ALK and primary effusion lymphoma: However, PBL needs to be distinguished from other large B-cell lymphomas in morphology, Such as plasmablastic plasma cell lymphoma, Burkitt lymphoma, anaplastic lymphoma kinase (ALK) positive anaplastic DLBCL, primary exudative lymphoma (PEL), multicentric Castleman large B-cell lymphoma and HHV-8 positive DLBCL (1).