ALK and mediastinal malignant lymphoma: On the other hand, the most common subtypes of aggressive B-NHL are large B-cell lymphomas, which is composed of DLBCL, not otherwise specified (NOS, 80%) and additional 13 specific variants of DLBCL (20%) including anaplastic (ALK + LBCL) and primary mediastinal lymphoma (PMLBCL), and other various kinds of DLBCL [303–306].