Two Relapsed Stage III Childhood Anaplastic Large Cell Lymphoma Patients with NPM-ALK Fusion in Bone Marrow from Initial Diagnosis

Childhood anaplastic large cell lymphoma (ALCL) accounts for approx. 10-30% of cases of non-Hodgkin lymphoma, and the ALCL99 study reported 60-75 disease-free survival; however, a relatively high relapse rate was observed (25-30% ). We report 2 patients with Stage III ALCL who relapsed 6-18 months after the end of ALCL99 chemotherapy. A retrospective molecular analysis identified the nucleophosmin (NPM)-anaplastic lymphoma kinase (ALK) fusion gene in the first diagnostic bone marrow samples taken from both patients. However, antibodies against the ALK protein appeared to be relatively low in the serum of both patients (×100 and ×750). An increase in chemotherapy intensity may be beneficial if Stage III ALCL patients are shown to be NPM-ALK chimera-positive in the first diagnostic bone marrow sample.