Image-guided or needle-localized open biopsy of mammographic malignant-appearing microcalcifications?

The evaluation and initial management of abnormalities detected on screening mammography have evolved substantially over the last decade. This study was designed to evaluate the most appropriate initial diagnostic biopsy technique for patients presenting with malignant-appearing microcalcifications on screening or diagnostic mammography.

An institutional review of a prospective database was performed to compare initial image-guided breast biopsy (IGBB) and needle-localized open biopsy (NLOB) in patients presenting with malignant-appearing microcalcifications. Patients with atypical hyperplasia (AH) or carcinoma in situ (CIS) were identified and reviewed separately. Measures of outcomes included the total number of procedures, time from initial biopsy to definitive treatment, charges, and percentages of patients who required both procedures.

A total of 17,121 patients underwent mammography from July 1994 to December 1996 at Gundersen Lutheran Medical Center. Indeterminate microcalcifications were found in 167 patients and were the reason for IGBB in 112 and NLOB in 55 patients. Histologic results included 81 patients (48%) with benign lesions, 25 (15%) with invasive cancers, and 61 (37%) having a proliferative finding including AH or CIS. Ductal CIS was present in 42 (72%) of the 61 proliferative lesions. Comparisons were made between the groups of patients with CIS or AH who underwent initial NLOB (n = 25) versus those having initial IGBB that was followed by a secondary NLOB (n = 25). The median elapsed time to definitive therapy was 20 days (range 0 to 336 days) for initial IGBB followed by NLOB and 7 days (range 0 to 79 days) for an initial NLOB performed for suspicious microcalcifications (p = 0.0367). The total number of procedures performed on each patient and total costs were also less for patients having an initial NLOB.

The time to definitive local therapy, the number of procedures, and overall charges were less for patients with AH or CIS having initial NLOB as opposed to initial IGBB. Careful initial evaluation of microcalcifications may identify some patients for whom an initial NLOB remains the most appropriate procedure. Such patients desiring breast-conserving therapy may benefit in terms of time to definitive treatment, total number of procedures performed, and cost if a careful NLOB is the initial procedure performed as a formal lumpectomy.