IRF4 locus gene rearrangement is seen in 20% to 75% of cases [34,35], while ALK rearrangement has traditionally been equated with systemic ALK-positive ALCL however, a small number ofcases of ALK-positive ALCL confined to the skin have been reported, predominantly in pediatric patients [36,37]. Here, ALK is linked to anaplastic large cell lymphoma.