Objective: The purpose of this study was to determine retrospectively the frequency and causes of false-negative diagnoses of lesions evaluated with percutaneous stereotactic biopsy performed with vacuum-assisted probes with the patient prone on a biopsy table.
Materials and methods: The records of 1,152 women (median age, 55 years; range, 31-94 years) with 1,280 lesions consecutively biopsied with 14-gauge (n = 159) or 11-gauge (n = 1,121) vacuum probes were reviewed retrospectively. The histologic diagnoses were malignant (n = 489), high-risk (n = 117), and benign (n = 674) lesions. Benign lesions were evaluated with repeated biopsy (n = 46) or mammographic follow-up for 24 months or longer (n = 506) or less than 24 months (n = 57). In 65 cases (10% of all benign lesions), follow-up was not performed. Fisher's exact tests were used to correlate patient, mammographic, and biopsy variables with false-negative diagnoses.
Results: Of 508 lesions with a final diagnosis of malignancy, the initial needle biopsy diagnosis was malignant (n = 489), high-risk (n = 14), or benign (n = 5) lesion. The five false-negative diagnoses were related to gauge of the biopsy probe and specimen radiographic findings regarding calcifications but were not related to lesion type. False-negative diagnoses were made in 4.4% (three of 68) of cases in which 14-gauge vacuum biopsy was performed and in 0.45% (two of 440) of cases in which 11-gauge vacuum biopsy was performed (p = 0.019). False-negative diagnoses were made in 25% (one of four) of cases in which specimen radiographs showed no calcifications and 0.67% (two of 300) of cases in which they did show calcifications (p = 0.0390). False-negative diagnoses were made in 1.2% (three of 248) of cases of calcification lesions and 0.8% (two of 260) of cases of mass lesions (p = 0.679).
Conclusion: False-negative findings at stereotactic biopsy were least common with 11-gauge probes and were similar in frequency for calcifications and masses.