[Sonographical breast biopsy: how many core biopsy specimens are needed?]

To determine the optimum number of specimens of a sonographically guided core biopsy of the breast.

From January 2001 to April 2001, sonographically guided core biopsies (coaxial needle: 11 G; core needle: 12 G) were performed on 106 patients with 115 BI-RADS trade mark 4-5 lesions that had corresponding sonographic findings. Five specimens were obtained in anteroposterior direction parallel to the chest wall and each specimen examined histologically.

A total of 575 core biopsies produced 545 specimens (94.8 %), with no material obtained in 30 biopsies (5.2 %). The first and second specimen confirmed the diagnosis in 99 of 115 lesions (86 %), with subsequent specimens confirming the diagnosis in 87 % (3 rd specimen), 88 % (4 th specimen) and 82 % (5 th specimen). The additive accuracy of the five core breast specimens was 86 %, 96 %, 98 %, 99 % and 100 %. The possible volume of 78.9 mm 3 as determined by the sample notch of the core needle only furnished an average volume of 38.1 mm 3 (41.1 mm 3 for the 1 st, 40.1 mm 3 for the 2 nd, 37.5 mm 3 for the 3 rd, 36.7 mm 3 for the 4 th and 35.0 mm 3 for 5 th core specimen).

Sonographically guided core breast biopsy (coaxial needle: 11 G; core needle: 12 G) may require five passes to achieve a diagnostic accuracy of more than 99 %.