Large cell lymphoma of bone. A report of three cases of B-cell origin.

Clinicopathological and immunohistological features of three cases of large cell lymphoma of bone are reported. On histological grounds, all the cases were diagnosed as histiocytic lymphomas (Rappaport) or primary centroblastic lymphomas, polymorphic subtype (Kiel). On immunophenotyping, malignant cells strongly reacted with the anti-leucocyte antibodies PD7/26 and ROS-220C, thereby indicating their lymphomatous nature, and expressed the B-cell antigens CD19 and CD22. Further studies are warranted to determine whether the B-cell phenotype observed in our cases is typical of the majority of primary large cell lymphomas of bone. Immunohistological analysis with monoclonal antibodies is expected to be of great value not only in defining the immunological phenotype of this rare pathological entity, but also in differentiating it from other neoplasms that involve the skeleton, either primarily or secondarily.