Myelodysplastic syndrome with partial deletion of the long arm of chromosome 5: first report of a case in a child

Rare Hematologic Malignancies and Pre-Leukemic Entities in Children and Adolescents Young Adults

There are a variety of rare hematologic malignancies and germline predispositions syndromes that occur in children and adolescent young adults (AYAs). These entities are important to recognize, as an accurate diagnosis is essential for risk assessment, prognostication, and treatment. This descriptive review summarizes rare hematologic malignancies, myelodysplastic neoplasms, and germline predispositions syndromes that occur in children and AYAs. We discuss the unique biology, characteristic genomic aberrations, rare presentations, diagnostic challenges, novel treatments, and outcomes associated with these rare entities.

5q- syndrome in a child with slowly progressive pancytopenia: a case report and review of the literature

5q- syndrome is a rare myelodysplastic process occurring predominately in middle aged to elderly women. In children, myelodysplasia of all types is rare and 5q- syndrome is exceptionally rare. Only 6 cases of 5q- associated myelodysplasia have been reported in children and all 6 cases had blast counts >5% and/or additional cytogenetic abnormalities. We report a case of 5q- syndrome in a girl who presented with macrocytosis and intermittent pancytopenia at age 5. Cytogenetic studies at age 8 revealed a large interstitial deletion of chromosome 5q without other cytogenetic abnormalities. The patient was clinically stable until age 11, when she became transfusion dependent and severely neutropenic. Subsequently, she underwent a successful unrelated cord blood transplant. To our knowledge, this is the first reported pediatric case meeting the strict criteria for 5q- syndrome.

A pediatric approach to the WHO classification of myelodysplastic and myeloproliferative diseases

Myelodysplastic and myeloproliferative disorders are rare in childhood and there is no widely accepted system for their diagnosis and classification. We propose minimal diagnostic criteria and a simple classification scheme which, while based on accepted morphological features and conforming with the recent suggestions of the WHO, allows for the special problems of myelodysplastic diseases in children. The classification recognizes three major diagnostic groups: (1) juvenile myelomonocytic leukemia (JMML), previously named chronic myelomonocytic leukemia (CMML) or juvenile chronic myeloid leukemia (JCML); (2) myeloid leukemia of Down syndrome, a disease with distinct clinical and biological features, encompassing both MDS and AML occurring in Down syndrome; and (3) MDS occurring both de novo and as a complication of previous therapy or pre-existing bone marrow disorder (secondary MDS). The main subtypes of MDS are refractory cytopenia (RC) and refractory anemia with excess of blasts (RAEB). It is suggested retaining the subtype of RAEB-T with 20-30% blasts in the marrow until more data are available. Cytogenetics and serial assessments of the patients are essential adjuncts to morphology both in diagnosis and classification.

Hyperdiploid karyotype in a childhood MDS patient

We present a rare case of a paediatric myelodysplastic syndrome (MDS) with congenital anomalies (frontal bossing and premature closure of anterior fontanelle). The case showed the clinical and biological features of a refractory anaemia excess blasts (RAEB). Bone marrow (BM) cytogenetics demonstrated a hyperdiploid karyotype, with several numerical abnormalities and unidentified rearrangements. Fluorescence in situ hybridization (FISH) using chromosome specific alpha-satellite and whole chromosome-specific painting probes verified the hyperdiploid karyotype, and confirmed the origin of the unknown markers and rearrangements more reliably than would be possible using conventional cytogenetic techniques.

5q- in a child with refractory anemia with excess blasts: similarities to 5q- syndrome in adults

A 19-month-old boy was referred to our institution because of chronic macrocytic anemia and severe thrombocytopenia. At age 17 months, he had developed petechiae. He had a leukocyte count of 4.4 x 10(9)/L, hemoglobin concentration of 7.9 g/dL, packed cell volume of 21%, mean corpuscular volume of 101 fL, and platelet count of 19 x 10(9)/L. At the time of referral, a bone marrow aspirate and biopsy revealed myelodysplastic changes that included megakaryocytic hyperplasia with hypolobated megakaryocytes, megaloblastoid erythropoiesis, 12% blast cells, and bone marrow fibrosis; the diagnosis was refractory anemia with excess blasts (RAEB). Cytogenetic analysis showed the following abnormalities: 47, XY, inv(3)(p21q25), del(5)(q22q31), +21/46, XY. By dinucleotide polymorphism analysis, the 5q22-q31 loci were normal in peripheral blood granulocytes. Because of severe thrombocytopenia that became refractory to platelet transfusions and because of possible progression to leukemia, the patient received an unrelated-donor bone marrow transplant. Recovery was complicated by a visceral fungal infection, but the patient now has normal, fully reconstituted bone marrow function. This patient is the youngest to be reported with RAEB and a 5q- anomaly accompanied by thrombocytopenia, megakaryocytic hyperplasia with hypolobated megakaryocytes, and macrocytic anemia with megaloblastoid erythropoiesis, similar to "5q- syndrome" in adults.

Myelodysplastic syndromes in childhood--classification, epidemiology, and treatment

Much of the applied terminology of myelodysplastic syndromes (MDS) in childhood is confusing and not mutually exclusive. It is therefore proposed that the FAB classification of MDS is used in children in order to improve diagnostic precision and to facilitate epidemiologic, clinical, and therapeutic comparisons. The true incidence of childhood MDS is unknown but the rate may approximate the incidence of acute myelogenous leukemia. A pooled analysis of eight larger series representing 110 children less than 15 years old at diagnosis with de novo MDS classified according to the FAB recommendations showed that the more aggressive subtypes dominated, which partly may reflect that the less advanced cases are underdiagnosed. The median age at presentation was 6.0 years. The male/female ratio was 1.6. Monosomy 7 was the most frequent cytogenetic abnormality. The median survival was 13 months and the probability of survival three years from diagnosis was 16%. Spontaneous remission may be observed very infrequently. Allogeneic bone marrow transplantation (BMT) represents the only potentially curative treatment. The survival rate three years after BMT is about 50%. Major differences between childhood and adult MDS exist with respect to the distribution of FAB subgroups, the rate of progression, and the cytogenetic findings. The literature on MDS in children is still sparse and there is an obvious need for more studies designed to determine the incidence, clinical and laboratory characteristics, the natural course, and the efficacy of contemporary treatment options.