We report four cases of a finding of communication between the endometrial cavity and adenomyotic lesions observed during saline contrast sonohysterography. In each case there was a saline-filled defect extending from the endometrial cavity into the myometrium in the region of previously suspected adenomyosis. We believe this finding represents the sonohysterographic correlate of endometrium invading the myometrium, as has been described histologically. Copyright © 2010 ISUOG. Published by John Wiley & Sons, Ltd.