Pitfalls in Diagnosis: JMML versus KMT2A Rearranged Juvenile AML.

Background: Lysine methyltransferase 2A (KMT2A) rearrangements are commonly found in juvenile acute myeloid leukaemia (AML). Although distinct diseases, there is a known clinical overlap between KMT2A-rearranged AML and juvenile myelomonocytic leukaemia (JMML). Both occur in infancy or early childhood and present with abnormal monocytosis. Case Report. We report a case of a 20-month-old girl, who presented with lethargy, recurrent infections, bruising, and marked hepatosplenomegaly. JMML was suspected after initial work-up, revealing an abnormal monocytosis without blast excess on immunophenotyping. The additional cytogenetic and molecular diagnostics, revealing a KMT2A rearrangement, was decisive for the confirmation of AML. Conclusion: This case highlights the challenges of diagnosing KMT2A-rearranged monocytic AML and the importance of careful morphological assessment in partnership with cytogenetic and molecular diagnostics to distinguish between KMT2A-rearranged AML and JMML. Moreover, the emerging role of molecular monitoring in AML is highlighted.

The Challenges of Crizotinib Treatment in a Child With Anaplastic Large Cell Lymphoma.

Survival in cases involving childhood malignancy is reaching nearly 80% in high-income countries, yet cancer remains one of the leading disease-related causes of death in children. In adult oncology the role of targeted therapies is established, but information regarding the use of these therapies in children is limited, largely because targeted therapies were developed in the context of adult pathologies. The few pediatric reports regarding crizotinib, an anaplastic lymphoma kinase (ALK) inhibitor, seem promising. This case of an 8-year-old male with an ALK-positive anaplastic large cell lymphoma highlights the challenges of treating children with crizotinib. Our experience with crizotinib was more challenging than described in the limited pediatric reports. Not only was the tumor response poorer than described in the reports, but a substantial amount of side-effects and practical difficulties, such as the method of administration and dosing, made management challenging. Many challenges for the use of targeted therapy in pediatric care currently persist. The limited research in pediatric populations leaves uncertainty regarding efficacy and short- and long-term side effects as well as practical difficulties. Despite a clear underlying biological rationale for certain targeted therapies, their contribution toward improving the outcome of childhood cancer remains largely unclear.

The role of nocturnal pulse oximetry in the screening for obstructive sleep apnea in obese children and adolescents.

BACKGROUND AND AIM: Obesity is a known risk factor for the development of obstructive sleep apnea (OSA) in children. Early screening is essential because of the possible complications associated with OSA. At present, the gold standard for diagnosing OSA is polysomnography, which however has multiple limitations. The aim of this study is to examine the role of nocturnal oximetry as a screening tool for OSA in obese children and adolescents. MATERIALS AND METHODS: This retrospective study included obese children who underwent a polysomnography at the Antwerp University Hospital between November 2010 and May 2014. Their oximetries were scored manually, blinded for the polysomnography results, according to Brouilette et al. OSA was defined as an obstructive apnea-hypopnea index (oAHI) ≥ 2 on polysomnography. RESULTS: This study included 130 obese patients (38% boys, mean age 12 years). Polysomnography results determined 44 patients (34%) with a diagnosis of OSA. Oximetry results classified 16 patients as positive, 43 as negative, and 71 as inconclusive. Further analysis of the positive and negative oximetry results showed a sensitivity and specificity of 58% and 88%, respectively, with a negative and positive predictive value of 81% and 69%, respectively. A second analysis, using the oxygen desaturation index, showed inferior results in comparison to the score attained by Brouillette (sensitivity 57%, specificity 73%). CONCLUSIONS: These results suggest that oximetry alone is insufficient as a screening tool for OSA in obese children. Other screening methods need to be explored in the future.