Ultrasonographic versus clinical evaluation of a pelvic mass.

Ultrasonography has become an essential tool in the practice of modern obstetrics. Its usefulness in the evaluation of a pelvic mass in gynecologic practice remains unclear. The present investigation is a comparison of pelvic examination findings and preoperative ultrasound findings in 72 patients who underwent exploratory laparotomy for a pelvic mass at the Nation Naval Medical Center. Of the 72 patients, 65 (90%) were correctly diagnosed as having a pelvic mass by both pelvic examination and ultrasonography. The ultrasound study had a 5.6% false-negative rate (4 patients), and 4.4% (3 patients) had false-positive pelvic examinations. There was no significant difference by chi 2 analysis in accuracy between ultrasonography and pelvic examination in detection, estimation of size, or determining the unilateral or bilateral position of the mass (P less than .05). Ultrasonography was significantly more accurate in determining the cystic or solid nature of the mass (P greater than .05). In no patient was the decision to perform exploratory laparotomy altered by the preoperative ultrasound study. It is concluded from this investigation that routine ultrasonography is not necessary in the preoperative evaluation of a pelvic mass unless the cystic or solid nature of the mass will modify the patient's treatment.