Diagnosis of non-palpable breast lesions: an ultrasound and cytology-based approach: the experience of the Institut Curie in a series of 3865 ultrasound-guided fine needle aspirations ; Diagnostic des lésions mammaires non-palpables : l’approche écho-cytologique : l’expérience de l’Institut Curie sur une série de 3865 lésions ponctionnées sous guidage échographique

Our study assessed the diagnostic performance of ultrasound (US)-guided fine needle aspiration (USFNA) in non- palpable breast lesions (NPBLs) and correlations between ultrasound, cytological and histological presentations of underscored (i.e malignant BI-RADS 3) and overscored (i.e benign BIRADS 4C and 5) NPBLs. Between 2003 and 2007, 3865 consecutive USFNA of NPBLs were performed and recorded at the Institut Curie. Clinical data, breast-ultrasound, cytology and pathology records for each NPBL were retrieved and analyzed. USFNA's sensitivity, specificity were respectively 0.93 (95% CI =[0.91,0.94) and 0.97 (95% CI = [0.96,0.98]). The best diagnostic performance was found in under50-year old patients and low BI-RADS categories.High-grade invasive carcinomas and specific types of carcinomas, represented most underscored NPBLs and were easily diagnosed at USFNA: in these cases USFNA alone can suffice to establish a diagnosis. Performance was lowest in cancers with very low mitotic counts, and among over-scored NPBLs, in epithelial and fibrous proliferations, intraepithelial proliferations, papillomas and benign tumors. These categories represented most over-scored NPBLs.These presented specific US features of shape, ultrasound pattern and posterior US-beam transmission to identify them. We therefore suggest using USFNA and core-needle biopsy in conjunction in higher BI-RADS categories, especially when such specific findings are found before biopsy. ; Notre étude évaluait la performance diagnostique de la cytoponction mammaire échoguidée (CME) dans les lésions mammaires non-palpables (LMNP) et les corrélations échographiques, cytologiques et histologiques des LMNP sous-estimées(BI-RADS 3 malignes) et sur-estimées (BI-RADS 4C et 5 bénignes). Entre 2003 et 2007, 3865 CME consécutives étaient réalisées sur des LMNP à l’Institut Curie. Les données cliniques, d’imagerie, de cytologie et d’histologie ont été revues et analysées. La sensibilité et la spécificité de la CME étaient de 0.93 (IC95%=[0.91,0.94) et 0.97 ...