Molecular characterization of paediatric idiopathic hypereosinophilia

Updates on eosinophilic disorders

This review addresses changes and updates in eosinophilic disorders under the International Consensus Classification (ICC). The previous category of myeloid/lymphoid neoplasm with eosinophilia (M/LN-eo) and a specific gene rearrangement is changed to M/LN-eo with tyrosine kinase gene fusions to reflect the underlying genetic lesions. Two new members, M/LN-eo with ETV6::ABL1 fusion and M/LN-eo with various FLT3 fusions, have been added to the category; and M/LN-eo with PCM1::JAK2 and its genetic variants ETV6::JAK2 and BCR::JAK2 are recognized as a formal entity from their former provisional status. The updated understanding of the clinical and molecular genetic features of PDGFRA, PDGFRB and FGFR1 neoplasms is summarized. Clear guidance as to how to distinguish these fusion gene-associated disorders from the overlapping entities of Ph-like B-acute lymphoblastic leukemia (ALL), de novo T-ALL, and systemic mastocytosis is provided. Bone marrow morphology now constitutes one of the diagnostic criteria of chronic eosinophilic leukemia, NOS (CEL, NOS), and idiopathic hypereosinophilia/hypereosinophilic syndrome (HE/HES), facilitating the separation of a true myeloid neoplasm with characteristic eosinophilic proliferation from those of unknown etiology and not attributable to a myeloid neoplasm.

Acute Exacerbation of Hypereosinophilic Syndrome Complicated With Dermatitis, Enteritis, and Myositis: A Case Report

Hypereosinophilic syndrome is a disease that presents with a variety of symptoms caused by an abnormal rise in eosinophils in the blood and infiltration into various organs. Typical symptoms include skin symptoms and diarrhea. Diagnosis may be difficult because of the self-limiting phases of the disease with various symptoms. In addition, diagnosis may be delayed by the presence of rare concomitant symptoms, such as muscle pain and numbness. Here, we report the case of a 67-year-old patient with asymptomatic hypereosinophilia with chronic diarrhea, acute-onset weakness, and myalgia. We diagnosed eosinophilic gastroenteropathy, chronic urticaria, and eosinophilic myositis through multiple biopsies of the skin and colon. This case shows that chronic hypereosinophilic syndrome can be exacerbated transiently with acute symptoms and that prompt examination and treatment of hypereosinophilic syndrome based on the involved organs is recommended in a background of eosinophilia.

Diagnosis and Management of Pediatric Hypereosinophilic Syndrome

Hypereosinophilic syndrome (HES) is a diverse group of disorders characterized by peripheral blood eosinophilia of 1.5 × 10⁹/L (1,500/μL) or greater with evidence of end-organ damage attributable to eosinophilia and no other cause of the end-organ damage. The HES is rare, especially in children. This review aims to provide best practices in diagnosis and treatment of HES in children, including how to differentiate between primary and secondary causes of hypereosinophilia; how to distinguish the differences in clinical presentation, treatment, and prognosis of HES in children and adults; and how to identify key steps in the evaluation and management of HES in children.

Case Report: Pediatric myeloid/lymphoid neoplasm with eosinophilia and PDGFRA rearrangement: The first case presenting as B-lymphoblastic lymphoma

According to the latest WHO classification of hematopoietic malignancies, myeloid and lymphoid neoplasms with eosinophilia and gene rearrangements include three specific rare diseases and one provisional entity. Myeloid/lymphoid neoplasms with platelet-derived growth factor receptor alpha (PDGFRA) rearrangements are the most frequent of these disorders and are usually present in adult males with a median age of the late 40s. Patients usually have chronic eosinophilic leukemia but can occasionally manifest as acute myeloid leukemia or extramedullary T- or B-lineage lymphoblastic lymphoma. We report a case of a previously healthy 2-year-old girl who presented with a right supraorbital swelling with no associated lymphadenopathy. Peripheral blood smear evaluation at initial presentation revealed microcytic hypochromic red blood cells and leukocytosis with marked eosinophilia, occasional myelocytes, and occasional blasts. Whole-body CT scans and PET scans revealed hypermetabolic potentially lymphomatous mass in the superior medial aspect of the right orbit in addition to splenomegaly but no evidence of hypermetabolic mediastinal, hilar, abdominal, or pelvic lymph nodes. Bone marrow aspirate and biopsy revealed hypercellular bone marrow with quantitatively decreased erythroid precursors and increased granulocytic precursors with 60% of the cells being eosinophilic cells in different stages of maturation. The diagnosis of myeloid neoplasm with eosinophilia and rearrangement of PDGFRA was made following confirmation by fluorescence in situ hybridization (FISH) test for FIP1L1-PDGFRA gene fusion. An incisional biopsy of the supraorbital mass revealed B-cell lymphoblastic lymphoma (B-LBL). FISH test for FIP1L1-PDGFRA gene fusion was positive in 70% of the cells studied. Thus, the final diagnosis was B-cell lymphoblastic lymphoma arising in the setting of myeloid/lymphoid neoplasm with eosinophilia and PDGFRA rearrangement. The patient was started on imatinib with concomitant therapy for B-LBL per the Children Oncology Group (COG) standard therapy for localized B-LBL and demonstrated a favorable outcome in the 2.5-year follow-up period. To our knowledge, this is the first pediatric case of myeloid/lymphoid neoplasm with PDGFRA rearrangement presenting with synchronous myeloproliferative disease and B-LBL. We present our diagnostic and management approach of this patient and review prior relevant pediatric cases of myeloid/lymphoid neoplasms with PDGFRA rearrangement.

