ALK and anaplastic large cell lymphoma: The predominantly nodal PTCL represents 60% to 70% of all PTCL, and includes peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS), angioimmunoblastic T-cell lymphoma (AITL), and anaplastic large cell lymphoma (ALCL), which is further subdivided intoanaplasticlymphoma kinase (ALK) positive and negative variants [4].