Source: DGNews  |  Posted 3 years ago

By Maggie Schwarz

BALTIMORE, Md -- October 17, 2008 -- Use of Breast Imaging and Reporting Data System (BI-RADS) subcategories by radiologists can help improve the accuracy of breast cancer diagnoses, according to research presented here at the American Society for Clinical Pathology (ASCP) 2008 Annual Meeting.

Mary Ann Sanders, MD, PhD, University of Louisville School of Medicine, Louisville, Kentucky, and colleagues conducted their study to determine the diagnostic accuracy of BI-RADS subcategory 4 diagnosis of mammograms by radiologists. Dr. Sanders presented the results on October 16.

Mammograms can now be subcategorised according to American College of Radiology criteria. "Levels 1 to 3 are benign lesions, and level 5 will almost always turn out to be malignant. Level 4, however, will turn out to be malignant in 30% of cases," she explained.

She went on to describe BI-RADS subcategories A, B, and C in level 4. "A is suspicious and C is very suspicious but not classic for malignancy," she said.

Dr. Sanders and colleagues analysed 239 breast biopsies to determine whether that subcategory turned out to be accurate as seen on biopsy.

All of the stereotactic needle core biopsies were assigned a BI-RADS 4 on screening mammography, and of these, 191 were subcategorised to 4A, 4B, or 4C. Of 191, 49.2% were 4A, 38.2% were 4B, and 12.6% were 4C.

Of 24 BI-RADS 4C category cases, 71% were ductal carcinoma in situ. In contrast, 11% of 94 BI-RADS 4A and 21% of 73 4B cases were ductal carcinoma in situ. Without subcategorisation, carcinoma was diagnosed in 23% of 239 cases with BI-RADS 4.

"Very good correlation was found," concluded Dr. Sanders. She urged radiologists to include the subcategorisation in their diagnosis of mammograms.

"The Bi-RADS subcategorisation is a great tool that gives us history. It improves communication to the pathologist, which ultimately improves patient care," she emphasised.

[Presentation title: Clinical Implications of BI-RADS 4 Subcategory Breast Lesions Associated With Microcalcifications: A Radiology-Pathology Correlation Study. Abstract P649]