ALK and neoplasm: According to the WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues, there are four subtypes of anaplastic large cell lymphoma: ALK-positive ALCL (ALK+ALCL), ALK-negative ALCL (ALK−ALCL), primary cutaneous ALCL (pcALCL), and breast-implant-associated ALCL (BIA-ALCL) [11].