Diagnostic Accuracy of Sonography and Combined Sonographic Assessment and Sonographically Guided Cytology in Nonpalpable Solid Breast Lesions Fabienne Thibault, MD, 1 Martine Meunier, MD, 1 Jerzy Klijanienko, MD, 2 Carl El Khoury, MD, 3 Claude Nos, MD, 4 Anne Vincent-Salomon, MD, 2 Bernard Asselain, MD, 5 Sylvia Neuenschwander, MD 1 1 Department of Radiology, Institut Curie, 26 Rue d’Ulm, 75231 Paris Cedex 05, France 2 Department of Pathology, Institut Curie, 26 Rue d’Ulm, 75231 Paris Cedex 05, France 3 Department of Radiology I, Ho ˆpital Henri Mondor, 51 Avenue du Mal De Lattre De Tassigny, 94010 Cre ´teil, France 4 Department of Surgery, Institut Curie, 26 Rue d’Ulm, 75231 Paris Cedex 05, France 5 Department of Biostatistics, Institut Curie, 26 Rue d’Ulm, 75231 Paris Cedex 05, France Received 2 June 1999; accepted 9 June 2000 ABSTRACT: Purpose. The aim of this study was to assess the diagnostic accuracy of sonography alone and combined sonographic assessment and sono- graphically guided fine-needle aspiration cytology in solid, nonpalpable lesions of the breast. Methods. We retrospectively evaluated the sono- grams from a series of 174 consecutive nonpalpable masses that were cytologically diagnosed using fine- needle aspiration under sonographic guidance and then histologically verified through surgical excision. We examined the relationships between the findings from sonography, combined sonographic assessment and cytopathology, and histology. Results. Histologically, 95 lesions (55%) were ma- lignant and 79 (45%) were benign. The overall sensi- tivity of sonography alone for diagnosing cancer was 98.9% (94 of 95 lesions), and the specificity was 45.6% (36 of 79 lesions). One (3%) of 37 masses considered at sonography to be benign was correctly diagnosed on cytologic examination to be cancer. By establish- ing the benign status of 11 of 13 masses that were indeterminate at sonography, cytology increased the specificity of the combined method (to 56.3%). Cytol- ogy appropriately suspected or confirmed malignancy in 79 (84%) of 94 carcinomas considered at sonogra- phy to be suspicious or malignant. Conclusions. In this study, sonography alone dem- onstrated a high sensitivity but limited specificity in evaluating nonpalpable breast masses. The addition of sonographically guided cytology substantially in- creased the specificity of the combined method with- out compromising sensitivity. © 2000 John Wiley & Sons, Inc. J Clin Ultrasound 28:387–398, 2000. Keywords: breast, carcinoma; ultrasonography; fine- needle aspiration; breast, nonpalpable lesions S creening mammography often detects sub- clinical abnormalities that require a definite diagnosis. Sonography employing high-frequency (7.5–10-MHz) transducers is a sensitive tech- nique for demonstrating nonpalpable lesions de- tected on mammography. The most widely ac- cepted use of breast sonography has been in distinguishing cysts from solid lesions. Investiga- tors using high-resolution breast sonography with strict imaging criteria have shown that this technique may also help classify some solid nod- ules as benign. 1,2 However, in cases in which le- sions lack suspicious sonographic findings but do not meet all the criteria for benign lesions, a tis- Correspondence to: F. Thibault © 2000 John Wiley & Sons, Inc. VOL. 28, NO. 8, OCTOBER 2000 387