• Should be investigated carefully
  • Technique called Fremitus can be used to identify and confirm margins
    • Fremitus - refers to vibrations produced by phonation and felt through the chest wall during palpation; a technique used in conjunction with power doppler to identifiy the margins of a lesion
    • Have the patient hum
  • Benign lesions usually have smooth, rounded margins
  • Malignancies are aggressive and tend to grow through tissue via spiculation
    • Spiculation - finger-like extension of a malignant tumor; usually appears as a small line that radiates outward from the margin of a mass
  • Spiculated margins are the U/S finding with the highest positive predictive value of malignancy
    • Typically alternating hypoechoic and hyperechoic lines

The mass is irregular, hypoechoic and has an echogenic halo and spiculated margins (arrows).

Disruption of Breast Architecture

  • Benign tumors are usually slow growing and do not invade surrounding tissue
    • They tend to grow horizontally within the tissue planes, parallel to the chest wall
    • Large bening lesions may cause compression of adjacent tissue
      • Do not confuse this with infiltrating

  • Malignant Lesions tend to grow right through the normal breast tissue
    • As masses enlarge they may cause retraction of the nipple or dimpling of the skin as the spiculation pull on the Cooper's Ligaments


  • Benign
    • Rounded or oval shape is usually associated with benign lesions
    • Mild undulations in contour
    • Larger, rounded lobulation -- not exceeding 3 in number
  • Malignant
    • Sharp, angular margins are associated with malignancy
    • Microlobulations (1-2mm) -- smaller, sharper, numerous


  • Normal tissue planes of the breast are horizontally oriented
  • Benign lesions tend to grow within the normal tissue planes, long axis lying parallel to chest wall
  • Malignant lesions are able to grow through the connective tissue and may have a vertical orientation when imaging A/P
  • If a mass measures longer in the A/P dimension than in either sagittal or transverse it is described as "taller than wide"
    • Suspicious for malignancy

Internal Echo Pattern

  • Benign
    • Isoechoic with breast parenchyma or have echoes equivalent to or brighter than fat

  • Malignant
    • Hypoechoic
    • Weak internal echoes
    • Dense posterior shadowing - making lesion difficult to penetrate
    • Microcalcifications within mass

Attenuation Effects

  • Benign
    • Enhancement beind a lesion - usually indicates fluid
  • Malignant
    • Shadowing behind a lesion
    • Do not confuse with edge shadowing

Mobility, Compressibility, and Vascularity

  • Benign
    • Limited degree of mobility
    • May roll as they are palpated
  • Malignant
    • Fixed and Rigid

  • Malignant lesions are normally very hard and noncompressible

  • Essential element of study
  • Malignant masses will often demonstrate increased vascularity with the lesion
    • Often have a feeder vessel -- can be identified with careful evaluation
  • Check with power doppler to determine number of vessels feeding and also look for intratumoral vessels