Breast cysts: pitfalls in sonographic diagnosis.

Ultrasound examination of the breast is extensively carried out to differentiate cystic from solid masses. Ten atypical cysts are presented that do not fulfil all the criteria for the ultrasonic diagnosis of breast cysts. These had internal echoes and some showed irregular contours or diminished through transmission. Diagnostic aspiration confirmed the cystic nature of these lesions. None showed cytologic evidence of malignancy or haemorrhage. The purpose of this paper is to bring this entity to the attention of radiologists so that echogenic cysts are considered in the differential diagnosis of well defined, solid appearing breast masses seen on ultrasound.