Elusive Diagnosis of Eosinophilic Myocarditis: A Case Series

We present 2 relevant cases of eosinophilic myocarditis (EM) in patients that presented with cardiogenic shock, one of whom received a durable ventricular assist device followed by heart transplantation, with the diagnosis of EM being made based on analysis of the excisional biopsy obtained during implantation of the ventricular assist device. The second patient was initially misdiagnosed with peripartum cardiomyopathy and underwent abortion, to later being diagnosed with EM through endomyocardial biopsy. These two cases highlight the importance of high clinical suspicion for EM based on eosinophilia, comorbidities, and presentation, as well as the value of early diagnosis and therapeutic interventions, including corticosteroids, and advanced heart failure therapies, such as mechanical circulatory support and heart transplantation.

Myeloid/Lymphoid Neoplasms with Eosinophilia and TK Fusion Genes, Version 3.2021, NCCN Clinical Practice Guidelines in Oncology

Eosinophilic disorders and related syndromes represent a heterogeneous group of neoplastic and nonneoplastic conditions, characterized by more eosinophils in the peripheral blood, and may involve eosinophil-induced organ damage. In the WHO classification of myeloid and lymphoid neoplasms, eosinophilic disorders characterized by dysregulated tyrosine kinase (TK) fusion genes are recognized as a new category termed, myeloid/lymphoid neoplasms with eosinophilia and rearrangement of PDGFRA, PDGFRB or FGFR1 or with PCM1-JAK2. In addition to these aforementioned TK fusion genes, rearrangements involving FLT3 and ABL1 genes have also been described. These new NCCN Guidelines include recommendations for the diagnosis, staging, and treatment of any one of the myeloid/lymphoid neoplasms with eosinophilia (MLN-Eo) and a TK fusion gene included in the 2017 WHO Classification, as well as MLN-Eo and a FLT3 or ABL1 rearrangement.

Loeffler's Endocarditis and Hypereosinophilic Syndrome

Loeffler's endocarditis and hypereosinophilic syndromes are a unique group of infiltrative disorders characterized by hypereosinophilia, inflammatory thrombotic, and ultimately, fibrotic involvement of the heart leading to multiple complications including valve involvement, thromboembolic phenomena, heart failure. Clinical recognition, comprehensive laboratory and multimodality imaging diagnostic workup, and early initiation of treatment have been shown to slow down the progression and promote remission. This review addresses a detailed analysis of Loeffler's endocarditis and hypereosinophilic syndromes.

Hypereosinophilia and severe bone disease in an African child: an unexpected diagnosis

Hypereosinophilic syndromes are rare in children. Sporadic, mild-severity FIP1L1-platelet-derived growth factor receptor α (PDGFRα) rearrangement cases have been reported, mainly in boys. We present the case of a 5-year-old girl referred from her African country of birth, due to severe constitutional symptoms, multifocal bone pain, headache, gastrointestinal complaints, cardiomyopathy and unexplained hypereosinophilia. She presented multiple end-organ diseases and striking bone involvement. Although she had a positive serology for Strongyloides stercoralis, extensive evaluation detected a FIP1L1-PDGFRA fusion gene. Systemic corticosteroids and low-dose imatinib were started and the child became asymptomatic. After 9 months of treatment, FIP1L1-PDGFRA was no longer detected.

Intracardiac Thrombus in Leukemia: Role of Cardiac Magnetic Resonance Imaging in Eosinophilic Myocarditis

•

EM involves acute necrotic, intermediate thrombotic, and late fibrotic stages.

•

Echocardiography is the initial modality for the diagnosis of EM.

•

EMB could miss the diagnosis if the area involved is not biopsied.

•

CMR reliably detects all three stages of EM.

