CD56‐expression in bone marrow or other relevant tissue samples related to histopathological diagnosis and clinical outcome in children

Abstract

In normal bone marrow CD56-expression is low, but in acute leukemia or lymphoma in adults a marked increase in CD56-expression is associated with a worse clinical outcome. In children, however, it is unclear whether a high CD56-expression relates to the histopathological diagnosis and prognosis. In a five-year period (2000-05) we retrospectively assessed medical files of children below 15 years of age. As established by flowcytometry, bone marrow or other relevant tissue samples with a percentage of CD56+ cells higher than 10% were selected. Ten patients (age 5.1 ± 1.2 yr; mean ± SEM) were included and in most patients CD56+ analysis was performed at the time of diagnosis. Six patients had acute myeloid leukemia (AML) (66 ± 11% cells expressing CD56) and the remaining four patients were with cutaneous lymphoma (20%), myeloid sarcoma in pleura (40%), juvenile myelomonocytoid leukemia (27%) or large cell anaplastic T-cell lymphoma (13%), respectively. Two patients with AML and the patient with myeloid sarcoma in pleura died 11 ± 3 months after the diagnosis was established and the %CD56+ cells was 66 ± 13 as compared to 43 ± 12 in the remaining seven children who are still alive (follow-up time 28 ± 11 months). In this group one patient relapsed during treatment. Our cases with a high expression of CD56+ cells relates to a wide range of diagnosis. As in adults the data suggests that in children the expression of CD56 in acute leukemia is associated with a bad outcome.