Diagnosis of acquired bone marrow failure syndrome during childhood using the 2008 World Health Organization classification system

Abstract

Distinguishing hypoplastic myelodysplastic syndrome from aplastic anemia (AA) is challenging. In the present study, Japanese and Chinese pediatric hematologists and pathologists conducted a joint review of bone marrow (BM) smears and trephine biopsies in 100 children with acquired BM failure syndrome, using the criteria proposed in the 2008 edition of the World Health Organization classification of hematopoietic and lymphoid tissues. The final consensus for the diagnoses of 100 children was AA in 29 patients, refractory cytopenia of childhood (RCC) in 58 patients, and refractory cytopenia with multilineage dysplasia (RCMD) in 13 patients. No significant differences between Japanese and Chinese children were found with regards to clinical and laboratory findings, or the distribution of diagnoses. Patients with RCC/RCMD showed milder disease severity and BM hypocellularity than those with AA. To establish the provisional entities for RCC, it is essential to prospectively compare the clinical outcomes between AA and RCC groups in a large number of patients.

Pediatric aplastic anemia and refractory cytopenia: A retrospective analysis assessing outcomes and histomorphologic predictors

“…The clinical relevance of the diagnosis of RCC remains controversial. Our data, and that of Yang et al , showed an association between conventionally diagnosed MAA and RCC (Table ). Because RCC is a subcategory of MDS, it has traditionally been treated with up front HSCT in an attempt to provide curative therapy prior to progression to clonal hematopoiesis or leukemia.…”

“…RCC remains a controversial classification that has not been widely adopted, largely due to limited data on the clinical implications of this diagnosis . The European Working Group of Childhood MDS (EWOG‐MDS) developed histomorphologic criteria to differentiate SAA from hypocellular RCC and demonstrated reproducibility of these criteria .…”

“…The majority of RCC patients present with a hypocellular bone marrow ; therefore, the histologic distinction between AA and RCC is challenging and requires the collaboration of experienced hematologists and hematopathologists, as well as cytogenetic and molecular analyses. RCC has been a controversial entity and has not been universally accepted, especially because the therapeutic and prognostic implications of the diagnosis have only been validated in a limited number of studies . The distinction between AA and RCC can be somewhat confusing especially given the controversy around different taxonomies used to describe the BMF disorders.…”

Comparison of long-term outcomes between children with aplastic anemia and refractory cytopenia of childhood who received immunosuppressive therapy with antithymocyte globulin and cyclosporine

“…None of the RCMD patients had severe hypoplastic BM. 4 In the EWOG-MDS study, 355 patients with RCC were classified as either RCC with decreased cellularity (n=288) or RCC with increased or normal cellularity (n=67). 5 Because the RCMD/RCC ratio (13/58, 0.22)…”

Pediatric myelodysplastic syndromes

“…Differentiating severe aplastic anemia from hypocellular refractory cytopenia of childhood Due to limitations in the reproducibility of the diagnostic criteria and limited data on the clinical implications [29,90], the provisional diagnosis of RCC remains controversial. The WHO defines RCC as (1) dysplasia in one or more hematopoietic lineages or in at least 10 % of cells in one cell line and (2) less than 5 % blasts in the marrow [13].…”