Hypereosinophilic Syndrome: Hacettepe Experience

The aim was to evaluate baseline demographic, clinical, and laboratory characteristics, treatment modalities, and outcome of children with idiopathic hypereosinophilic syndrome (HES) followed up in our center. Children who fulfilled the criteria of idiopathic HES followed up at Hacettepe University Faculty of Medicine, Pediatric Hematology Department between June 2004 and October 2013 were included in this study. Medical records of all children with idiopathic HES were reviewed to obtain regarding data. The mean age of 6 children with idiopathic HES was 52.8±44.3 months (13 to 132 mo) at diagnosis. Among 6 children with idiopathic HES; 2 had pulmonary involvement; 1 had cardiac and pulmonary involvement and splenomegaly; 1 had cardiac involvement and hepatosplenomegaly; 1 had cardiac and central nervous system involvement; and 1 had skin involvement. The mean follow-up duration was 36.5±31.4 months. Methyl prednisolone (MP) was used for the first-line therapy. Complete response was achieved with MP in 3 children. All steroid responsive children are alive; whereas 3 children who did not respond to MP had expired. In conclusion, cardiac and pulmonary involvement is the major causes of mortality in HES. Resistance to steroid therapy indicates poor prognosis.

Biventricular thrombus in hypereosinophilic syndrome presenting with shortness of breath

A 48 years old male presented to clinic with 12 months of low grade fever with shortness of breath which has progressively worsened with no associated weight loss, night sweats or loss of appetite. There was no prior history of chronic illness before the current illness. Laboratory workup revealed a high white blood cell count with predominant eosinophils. Chest X-ray was normal. Transthoracic echocardiography and Cardiac Magnetic Resonance showed biventricular thrombi. On further extensive workup the findings were consistent with hypereosinophilic syndrome. The patient was started on oral steroids, hydroxyurea, imatanib mesylate and oral anticoagulation. The patient responded to the treatment with complete resolution of his symptoms over the course of few months. The repeat Echocardiogram after a year showed normal left ventricular systolic and diastolic function with complete resolution of biventricular thrombi.

A Case of Idiopathic Hypereosinophilic Syndrome Causing Mitral Valve Papillary Muscle Rupture

Idiopathic Hypereosinophilic Syndrome (IHES) is a rare disease that can be difficult to diagnose as the differential is broad. This disease can cause significant morbidity and mortality if left untreated. Our patient is a 17-year-old adolescent female who presented with nonspecific symptoms of abdominal pain and malaise. She was incidentally found to have hypereosinophilia of 16,000 on complete blood count and nonspecific colitis and pulmonary edema on computed tomography. She went into cardiogenic shock due to papillary rupture of her mitral valve requiring extreme life support measures including intubation and extracorporal membrane oxygenation (ECMO) as well as mitral valve replacement. Pathology of the valve showed eosinophilic infiltration as the underlying etiology. The patient was diagnosed with IHES after the exclusion of infectious, rheumatologic, and oncologic causes. She was treated with steroids with improvement of her symptoms and scheduled for close follow-up. In general patients with IHES that have cardiac involvement have poorer prognoses.

Hypereosinophilia in childhood acute lymphoblastic leukaemia at diagnosis: report of 2 cases and review of the literature

Hypereosinophilia as first clinical presentation has rarely been reported in paediatric acute lymphoblastic leukaemia. It is commonly associated with specific cytogenetic abnormalities. Although eosinophilia is considered a reactive, non-neoplastic epiphenomenon, it adversely affects patient outcomes, both in children and adults. We describe herewith two paediatric patients who had marked eosinophilia at onset of acute lymphoblastic leukaemia. We point out the importance of a correct differential diagnosis in persistent, unexplained peripheral hypereosinophilia. Clinicians should keep in mind that eosinophilia can be part of the overall pattern of acute leukaemia and therefore needs to be properly investigated. We also provide some recommendations for an appropriate approach to hypereosinophilia - related morbidities.

Loeffler's endocarditis with biventricular mural thrombi

A 42-year-old man presented to clinic with 1-week history of cough, malaise, loss of appetite and fever. Symptoms started acutely with cough and generalised weakness followed by fever, chills, nausea, vomiting and diarrhoea. He has been healthy before with no chronic illnesses. Further workup disclosed, leucocytosis with 87% eosinophilia, bilateral lung infiltrate, deep venous thrombosis, pulmonary embolism and both right and left biventricular mural thrombi. Extensive workup was done and was consistent with hypereosinophilic syndrome, which explained all his clinical findings. The patient was started on high-dose steroids and responded very well with a complete resolution of symptoms over the course of a few weeks.

