Background: Ductal carcinoma in situ of the breast (DCIS) represents a challenge in mammographic screening due to its unknown progression into invasive cancer. The majority of the DCIS is detected due to signs of calcifications on the mammograms.
Purpose: To analyze the combinations of mammographic morphology and distribution of calcifications by Van Nuys nuclear grade (grade).
Material and methods: A total of 217 DCIS diagnosed in women aged 50-69 years old who participated in the Norwegian Breast Cancer Screening Program in the period November 1995 to December 2007 were reviewed by four breast imaging specialists. The mammograms were classified according to the morphology and distribution of the calcifications, using BI-RADS nomenclature. Chi square test was used to compare the groups of morphology and distribution by grade.
Results: Calcifications were identified in 93% (202/217) of the cases, 15% (30/202) as grade 1 and 74% (149/202) as grade 3. Fine pleomorphic calcifications were seen in 38% (77/202) of the lesions and fine linear and fine linear branching in 31% (62/202). Sixty-nine percent (53/77) of the fine pleomorphic and 84% (52/62) of the fine linear and fine linear branching calcifications were high grade lesions. Grouped distribution was seen in about half of all the cases (104/202). Among the high grade lesions with fine pleomorphic or fine linear and fine linear branching calcifications, 75% (40/53) and 69% (36/52), respectively, had grouped or segmental distribution.
Conclusion: DCIS presented overlapping groups of morphology and distribution of calcification by grade, but fine pleomorphic and fine linear and fine linear branching calcifications with grouped and segmental distributions were associated with high grade DCIS. Seeking for further knowledge that allows separation of non-high grade from high grade DCIS has to continue to improve the quality of mammographic screening.