Extravisceral masses in the peritoneal cavity: Sonographically guided biopsies in 52 patients

OBJECTIVE, Our objective was to determine the effectiveness of sonographically guided biopsies of extravisceral masses (masses outside the solid organs) in the peritoneal cavity, MATERIALS AND METHODS. We retrospectively reviewed the results of sonographically guided biopsies of extravisceral masses found in the peritoneal cavity of 52 patients (age range, 25-90 years old; mean age, 52 years) from June 1990 to December 1996. Fifty-one patients underwent biopsy through the abdominal wall, and one patient underwent transvaginal biopsy. Sonographic guidance was obtained using 3.5- to 7.0-MHz vector probes, The size, depth, and sonographic characteristics of the mass and the type of biopsy (aspirate versus core) were determined for all lesions. Pathology reports and clinical courses were reviewed. RESULTS. Placement of the biopsy needle within the lesion was successful in all patients. The mean depth from skin surface to lesion was significantly less (p <.0001) when shown by sonography (2.4 cm) than when shown by CT (3.8 cm). Biopsy results were true-positive for malignancy in 37 patients (no false-positives), true-negative for benign masses in 10 patients, and false-negative for malignancy in three patients (sensitivity, 93%; specificity, 100%; accuracy, 94%). Nondiagnostic samples were obtained in two patients (4%). Treatment was based on diagnostic biopsy results in 43 patients (86%). CONCLUSION. Sonography is an effective alternative to CT in guiding biopsy of extravisceral masses in the peritoneal cavity.