Are there site-specific differences among extranodal aggressive B-cell neoplasms?

Aggressive B-cell lymphomas, including diffuse large cell, Burkitt, and lymphoblastic types, may affect a wide variety of extranodal sites. Up to 40% of these tumors are initially diagnosed in extranodal locations. Regardless of site, these tumors have many histologic similarities; however, some clinical, cytologic, immunologic, and etiologic features of these tumors seem to be distinctive for particular sites of extranodal presentation. In accordance primarily with the extranodal locations presented at the Society for Hematopathology Fourth Slide Workshop on Extranodal Hematopoietic/Lymphoid Disorders (Excluding Bone Marrow and Spleen), the distinctive features of the aggressive B-cell lymphomas of the mediastinum, breast, bone, skin, and body cavities as well as the rare, but primarily extranodal intravascular lymphomatosis, will be discussed.