Positive predictive value of breast cancer in the lesions categorized as BI-RADS category 5

To determine positive predictive value (PPV) of the breast imaging reporting and data systems (BI-RADS) category 5 mammogram and ultrasound (US) in the diagnosis of breast cancer in the study center and correlation between clinical, mammographic and US findings, and breast cancer.

Four hundred and ninety seven patients with BI-RADS category 5 who underwent mammograms and US at the Breast diagnostic center, Ramathibodi Hospital from January, 1, 2002 to December 31, 2004 were enrolled into the present study. Selected clinical information, mammographic and US findings, and histopathological diagnosis were retrospectively reviewed.

Breast cancer was found in 467 of 497 patients, giving a PPV of 94%. Invasive ductal carcinoma was the most common malignancy (89.5%). Fibrocystic change was the most common benign pathology found in the remaining patients. Discrete mass was the most frequently encountered lesion detected on mammography and US, followed by mass containing calcifications. Patients with advanced age, having a clinically palpable breast mass, with mammographic and US evidence of mass containing calcifications showed significant statistical association with breast cancer.

PPV of BI-RADS category 5 lesions in the present study was comparable to other published studies. Although the probability of malignancy was very high, a small number of patients had benign pathologies. Preoperative histopathologic diagnosis is necessary before definitive treatment.