Diagnosis and treatment of pediatric anaplastic lymphoma kinasepositive large B-cell lymphoma: A case report

BACKGROUND Anaplastic lymphoma kinase-positive(ALK+) large B-cell lymphoma(LBCL) is a rare type of lymphoma with high invasiveness and rapid progression. It occurs in all age groups, but is extremely rare in children. The lesions mainly involve the lymph nodes and may present with extra-nodal involvement. Response to conventional chemotherapies and local radiotherapy is poor, with a 5-year overall survival of less than 40%. Recently, the use of ALK inhibitors for the treatment of this disease has been reported.CASE SUMMARY We present a case of a 12-year-old boy diagnosed with ALK+LBCL. The patient had a 2-mo medical history of a calvarial mass, extensive systemic involvement, and positive bone marrow clathrin heavy chain(CLTC)-ALK fusion gene. Complete remission 1(CR1) was achieved using the modified LMB89 Group C regimen followed by autologous stem cell transplantation. The patient relapsed 3 mo later.He then achieved CR2 with three short courses of chemotherapy(COP, reduceddose ICE, low-dose Ara-c+VP16) and continuous alectinib targeted therapy. Afterward, allogeneic hematopoietic stem cell transplantation(allo-HSCT) was performed. At 16 mo after the allo-HSCT, the patient was still in CR2.CONCLUSION The modified LMB89 Group C regimen and ALK inhibitors are effective. AlloHSCT should be performed after remission.