We retrospectively reviewed the charts of 1112 patients who underwent US-guided CNB of breast masses utilizing 14-gauge,
16-gauge,
or 18-gauge cutting needles.
The radiologists who performed the biopsies were faculty radiologists who had from 1 year to over 30 years of experience in breast imaging and US-guided procedures or radiology fellows operating under the supervision of breast imaging faculty members.
Either of two commercially available disposable biopsy devices (MaxCore [Bard Medical,
Covington,
GA,
USA] and Achieve [CareFusion,
San Diego,
CA,
USA]) with a similar needle throw (22 mm for MaxCore and 25 mm for Achieve) was used in each case.
Cases included in our study were those with surgical-pathological confirmation of the diagnosis,
those with a minimum of 2 years of imaging follow-up,
—and those in which malignant masses were diagnosed by CNB but the patients did not undergo surgery (e.g.,
patients with lymphoma,
breast metastases from an extramammary primary tumor,
breast cancers that had already metastasized,
and breast cancers that had responded completely to neoadjuvant chemotherapy and were no longer identified in the surgical specimen).
Rates of CNBs with inadequate samples and discordance with surgical pathology and imaging follow-up results were calculated for each needle gauge and compared using Fisher’s exact test.
The histopathological results of the CNBs and of the surgical specimens were classified into three categories: malignant,
high-risk,
and benign. Malignant lesions included ductal carcinoma in situ (DCIS),
all types of invasive carcinoma,
lymphoma,
and metastases from extramammary primary tumors. High-risk lesions included flat epithelial atypia,
atypical ductal hyperplasia,
lobular neoplasia (atypical lobular neoplasia or lobular carcinoma in situ),
radial scar (radial sclerosing lesion,
scleroelastotic lesion,
sclerosing papillary lesion,
or complex sclerosing lesion),
papillary lesions (benign or atypical),
and mucocele-like lesions [2].
All other lesions were classified as benign.
The CNB result was deemed concordant if it was in the same category (malignant,
high risk,
or benign) as the surgical-pathological or imaging follow-up result.