Laszlo K. Tabar MD, Presenter: Nothing to Disclose

1) Be familiar with the distribution of the mammographic signs of the breast cancer subtypes. 2) Be able to differentiate the malignant versus benign stellate and circular lesions by analyzing their mammographic features. 3) Be able to recognize the different histologic subtypes of breast cancer and know their incidence and prognosis. 4) Be able to differentiate between pathologic asymmetric densities and asymmetric fibroglandular tissue.

The mammographic image reflects the heterogenic histologic structure of the breast simplified into the four following basic patterns: 1) Stellate / spiculated tumors, 2) Architectural distortion 3) Circular or oval tumors 4) Calcifications with or without an associated tumor mass. A tumor mass without calcifications accounts for 64% of breast cancers seen on the mammogram. An additional 17% of breast cancers appear as a tumor mass with associated calcifications, emphasizing the importance of specifically searching for tumor masses to detect breast cancer at an earlier stage. The currently popular emphasis on detecting calcifications should not override the much more important objective of detecting subtle stellate and circular tumors on the mammogram. The stellate / spiculated tumors account for nearly half of all invasive breast cancers and have a typical mammographic appearance when 1 cm and larger, but tumors smaller than 5 mm in size tend to have a more nonspecific appearance, making their detection difficult. The radiologist needs to understand the radiologic appearance of the various types of normal breast tissue and how this is altered by small invasive breast cancers. Small circular / oval lesions form the second most important pattern of breast cancers, and although these tend to have a characteristic mammographic appearance when small, they may be easily indistinguishable from benign breast lesions. A strategy for evaluating tumors on the mammogram is presented, illustrated with mammographic, ultrasound, and both conventional and thick section histopathology images. The important pathologic tumor subtypes are also reviewed, complete with graphs showing incidence and prognosis, depending on tumor type, size, grade, and lymph node status. The life-saving importance of early detection of breast cancer through mammography is rigorously demonstrated.

Tabar, L, Masses, Asymmetries, and Architectural Distortion.  Radiological Society of North America 2005 Scientific Assembly and Annual Meeting, November 27 - December 2, 2005 ,Chicago IL. http://archive.rsna.org/2005/4404678.html