Chronic lymphocytic leukemia involving the breast parenchyma, mimicker of invasive breast cancer: differentiation on breast MRI.

Leukemic involvement of the breast is rare, particularly involvement by chronic lymphocytic leukemia (CLL). While concurrent invasive ductal carcinoma and CLL manifesting as a collision tumor in the breast is extremely rare, this association (CLL and carcinoma) has been described in other organs. We report here a case of a 58-year-old woman with concurrent invasive ductal carcinoma and CLL and describe the imaging features of CLL, particularly the differentiation on MRI.