Case showing two images with clusters of crystal storing histiocytes in the spleen amidst a case of follicular lymphoma transformed to a diffuse large B-cell lymphoma.

These CSH are typically replete with immunoglobulin crystals  and have been described mostly in the context of low-grade lymphomas including marginal zone lymphomas, lymphoplasmacytic lymphoma or plasma cell neoplasms. It is thought that these peculiar histiocytes are a result of immunoglobulin alterations and/ or possibly defects in the ability of histiocytes to process the immunoglobulin.