Aggressive angiomyxoma: findings on CT and MR imaging.

OBJECTIVE: Aggressive angiomyxoma is a benign tumor affecting the pelvis and perineum, predominantly in women. Because of its variable presentation as a soft mass in the vulva, perianal region, buttock, or pelvis, the tumor is often clinically misdiagnosed and initial surgery is usually unsuccessful in extirpating it. This study describes the imaging features of these tumors. CONCLUSION: Aggressive angiomyxomas display unusual growth patterns of translevator extension with growth around perineal structures. Both CT and MR imaging show the transdiaphragmatic extent of these tumors. High signal intensity on T2-weighted MR images may reflect the myxomatous stroma of these tumors.

Transvenous renal biopsy in an ex vivo swine kidney model: a comparison of five devices.

PURPOSE: To compare the efficacy of end-cut and side-cut devices in transvenous renal biopsies of ex vivo swine kidneys and to examine the use of the swine kidney as an animal model in this setting. MATERIALS AND METHODS: Biopsy specimens of ex vivo swine kidneys were obtained after selective renal vein cannulation with use of five separate biopsy devices (Quick-Core 16 gauge and 18 gauge, Colapinto 16 gauge, Mansfield biopsy forceps, Flexi-Temno 16 gauge). Biopsy specimens were defined as the material obtained from three separate passes at a given site, with 30 biopsy specimens obtained per device. Capsular perforation was examined for each pass. A blinded pathologist recorded the presence of tissue and the number of glomeruli present for each pass. A diagnostic biopsy was defined as six or more glomeruli obtained. RESULTS: The median number of glomeruli obtained for each device per biopsy was Colapinto 0.0 (range, 0-13), Mansfield 0.0 (range, 0-19), Flexi-Temno 2.0 (range, 0-13), 18-gauge Quick-Core 8.5 (range, 0-30), and 16-gauge Quick-Core 16.0 (range, 0-52). The Quick-Core 16-gauge and 18-gauge devices obtained diagnostically adequate biopsy specimens 83% and 77% of the time, respectively, compared to 20% or less for the other devices. CONCLUSION: The Quick-Core 16-gauge and 18-gauge side-cut biopsy devices are the most efficacious for obtaining diagnostic quality biopsy specimens in the ex vivo swine kidney model.