Characterisation of children and adolescents with acute lymphoblastic leukaemia who presented without peripheral blood blasts at diagnosis.

Of 1003 children with acute lymphoblastic leukaemia (ALL), 147 (14.7%) presented without peripheral blood blasts (PBB). While absence of PBB was not independently associated with survival outcomes when compared to those with PBB, patients without PBB had distinct genetic and clinical characteristics.

Fusion-negative rhabdomyosarcoma with diffuse bony metastases and remarkable chemosensitivity.

In this report, we describe the case of an adolescent male with an unusual case of fusion-negative, paratesticular alveolar rhabdomyosarcoma who presented with spontaneous tumour lysis syndrome and diffuse bony metastases throughout the axial and appendicular skeleton with additional significant bone marrow involvement. Both spontaneous tumour lysis syndrome and diffuse bony metastases are extremely unusual for rhabdomyosarcoma. On the backbone of standard vincristine, dactinomycin and cyclophosphamide (VAC) chemotherapy, the only local control was orchiectomy at 15 weeks, with no radiation administered due to the initially diffuse nature of the disease and rapid response to chemotherapy.

The two-hit hypothesis in practice: Monozygotic twins with simultaneous hyperdiploid acute lymphoblastic leukemia.

Approximately 25% of B-cell acute lymphoblastic leukemia (B-ALL) cases are defined by hyperdiploidy, with RAS mutations occurring in 30% of hyperdiploid B-ALL patients. It is believed that hyperdiploidy is an in utero event with RAS mutations occurring postnatally, but clinical evidence of this is based on relatively few patients. We present a case of monozygotic, monochorionic twins who developed concordant hyperdiploid B-ALL with identical chromosomal gains but different RAS mutations, adding further evidence that hyperdiploidy is occurring prenatally, with RAS mutations developing postnatally.

A clinician's guide to HLA matching in allogeneic hematopoietic stem cell transplant.

Human leukocyte antigen (HLA) matching is an essential component of allogeneic hematopoietic stem cell transplant (HSCT). However, for some clinicians the biology underpinning HLA structure and function may be but a distant memory from lectures many years past, and, understanding the complexities of HLA matching can be challenging for clinicians new to the field, particularly as there have been several important advances in the field this past decade. In this review, we provide an up to date resource to educate and remind clinicians of: 1) Why HLA matching matters, including reviewing the role HLA molecules play in the adaptive immune system and the consequences of HLA mismatch.