Hematolymphoid lesions of the breast.

Hematolymphoid malignancies of the breast are most commonly neoplasms of mature B-lymphocytes, and may arise as a primary disease or by secondary involvement of a systemic disease. Primary breast lymphomas (PBL) account for 0.04-0.5% of breast malignancies, less than 1% of all non-Hodgkin's lymphomas (NHL), and less than 5% of extranodal lymphomas (Lakhani et al., 2012; Swerdlow et al., 2008; Joks et al., 2011; Barişta et al., 2000; Giardini et al., 1992; Brogi and Harris, 1999; Topalovski et al., 1999). Secondary breast lymphomas (SBL) are also rare, with an estimated annual incidence of 0.07% (Domchek et al., 2002; Talwalkar et al., 2008). Recognition of breast lesions as hematolymphoid is critical to distinguish them from other entities that can occur in the breast.