Transient erythroblastopenia of childhood with CD10, TdT, and cytoplasmic mu lymphocyte positivity in bone marrow.

Over three years, three children presented with anaemia, reticulocytopenia, and marrow erythroblastopenia. A pronounced lymphocytosis was also evident in two of the marrow aspirates, with increased numbers of cells bearing the immunophenotype TdT+, CD10+ HLA DR+, and cytoplasmic mu +, and reported to be compatible with acute lymphoblastic leukaemia (ALL). The clinical course of the illness was fully compatible with transient erythroblastopenia of childhood (TEC), and all three children remained well one to four years after initial presentation. It is concluded that increased numbers of lymphoid cells with a common or pre-B ALL phenotype may be found in bone marrow aspirates of children with TEC, and should not be misdiagnosed as acute leukaemia.