Conventional wisdom holds that DCIS consists of malignant cells that have not invaded other tissue, but László Tabár, MD, has identified subtypes that he thinks are actually invasive and merely mimic DCIS. Fragmented casting (as seen on the page 1 image) and "snakeskin-like" calcifications, appearing either alone or with a mass on the mammogram, are particularly menacing, he maintains.

At talks across the United States, Dr. Tabár, a pioneer in mammography education, demonstrates how state-of-the-art mammography, in combination with modern pathology techniques, is exposing the true nature of the many subtypes of breast cancer. A new understanding is emerging of the increasingly detected ductal carcinoma in situ (DCIS), which now accounts for more than one-fifth of all breast cancers in the United States.

"The combination [of mammography and advanced pathology techniques] will revolutionize breast cancer diagnosis," said Dr. Tabár, professor of radiology, University of Uppsala School of Medicine, Sweden.

Large-format pathology

Dr. Tabár is a strong advocate of subgross thick-section 3D histology techniques in combination with large-format pathology. The latter involves analysis of much bigger chunks than usual of biopsy tissue on large slides. Dr. Tabár maintains that these techniques enable better visualization of normal breast patterns, which vary enormously between patients, helping to reduce unnecessary callbacks for benign processes. They also make it possible to correlate mammography, 3D breast MRI, and 3D ultrasound images with pathology findings.

"Accurate measurement of the extent of DCIS has proven difficult with conventional pathologic techniques. MRI and 3D ultrasound create a renewed need for correlative pathology, accomplished with large-format breast pathology techniques," said Lee Tucker, MD, head of pathology and director of the breast care program at Carilion Breast Center, Roanoke, Virginia, a US test-bed facility for Dr. Tabár's theories.

Dr. Tabár considers conventional breast pathology outdated. Modern imaging techniques can demonstrate the entire organ on the film or monitor, while "comparative histology" shows only a 4- to 5-micron-thick, 1.5 × 1.5-cm piece of tissue. "The type of histologic examination used all over the US is an old-fashioned 200-year-old technique," he said.