Malai MuttarakKanchana SrivichaiBenjaporn ChaiwunNeelaya Sukhamwang2011-02-162011-02-162010-10-152010-10-15Chiang Mai Medical Journal; Vol.49 No.3 September 2010 (pages 81 - 121); 111 - 116http://imsear.searo.who.int/handle/123456789/130638Objective Materials and methods fi ndings, and pathological results were recorded. The positive predictive value (PPV) ofBI-RADS categories 4 and 5 were analyzed.Results fi cations, was the most common imaging abnormality. Fibroadenoma and fi brocysticchange were the most common benign lesions leading to biopsy. The most common histologicdiagnosis of malignancy was invasive carcinoma. The most common biopsy method wasfi ne-needleaspiration.Conclusion fi cations, had a high chance of malignancy. Preoperative biopsy shouldbe performed before defi nite treatment in all suspicious mammographic fi ndings because ofthe overlap in mammographic appearances of benign and malignant breast lesions. Fine needleaspiration biopsy (FNAB) was the most common method used in this study.Chiang Mai MedicalJournal 2010;49(3):111-116.The BI-RADS categorization is useful in predicting the chance of malignancy. Breastmass, with or without calciThe PPV for BI-RADS 4 was 26.6% and BI-RADS 5 89.5%. Mass, with or withoutmicrocalciInstitutional Reviewed Board approval was obtained. From 12,284 women,who underwent screening and diagnostic mammography at our institution, 236 were categorized asBI-RADS 4 and 144 as BI-RADS 5 between January 2006 and December 2008. Biopsy methods,imagingTo determine the positive predictive value of BI-RADS categories 4 and 5.en-USChiang Mai Medical JournalOriginal Articles