False negativity rate of ultrasonography with mammography in women with palpable breast lumps

Abstract

This study was performed to determine the false negativity rates of ultrasonography with mammography in the assessment of women with palpable breast lumps. The relevant data on 202 female patients aged above 14 years of age, who had presented to our institution with a breast lump, had been retrospectively reviewed from our hospital database. Out of these, 155 patients for whom mammography with sonography imaging (MSI) was done were included in the study population. It consisted of tissue-positive cases, tissue-negative cases, and false-negative MSI confirmed on pathology. All cancer cases and false-negative cases using MSI were identified. Cancer rates, false-negative rates, and negative predictive values were calculated based on MSI breast imaging reporting and BI-RADS categories. Among patients who had undergone MSI, 73.55 % (114/155) of patients had BI-RADS 1–2. Despite a benign result, 10.5% (12/114) of them had gone ahead with a tissue diagnosis, whereas BI-RADS 4 and 5 had a 100% biopsy rate (28/28, 4/4, respectively). Out of the seventeen cancers detected in toto, only one belonged to BI-RADS 1–2. The false-negative rate of MSI (i.e., BI-RADS 1–2) was found to be 1.75% (1/114). As none of the remaining cases had progressed into malignancy post-follow-up (Median: 9 months, Range: 2 – 13 months), The negative predictive value (NPV) and cancer rate were estimated to be 99.12% and 0.88% respectively. Therefore, low false negativity and high negative predictive value of mammography with ultrasonography imaging for breast lumps were established.