T-cell/Histiocyte-rich Large B-cell Lymphoma : Spleen

Comments:
Splenic involvement in T-cell/histiocyte-rich large B-cell lymphoma (THRLBCL): THRLBCL is primarily a nodal disease, although extranodal sites are frequently involved, including bone marrow (60% of cases) and spleen (25% of cases; shown here).

Splenic involvement is characterized by a micronodular pattern in the white pulp. Individual micronodules have similar composition to the nodal lesions - they are composed of scant numbers of large atypical B-cells in a background of abundant reactive T-cells.

This image taken from white pulp areas shows a polymorphous cell population consisting predominantly of small lymphocytes that were positive for T-cell markers, and scattered large atypical cells. that expressed B-cell markers and were negative for CD15 and CD30 (associated with Hodgkin lymphoma).