Michiya NATORI¹, Miwa SAITOH², Yasuhiro UDAGAWA², Toyohiko MIYAZAKl², Danilo T GABIONZA³, Shiro NOZAWA²

¹Department of Clinical Research National Ohkura Hospital, ²Department of Obstetrics and Gynecology Keio School of Medicine, ³Department of Anatomy Keio School of Medicine

キーワード : Echo pattern , Malignancy, Ovarian tumor , Sonography

The Japan Society of Ultrasonics in Medicine proposed the echo-pattern classification of ovarian tumors in 1994. The present study was designed to evaluate the usefulness and reliability of this standard in predicting malignancy or benignity prospectively. The 94 participating patients all underwent surgery in our institutions after being diagnosed as having ovarian tumor. Type-IV tumor had the highest incidence (32%), and type-II had the second highest (26%).　Probability of benignity decreased going up the scale from type-I to type VI while the probability of malignancy increased. None of the type-I and II tumors were malignant. Endometriomas comprised 79% of type-II tumors. Seventy-two percent of tumors classified as type-III were mature cystic teratomas; three type-III tumors were malignant. Forty-three percent of type-IV tumors were malignant, or having borderline malignancy. Type-IV included mature cystic teratomas (23%) and endometriomas (17%). Seven of the eight cases classified as type-V or type-VI were malignant. We reclassified all of the tumors as benign or malignant: types-I, II and III were regarded as benign; types-IV, V, and VI were regarded as malignant. Seventeen of the 30 type-IV tumors were false-positive, and 3 (13%) of the type-III tumors were false-negative. Sensitivity and specificity of this method were 87% and 75%, respectively. This echo-pattern classification may facilitate and improve the diagnostic acumen of examiners who lack extensive experience.