The impact of image guided needle biopsy on the outcome of mammographically detected indeterminate microcalcification.

A study was carried out to examine the impact of development in image guided needle biopsy on the outcome of mammographically detected indeterminate microcalcification. Between 01.04.1991 and 31.03.2001, the South East London Breast Screening Programme detected 392 cases of indeterminate microcalcificaton. Histological diagnosis was obtained using open biopsy, fine needle aspiration cytology (FNAC), 18/14 G wide bore needle core biopsy (WBNCB) and 11 G vacuum assisted core biopsy (VACB). The study period group was divided into two. Group A (between 01.04.1991 and 31.03.1996) and group B (between 01.04.1996 and 31.03.2001). There was a significant reduction in the benign open biopsy rate in group B compared to group A (25% vs. 51%) (P=0.0001). Of the malignant cases, there is a higher percentage of ductal carcinoma in situ (DCIS) in group B compared to group A (77% vs. 62%). In conclusion, the implementation of more effective methods of image guided biopsy has led to a 50% reduction in benign open biopsies for indeterminate microcalcification and to an increase in the detection of DCIS.