Test characteristics of core needle biopsy of palpable breast masses: A review of Philippine General Hospital out-patient cases from 1999 to 2001

ABSTRACT

Core needle biopsy (CNB) has been used increasingly as a diagnostic tool in evaluating mammary lesions. To determine the test characteristics of CNB, histopathologic review of palpable breast masses in 81 female patients (mean age 48 years, range 17-71 years) obtained by non-imaging-guided CNB at the Philippine General Hospital Out-Patient Department from January 1999 to March 2001 was compared with the reviewed results of the subsequent excision (excision biopsy, simple mastectomy and modified radical mastectomy) as the reference standard. Of the 81 cases, 62 (77 percent) were histologically confirmed as malignant and 19 (23 percent) were benign. Of the 81 CNBs, 22 (27 percent) were unsatisfactory biopsies. Evaluation of CNB test characteristics was based on the rest of the 59 "satisfactory" CNBs. Test characteristics were Sensitivity=82.2 percent, Specificity=92.2 percent, Accuracy=84.7 percent, Positive Predictive Value=97.4 percent, Negative Predictive Value=61.9 percent. The test characteristics were lower compared to previously reported values which were however largely based on image-guided CNBs. Specimen adequacy, operator differences in skills and expertise, and histopathologic interpretation error may account for the difference. (Author)