appearance of breast cancer .

primary causes
- invasive breast cancer, including both invasive lobular carcinoma and invasive ductal carcinoma
- ductal carcinoma in situ
- radial scar/complex sclerosing lesion
- fat necrosis
- sclerosing adenosis
- fibromatosis
secondary causes
- postsurgical scars (most common)
- trauma
- infection

Radiographic features

Architectural distortion can be visually subtle. Compared to 2D mammography, digital breast tomosynthesis increases the sensitivity, confidence, and interobserver agreement in detection of architectural distortion . Tomosynthesis also helps localize the abnormality. Targeted ultrasound should then be performed to confirm the finding, but MRI is an alternative if no ultrasound correlate is found .

Mammography/US/MRI

Architectural distortion is characterized by a number of possible appearances :

radiating thin straight lines or spiculations
focal retraction, distortion, or straightening at the edge of the parenchyma
blurring of normal tissue planes such as the fat-fibroglandular junction
straightening or thickening of Cooper ligaments
compression of tissue around a mass

Radiology report

Architectural distortion can be reported as a standalone finding or be associated with (adjacent to) another finding, such as asymmetry, calcifications, or mass. In most cases, architectural distortion is a suspicious finding (BI-RADS 4) . The BI-RADS Atlas suggests that an ultrasound finding of architectural distortion thought to be due to postsurgical scar may be categorized as probably benign (BI-RADS 3), but there is sparse data supporting this approach .