ACOUSTIC SHADOWING FROM UTERINE LEIOMYOMAS - SONOGRAPHIC-PATHOLOGICALCORRELATION

PURPOSE: To investigate the origin of discrete shadowing from uterine leiomyomas at ultrasound (US) that does not progress from an echogenic origin. MATERIALS AND METHODS: Seven hysterectomy specimens with leio myomas were scanned in a water bath, With US guidance, 13 self-retaini ng needles were placed at the origin of shadows that did not (12 cases ) or did (one case) arise from an echogenic focus. The localized tissu es were inspected for gross pathologic features and microanatomic deta il. RESULTS: In the 12 cases, the shadow originated from transitional zones: the margins of the fibroid with adjacent myometrium (three need les), the edges of nodular whorls of smooth muscle (four needles), and the margin between smooth muscle bundles and hyalinized connective ti ssue (five needles). There was no evidence of calcification, hemorrhag e, or necrosis. In the other case, microcalcifications were found. CON CLUSION: Discrete shadowing not arising from echogenic foci resulted f rom the structural features of the leiomyomas and occurred at transiti onal boundaries between juxtaposed tissue types or at the curved margi ns of organized anatomic structures.