Objective: To assess the efficiency of transvaginal ultrasonography in the screening of endometriomas and in differentiating endometriomas from other ovarian masses.
Design: Prospective study with surgical and pathological confirmation of the sonographic diagnosis.
Setting: Department of Obstetrics and Gynecology at the University of Cagliari, Cagliari, Italy.
Patients: All premenopausal nonpregnant women (n = 236) submitted to laparotomy or laparoscopy from May 1991 to December 1992.
Interventions: Transvaginal ultrasonographic examinations were done within 1 week before surgery. Ultrasonographic diagnosis was compared with surgical and histopathological findings.
Main outcome measure: The visualization of round-shaped homogeneous hypoechoic "tissue" of low-level echoes within the ovary was chosen as characteristic ultrasonographic finding of endometrioma. Sensitivity, specificity, and predicted values were calculated for each visualized ovary (group A) to assess the efficiency in the screening, and for each visualized cyst (group B) to assess the efficiency in differentiating endometriomas from other ovarian masses.
Results: Four hundred twenty-three of 466 ovaries were visualized. Of the 82 visualized cysts, 27 were suspected to be endometriomas, and the diagnosis was confirmed by pathology in 21. The sensitivity and the specificity were 75% and 99%, respectively, in group A, and 84% and 90%, respectively, in group B.
Conclusion: The study demonstrates that transvaginal ultrasonography has an efficiency of 88% in differentiating endometriomas from other ovarian masses with a specificity of 90%.