BI-RADS 4 and 5 breast lesions: correlation between sonographic findings and histopathological results following ultrasound-guided FNAC

Abstract

Background: clinical application of breast imaging reporting and data system (BI-RADS) lexicon for breastultrasound useful to characterization of breast lesion and to inform the level of likelihood of malignancy. Objectives: to correlate between the ultrasound findings and pathological results of BIRADS 4 and 5 lesions on thebasis of the imaging-pathologic concordance or discordance. Methodology: This prospective study enrolled 185 patients classified as BI-RADS-4 and BI-RADS-5, who were referred for breast ultrasound examination at breast clinic in oncology hospital-medical city complex-Baghdad that obtained between January 2013-August 2013 who had palpable breast lump on clinical examination or mass detected by mammography. Ultrasound findings were reviewed by board-certified radiologist and description of ultrasound finding bases on fourth edition BI-RADS lexicon; BI-RADS 4 and 5 was selected for breast lesions that were features suggesting malignancy, category 5 having more likelihood of malignancy than category 4. In both cases, ultrasound guided fine needle aspiration cytology (FNAC) were performed then pathological diagnoses were obtained. Finally, five possible results illustrated for ultrasound-pathology correlation according the concordance and discordance between ultrasound findings and pathological results and malignancy rates were estimated. Results: Over a period of 8 months, 185 patients with BI-RADS 4 and 5 breast lesions were included in this study; the age at presentation ranged between 20 to 73 years. The mean age was 39 years. High resolution ultrasound with Doppler facility applied on all patient and results are categorized according breast imaging and reporting data system and category 4 and 5 were ended by fine needle aspiration cytology with ultrasound guidance and subsequently the histopathology was done. FNAC results revealed 68.35% (n=108) of BI-RADS 4 patients had benign pathologies, 18.99% (n=30) had malignancy and just 12.66% (n=20) showing borderline or high risk lesions. The majority (85.18%) of women with BI-RADS 5 displayed malignant lesion and benign lesions were 2% and rest were borderline. following imaging-pathology correlation, the concordant malignancy in BI-RADS 4 was 18.9% versus 85.18% in BI-RADS 5 and discordant benign in BI-RADS 4 noted in 68.3% of patients while only in 7.4% in BI-RADS 5 and borderline high-risk lesion identified in 12.6% in BI-RADS 4 and 7.4% in BI-RADS 5. Conclusion: the current study shows high agreement with the likelihood of malignancy after application of BI- RADS terminology in category 4 and 5. Careful imaging-pathologic correlation is integral part of multidisciplinary team and very important in establishing the concordance. Recommendation: the previous knowledge about fourth edition of ACR BI-RADS lexicon and practicing it in daily work recommended for radiologist who working in dedicated breast care centers to avoid delays in diagnosis of breast malignancy