Case 46 Answer 3
BI-RADS 4, Suspicious. This is a complex mass with cystic and colid components, and is suspicious for malignancy. This had been deemed a "cyst" and called benign for several years as it grew before a mammographer appropriately recognized the multiple solid portions as a real and concerning finding. The biopsy revealed infiltrating ductal carcinoma.
A trap lies for anyone who grows complacent about ignoring artifactual internal echoes on ultrasound. Legally, one is taking a risk if one accepts images with internal echoes and assumes a mass is a cyst. If a cancer develops anywhere near this location in the breast, even if it does not stem from the initial lesion imaged, one has now documented in the medical record a "possible" solid mass. The mammographer should repeat the ultrasound with the appropriate settings and prove one way or the other that the mass is a simple cyst. If this cannot be shown with ultrasound, it must be assumed to be a cyst vs. solid mass, and aspiration should be performed.
See related cases below.