Mammogram: focal asymmetry

Case contribution: Dr Radhiana Hassan


  • A 38 years old lady
  • Presented with left breast lump for few weeks
  • Mother had breast cancer at 6o years old
  • Married and nulliparous
Bilateral mammogram in MLO views
Bilateral mammogram in CC views

Mammogram findings:

  • Mammogram showed bilateral dense breasts, BIRADS C parenchymal density.
  • A focal density seen at the left upper outer region.
  • No obvious mass lesion is seen.
  • No suspicious clustered microcalcification.
  • No stromal distortion.
Ultrasound of left breast

Ultrasound findings:

  • A multilobulated lesion at Lt2H with irregular finger-like projection.
  • It is measuring about 17x13x11 mm.
  • There is associated posterior shadowing.
  • Presence of penetrating vessels seen.

Progress of patient:

  • Biopsy revealed invasive carcinoma
  • Mastectomy done in another hospital
  • Subsequently had chemotherapy

Discussion: Focal asymmetry on mammography

  • A focal asymmetric densities are frequently encountered at screening and diagnostic mammography.
  • These findings are significant because they may indicate a neoplasm, especially if an associated palpable mass is present.
  • A focal asymmetric density is defined as density seen on two mammographic views but cannot be accurately identified as a true mass.
  • They lack the convex borders of masses and are often interspersed with fat.
  • They also lack the radiating lines or tissue retraction of architectural distortion (AD) and the tubular branching appearance of a dilated duct.
  • Although a focal asymmetric density may represent normal breast tissue, further evaluation is often warranted to exclude a true mass or architectural distortion.
  • To assess the shape and margins of a potential lesion, a spot compression view is obtained.┬áIf a density is clearly evident on two views but appears less dense or less prominent on the spot compression view, one should not assume that it is not a true lesion: Spot compression displaces the normal tissue away and may make a true lesion appear less dense
  • US can also provide valuable information. The presence of a mass at US, particularly a hypoechoic solid mass or focal shadowing, raises suspicion for malignancy and definitely warrants biopsy. US can also demonstrate a cyst within a focal density that might prompt routine follow-up
  • Causes of focal asymmetry include normal variation, post trauma, post surgery, sclerosing lobular hyperplasia, diabetic mastopathy and breast cancer



Author: radhianahassan