Anaplastic large cell lymphoma,lymphohistiocytic variant:report of 2 ALK~+ children and review of literatures / 第三军医大学学报

ABSTRACT

Objective To study the clinicopathological characteristics,diagnosis and prognosis of anaplastic large cell lymphoma,lymphohistiocytic variant(ALCL-LH).Methods Two cases of ALCL-LH were diagnosed according to the WHO standard of lymphoma classification.Their clinical manifestations were analyzed.Lymphoma sample sections were prepared for pathological features and immunohistochemical assays,and examined by in situ hybridization for Epstein-Barr virus(EBV)DNA.Concerning literatures were reviewed.Results Both 2 cases occurred in children.The clinical manifestations presented with fever and enlarged lymph nodes as well as hepatomegaly and splenomegaly.Microscopically,the neoplastic cells,with irregular nuclei,were more often medium to large in size but smaller than those in the common type,and sparsely intermixed with a large number of histiocytes and lymphocytes that exceeded and masked the tumor cell population.The tumor cells clustered around blood vessels.Case 1 showed evidence of erythrophagocytosis.Immunohistochemical stainings showed that tumor cells of 2 cases were positive to CD30,anaplastic lymphoma kinase(ALK),EMA,and Granzyme B,as well as case 1 to CD43,and case 2 to CD7.But both cases were negative to CD45,CD2,CD3,CD4,CD5,CD8,CD45RO,CD56,CD20,CD79a,CD15,MPO,CK,TdT,and LMP1.In addition,the EBV DNA was not detected in the lymphoma.Case 1 and case 2 died 10 d and 3 months after pathological diagnosis respectively.Conclusion ALCL-LH variant is rare subtype,and often occurs in pediatric patients.Morphologically,ALCL-LH is characterized by a few medium to large size cells admixed with a large number of histiocytes and lymphocytes that exceed and mask the tumor cell population.The expressions of CD30,ALK,EMA and cytotoxic granule associated proteins contribute to diagnosis and differential diagnosis.