Minimally invasive ultrasound-guided biopsy a fine diagnostic for nonpalpable breast lesions

Breast lesions that physicians can’t feel by palpation are little match for fine-needle aspiration guided by ultrasound, although the procedure’s performance varies somewhat with the age of the patient and the BI-RADS category of the lesion.

That’s according to a study conducted at the Curie Institute in Paris and published online May 13 in the American Journal of Clinical Pathology.

Josep Farras Roca, MD, and colleagues assessed 2,601 nonpalpable breast lesions that were biopsied ultrasound-guided fine-needle aspiration (USFNA), a relatively gentle biopsy procedure, as performed by a radiologist-pathologist team.

The researchers based gold-standard diagnosis on surgery, core-needle biopsy or one-year imaging follow-up.

Analyzing the method’s diagnostic performance in different clinical and imaging subgroups, they found:

• USFNA’s sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were, respectively, 92.6 percent, 96.8 percent, 94.8 percent and 95.4 percent.
• The best PPV was achieved in BI-RADS categories 4C and 5. The best NPV was achieved in BI-RADS categories 2, 3 and 4A and in patients younger than 50.
• The BI-RADS categories, associated palpable cancer, mitotic count (indicating whether and/or how rapidly the tumor cells are dividing) and age (under 50 vs. 50 or older) were statistically independent factors between USFNA’s false-negative and true-positive results.

Ultrasound-guided fine-needle aspiration “is a robust diagnostic procedure in nonpalpable breast lesions,” the authors conclude. “Age and the BI-RADS category of the lesion are important factors determining its performance.”