Chronic lymphocytic leukemia mimicking recurrent carcinoma of the breast: Case report and review of the literature

Secondary localization of chronic lymphocytic leukemia (CLL) in breast is rare, while concurrent invasive ductal carcinoma and CLL manifesting as a collision tumor in breast is extremely rare.The observation of a CLL infiltration closely associated with a distinct breast neoplasm with the absence of any other localization for the leukemia is an indisputable argument for a relationship between the two diseases. The presence of both tumors is not simply due to chance. This association (CLL and carcinoma) has also been described in other organs.Hereafter, we report a second case of an 80 year-old woman in whom a leukemic infiltrate was confined to the region immediately surrounding poorly differentiated primary breast carcinoma, and we will discuss the association between CLL and carcinoma.