FINE-NEEDLE BIOPSY SPECIMENS OF BENIGN BREAST-LESIONS DISTINGUISHED FROM INVASIVE CANCER EX-VIVO WITH PROTON MR SPECTROSCOPY

PURPOSE: To determine whether invasive breast cancer can be distinguis hed from benign lesions with proton magnetic resonance (MR) spectrosco py ex vivo on the basis of altered cellular chemistry. MATERIALS AND M ETHODS: Two hundred eighteen fine-needle biopsy specimens were obtaine d in 191 patients undergoing surgery and were analyzed with proton MR spectroscopy. MR spectroscopic and histopathologic findings were compa red. RESULTS: Invasive carcinoma produced increased signal at 3.25 ppm , attributable to choline-containing metabolites. Discrimination betwe en invasive carcinoma (n = 82), benign lesions (n = 106), or carcinoma in situ (n = 17) was based on the resonance intensity at 3.25 ppm sta ndardized to the resonance at 3.05 ppm (P < .001). The ratio of peak h eight intensities of resonances at 3.25 to those at 3.05 ppm was less than 1.7 in 102 of the 106 normal or benign lesions. All carcinoma in situ specimens with comedonecrosis or a microinvasive component (n = 6 ) were categorized at MR spectroscopy with invasive carcinoma, while o thers with in situ disease alone were categorized with benign lesions (n = 11). The sensitivity and specificity of MR spectroscopy in fine-n eedle biopsy specimens in distinguishing benign lesions from invasive cancer were 95% and 96%, respectively. CONCLUSION: Proton MR spectrosc opy of fine-needle biopsy specimens provides objective diagnostic info rmation that complements findings of conventional preoperative investi gations of breast lesions.