Biopsy Appropriate for Amorphous Calcifications

WASHINGTON—A new study indicates that amorphous breast calcifications, unless clearly benign, should be considered suspicious lesions and should be stereotactically biopsied, said Wendie Berg, MD, PhD, associate professor of radiology and director of the Division of Breast Imaging, University of Maryland.

Improved imaging technology is leading to increased detection of amorphous calcifications (which appear subtle and powdery on film), but consensus has been lacking about how dangerous they are, Dr. Berg said at the 100th annual meeting of the American Roentgen Ray Society (ARRS).

Although evidence indicates that about 2% of these lesions might be malignant, researchers have suspected that the proportion is actually much higher, Dr. Berg said. Some clinicians have biopsied the calcifications and some have monitored them without biopsy, resulting in delayed diagnosis for some malignancies, she said.

“It never has been really clear,” she said. “Rather than sit on the fence, we wanted to determine the outcomes of patients with these lesions.”

From July 1995 through March 2000, Dr. Berg and her colleagues recommended biopsy for all clustered amorphous calcifications seen mammographically that were not clearly stable for at least 5 years.

Over the study period, 150 lesions in 132 women were characterized as amorphous calcifications and were biopsied, Dr. Berg said. Of the biopsies, 113 were performed stereotactically.

Overall, of the 150 lesions, 30 proved cancerous—a malignancy rate of 20%. Twenty-seven were ductal carcinoma in situ (DCIS), and three were low-grade invasive and intraductal carcinoma.

Another 30 lesions were found to be high-risk abnormalities. These included 21 atypical ductal hyperplasia, eight atypical lobular hyperplasia, and one lobular carcinoma in situ.

Sixteen lesions biopsied stereotactically yielded atypical ductal hyperplasia, a marker signifying a 10% to 20% chance of cancer nearby. Of these, two proved to have DCIS.

Eight lesions biopsied stereotactically yielded atypical lobular hyperplasia, signifying the possibility of cancer somewhere in the breast, and one of these was indeed a marker for DCIS, Dr. Berg reported.

“Such calcifications can be appropriately classified as suspicious,” she said. “I think this is pretty clear evidence we should be recommending biopsy for them. If you take care of these things now, it’ll mean a lot less trouble down the road.”

Dr. Berg’s team also analyzed the lesions by family history. Of 96 lesions in patients with no known family history of breast cancer, 16 (17%) were malignant. Of 12 lesions in patients with a family history, one (.08%) was malignant. These findings are significant, she said, because radiologists may be more likely to biopsy patients with a family history of the disease or other risk factors.