MR imaging of müllerian mucinous borderline tumors arising from endometriotic cysts.

This report describes MR findings of müllerian mucinous borderline tumors, pathologically proven to have arisen from endometriotic cysts, in three patients. They were unilocular or paucilocular masses with mural nodules. Cystic components showed hyperintensity on both T1- and T2-weighted images, simulating clear cell or endometrioid carcinomas arising from endometriotic cysts. Mural nodules showed prominent high signal intensity on T2-weighted images. Correlation with pathologic findings suggests that this hyperintensity reflects intraluminal mucinous material and stromal edema.