-Original-

A New Method for Differentiating Benign and Malignant Pleomorphic Clustered Calcifications in Mammography

Mari Kikuchi^1,2, Hiroko Tsunoda¹, Tadashi Kaneshiro³, Osamu Takahashi⁴, Koyu Suzuki⁵, Hideko Yamauchi⁶, Taro Ichikawa² and Shin-ichiro Kumita⁷

¹Department of Radiology, St. Luke's International Hospital
²Department of Radiology, Nippon Medical School Musashi Kosugi Hospital
³Center for Minimally Invasive Treatment, Nippon Medical School Musashi Kosugi Hospital
⁴Department of General Internal Medicine, St. Luke's International Hospital
⁵Department of Pathology, St. Luke's International Hospital
⁶Department of Breast Surgery, St. Luke's International Hospital
⁷Department of Radiology, Nippon Medical School Hospital

Objective: Retrospective study to determine whether new mammography imaging characteristics can improve identification of an isolated cluster of coarse heterogeneous and fine pleomorphic calcifications as benign or malignant.
Materials and Methods: Institutional review board approval and informed consent were obtained. The study included 123 women (mean age, 50 years: age range, 34-79 years), in whom mammograms had found pleomorphic clustered calcifications, but without abnormal ultrasound findings and who underwent stereotactically-guided vaccum-assisted breast biopsy. Pleomorphic clustered calcifications were classified on the basis of 5 characteristics density, heterogeneity of density, number, heterogeneity of size, and distribution area size (DAS) of calcifications in the mediolateral oblique view (multiplication of the greatest length by the width of the total zone of clustered calcifications in mm²), and correlated with pathological findings.
Results: The chi-square test showed significant differences in whether a calcification was malignant or benign only in terms of DAS of calcification (p 0.009). There were significant differences in the association with malignancy of a DAS of 32- to 55 mm² (p=0.023, odds ratio=4.22), and the association more likely with a DAS of 56 mm² or larger (p=0.01, odds ratio=5.55) than with a DAS smaller than 18 mm² as a reference.
Conclusion: The DAS is a new and reliable variable for differentiating between benign and malignant pleomorphic clustered calcifications. The DAS improves diagnostic accuracy and is useful for determining whether to proceed with biopsies.

J Nippon Med Sch 2014; 81: 70-77

Keywords
mammography, pleomorphic clustered calcifications, stereotactically-guided vacuum-assisted breast biopsy

Correspondence to
Mari Kikuchi, MD, Ph.D, Department of Diagnostic Radiology, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan
markikuc@ncc.go.jp

Received, April 24, 2013
Accepted, July 29, 2013