Extramedullary recurrence of acute lymphoblastic leukemia 15 years after initial diagnosis

We describe a 19-year-old man with recurrence of a lymphoid malignancy involving the ethmoid sinus 15 years following diagnosis and 10 years after discontinuation of therapy for childhood acute lymphoblastic leukemia (ALL). The cytologic appearance and immunologic phenotype of the tumor cells suggest that this malignancy represents a recurrence of his original tumor. Initial relapse of ALL is unusual after 4 years of continuous remission off therapy. This case illustrates that late relapse can occur and may present with unusual sites of involvement.