Hypereosinophilic syndrome associated with ulcerative colitis presenting with recurrent Loeffler's endocarditis and left ventricular thrombus treated successfully with immune suppressive therapy and anticoagulation

We reported a case of a 28-year-old Caucasian woman with hypereosinophilic syndrome (HES) associated with ulcerative colitis who presented on separate occasions with Loeffler's endocarditis. She was admitted in 2008 with fever, headache, confusion and visual loss. Diagnostic workup uncovered an eosinophilia of 3.1×10⁹/L and major ECG abnormalities. Subsequent echocardiography revealed left ventricular wall motion abnormalities with mural thrombus. MRI brain scan showed multiple white matter lesions consistent with acute infarcts. She recovered rapidly with corticosteroids and anticoagulation. Four years later she re-presented with headache, fatigue and an eosinophilia of 13.4×10⁹/L. This occurred 3 months after cessation of immunosuppression and within 12 months of total colectomy for fulminant ulcerative colitis. Echocardiography was suggestive of hypereosinophilic endomyocardial fibrosis with left ventricular thrombus. Anticoagulation and corticosteroids were resumed with good effect. This report highlights the findings, treatment and outcome of ulcerative colitis-associated HES manifesting as recurrent Loeffler's endocarditis.

Lymphoproliferative disorders associated with hypereosinophilia

Hypereosinophilia, defined as peripheral blood eosinophil counts > 1,500/μL, may complicate the course of various lymphoproliferative disorders. Among these, Hodgkin lymphoma (HL) and certain peripheral T-cell lymphomas (PTCLs) derived from CD4 cells, including Sezary syndrome (SS), adult T-cell leukemia/lymphoma (ATLL), and angioimmunoblastic T-cell lymphoma (AITL), are most commonly associated with increased reactive eosinophilopoiesis. Rarely, marked hypereosinophilia (HE) may occur in the setting of acute B-cell lymphoblastic leukemia, with a substantial impact on disease course. The mechanisms leading to blood and tissue eosinophilia in the setting of lymphoproliferative disorders, as well as the clinical complications and prognostic implications of hypereosinophilia, are discussed in this review.

Contemporary consensus proposal on criteria and classification of eosinophilic disorders and related syndromes

Eosinophilia is an important indicator of various neoplastic and nonneoplastic conditions. Depending on the underlying disease and mechanisms, eosinophil infiltration can lead to organ dysfunction, clinical symptoms, or both. During the past 2 decades, several different classifications of eosinophilic disorders and related syndromes have been proposed in various fields of medicine. Although criteria and definitions are, in part, overlapping, no global consensus has been presented to date. The Year 2011 Working Conference on Eosinophil Disorders and Syndromes was organized to update and refine the criteria and definitions for eosinophilic disorders and to merge prior classifications in a contemporary multidisciplinary schema. A panel of experts from the fields of immunology, allergy, hematology, and pathology contributed to this project. The expert group agreed on unifying terminologies and criteria and a classification that delineates various forms of hypereosinophilia, including primary and secondary variants based on specific hematologic and immunologic conditions, and various forms of the hypereosinophilic syndrome. For patients in whom no underlying disease or hypereosinophilic syndrome is found, the term hypereosinophilia of undetermined significance is introduced. The proposed novel criteria, definitions, and terminologies should assist in daily practice, as well as in the preparation and conduct of clinical trials.

Does hypereosinophilic syndrome precede common B acute lymphoblastic leukaemia in childhood? A case report

Hypereosinophilic syndrome (HES) and the association of hypereosinophilia with acute lymphoblastic leukaemia (ALL) are both rare in children. Some acute myelogenous leukaemias can present with eosinophilia, but the relationship between HES and ALL is not well known and is rarer than the relationship between HES and acute myelogenous leukaemia. Patients are diagnosed with HES when no cause is found to explain the eosinophilia leading to end organ damage. For this reason, it is recommended that patients presenting with hypereosinophilia be carefully assessed to exclude any malignant clonal proliferation. HES may present with severe clinical manifestations such as high leucocyte count, anaemia, thrombocytopaenia, hepatosplenomegaly or cardiac and neurological involvement, all of which are primarily features of myeloproliferative disorders. Some patients with HES can develop chronic eosinophilic leukaemia. Successful treatment of HES with agents used in chronic myeloid leukaemia supports the idea that HES can be a chronic myeloid disorder. There are few cases reporting an association between ALL and hypereosinophilia that precedes or is concomitant with ALL. Here we report the case of a 14-year-old girl who developed common B ALL 7 months after diagnosis and treatment of HES. Interestingly, eosinophilia was not concomitant with the diagnosis of ALL.