Mammographic Images of Breast Cancer

  • Diffusely invasive carcinoma:
    • Has a mammographic appearance of:
      • Diffuse architectural distortion:
        • Usually involving a large area, often larger than a lobe:
          • With no central tumor mass and no calcifications
    • It sometimes has the appearance of a “spider’s web” as shown in Image
Mastectomy slice radiographs (a) and large format 3D histology image (b) showing concave contours similar to normal breast.
  • The diffusely infiltrating cancer:
    • Forms concave contours with the surrounding fat in a manner similar to normal fibroglandular tissue (Images Above)
  • The imaging findings of diffusely infiltrating breast cancer:
    • Are strikingly different from the imaging findings of breast cancers originating either from the terminal ductal lobular units (TDLUs) or the lactiferous ducts:
      • Suggesting that it may have a different site of origin
  • It has been recently proposed that diffusely infiltrating breast cancers:
    • May originate from mesenchymal stem cells (progenitors):
      • Through a complex process of both:
        • Epithelial-mesenchymal transformation and more frequently, mesenchymal-epithelial transformation
    • The clinical presentation is typically a:
      • Recently detected, extensive, firm lesion:
        • Often appearing as an interval cancer following a previous mammogram which was interpreted as normal
      • On clinical breast examination:
        • The cancer does not have a distinct tumor mass or focal skin retraction seen in other cancers:
          • But rather an indistinct “thickening” and eventually a shrinkage of the breast
        • In order to make the diagnosis before the development of a palpable mass and a decrease in size of the breast:
          • The radiologist and breast surgeon must have a high level of suspicion and a thorough knowledge of the underlying pathophysiology
  • The subgross (3D) histopathology images:
    • Show how growth of the mesenchymal tissue distorts the normal, harmonious connective tissue framework:
      • By causing nonuniform thickening of the fine sheets of connective tissue
  • The predominance of mesenchyme in the diffusely infiltrating breast malignancy:
    • Allows it to be imaged with greater sensitivity by ultrasound than by mammography
  • The thin sheets or veils of tissue reflect the ultrasound waves:
    • But are relatively easily penetrated by x-rays
  • The structural / architectural distortion, while difficult to detect mammographically:
    • Is readily detectable on 2-mm thick coronal sections of automated breast ultrasound
  • The hypoechoic changes:
    • Can also usually be seen on hand-held ultrasound
  • The growth pattern and cell type of diffusely invasive breast cancer is very similar to that of diffuse gastric carcinoma (linitis plastica):
    • Both of these diseases can be associated with a deleterious mutation in the CDH1 gene:
      • Which is located on chromosome 16q22 and codes for e-cadherin protein
  • References:
    • Hansford S, Kaurah P, Li-Chang H, Woo M, Senz J, Pinheiro H, et al. Hereditary diffuse gastric cancer syndrome: CDH1 mutations and beyond. JAMA Oncol. 2015;1(1):23-32.
    • Tot T. The diffuse type of invasive lobular carcinoma of the breast: morphology and prognosis. Virchows Arch. 2003;443(6):718-724.
    • Tot T. Diffuse invasive breast carcinoma of no special type. Virchows Arch. 2016;468(2):199-206.
Mediolateral oblique and craniocaudal projections

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