Role of neuroimaging in children with acute lymphoblastic leukemia and central nervous system involvement at diagnosis

How Cancer Harms the Developing Brain: Long-Term Outcomes in Pediatric Cancer Survivors

Survival rates for pediatric cancer are improving, resulting in a rising need to understand and address long-term sequelae. In this narrative review, we summarize the effects of cancer and its treatment on the developing brain, with a focus on neurocognitive function in leukemia and pediatric brain tumor survivors. We then discuss possible mechanisms of brain injury and management considerations.

Intracranial residual lesions following early intensification in a patient with T-cell acute lymphoblastic leukemia: a case report

BACKGROUND

T-cell acute lymphoblastic leukemia (T-ALL) tends to involve central nervous system (CNS) infiltration at diagnosis. However, cases of residual CNS lesions detected at the end of induction and post early intensification have not been recorded in patients with T-ALL. Also, the ratio and prognosis of patients with residual intracranial lesions have not been defined.

CASE PRESENTATION

A 9-year-old boy with T-ALL had multiple intracranial tumors, which were still detected post early intensification. To investigate residual CNS lesions, we used 11C-methionine (MET)-positron emission tomography. Negative MET uptake in CNS lesions and excellent MRD status in bone marrow allowed continuing therapies without hematopoietic cell transplantation.

CONCLUSIONS

In cases with residual lesions on imaging studies, treatment strategies should be considered by the systemic response, direct assessment of spinal fluid, along with further development of noninvasive imaging methods in CNS. Further retrospective or prospective studies are required to determine the prognosis and frequency of cases with residual intracranial lesions after induction therapy.

A Scoping Review of Otologic Manifestations of Hematologic Malignancies

OBJECTIVE

To examine the otologic and neurotologic symptoms, physical examination findings, and imaging features secondary to hematologic malignancies.

METHODS

Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, databases, including PubMed, Scopus, and CINAHL, were searched for articles including patients with otologic manifestations of leukemia, lymphoma and multiple myeloma. Data collected included patient and study demographics, specific hematologic malignancy, timing and classification of otologic symptoms, physical examination findings, imaging features and methods of diagnosis. Pooled descriptive analysis was performed.

RESULTS

Two hundred seventy-two articles, of which 255 (93.8%) were case reports and 17 (6.2%) were case series, reporting on 553 patients were identified. Otologic manifestations were reported on 307 patients with leukemia, 204 patients with lymphoma and 42 patients with multiple myeloma. Hearing loss and unilateral facial palsy were the most common presenting symptoms for 111 reported subjects with leukemia (n = 46, 41.4%; n = 43, 38.7%) and 90 with lymphoma (n = 38, 42.2%; n = 39, 43.3%). Hearing loss and otalgia were the most common presenting symptoms for 21 subjects with multiple myeloma (n = 10, 47.6%; n = 6, 28.6%). Hearing loss and unilateral facial palsy were the most common otologic symptoms indicative of relapse in subjects with leukemia (n = 14, 43.8%) and lymphoma (n = 5, 50%).

CONCLUSION

Hearing loss, facial palsy, and otalgia might be the first indication of a new diagnosis or relapse of leukemia, lymphoma, or multiple myeloma. Clinicians should have a heightened level of suspicion of malignant etiologies of otologic symptoms in patients with current or medical histories of these malignancies.

Facial Nerve Palsy in a Young Patient With Acute Lymphoblastic Leukemia Possibly Induced by Herpes Virus Reactivation in the Facial Nerve

Facial palsy in acute lymphoblastic leukemia (ALL) patients is diagnosed as tumor cell invasion of the central nervous system (CNS) following the ALL guidelines. Facial palsy in a 6-year-old ALL patient was diagnosed as leukemia cell invasion into the CNS by hemato-oncologists. Pretreatment magnetic resonance image (MRI) revealed gadolinium enhancement of the first genu and meatal portion of the facial nerve. After chemotherapy, although the ALL tumor cells disappeared from both the blood and the cerebrospinal fluid, and the facial palsy resolved, a posttreatment MRI showed no change in terms of enhancement of the facial nerve. These findings indicated the possibility of herpetic viral reactivation in the geniculate ganglion of the facial nerve. We must be aware and discuss with hemato-oncologists the possibility that not only tumor cell invasion into the CNS, in accordance with the guidelines, but also that herpetic virus reactivation arising in the facial nerve may be causes of facial palsy.

Integrin α6-Targeted Molecular Imaging of Central Nervous System Leukemia in Mice

Central nervous system leukemia (CNS-L) is caused by leukemic cells infiltrating into the meninges or brain parenchyma and remains the main reason for disease relapse. Currently, it is hard to detect CNS-L accurately by clinically available imaging models due to the relatively low amount of tumor cells, confined blood supply, and the inferior glucose metabolism intensity. Recently, integrin α6-laminin interactions have been identified to mediate CNS-L, which suggests that integrin α6 may be a promising molecular imaging target for the detection of CNS-L. The acute lymphoblastic leukemia (ALL) cell line NALM6 stabled and transfected with luciferase was used to establish the CNS-L mouse model. CNS-L-bearing mice were monitored and confirmed by bioluminescence imaging. Three of our previously developed integrin α6-targeted peptide-based molecular imaging agents, Cy5-S5 for near-infrared fluorescence (NIRF), Gd-S5 for magnetic resonance (MR), and ¹⁸F-S5 for positron emission tomography (PET) imaging, were employed for the molecular imaging of these CNS-L-bearing mice. Bioluminescence imaging showed a local intensive signal in the heads among CNS-L-bearing mice; meanwhile, Cy5-S5/NIRF imaging produced intensive fluorescence intensity in the same head regions. Moreover, Gd-S5/MR imaging generated superior MR signal enhancement at the site of meninges, which were located between the skull bone and brain parenchyma. Comparatively, MR imaging with the clinically available MR enhancer Gd-DTPA did not produce the distinguishable MR signal in the same head regions. Additionally, ¹⁸F-S5/PET imaging also generated focal radio-concentration at the same head regions, which generated nearly 5-times tumor-to-background ratio compared to the clinically available PET radiotracer ¹⁸F-FDG. Finally, pathological examination identified layer-displayed leukemic cells in the superficial part of the brain parenchyma tissue, and immunohistochemical staining confirmed the overexpression of the integrin α6 within the lesion. These findings suggest the potential application of these integrin α6-targeted molecular imaging agents for the accurate detection of CNS-L.

Management of CNS Disease in Pediatric Acute Lymphoblastic Leukemia

PURPOSE OF REVIEW

The treatment of acute lymphoblastic leukemia (ALL) is one of the success stories of pediatric oncology, but challenges and questions remain, including the optimal approach to the treatment of central nervous system (CNS) leukemia. It is unclear why some children with ALL develop CNS leukemia and others do not, and there remains debate regarding optimal regimens for prophylaxis, upfront treatment, and the treatment of CNS relapses. These topics are especially important since both cranial radiation therapy (CRT) and intensive intrathecal therapy carry risks of both short- and long-term adverse effects. In this review, we aim to identify areas of ongoing debate on this topic, review the biology of CNS leukemia, and summarize clinical trial data that address some of these questions.

RECENT FINDINGS

Both retrospective and meta-analyses have demonstrated that few patients with ALL benefit from CRT as a component of CNS-directed treatment for de novo disease, allowing cooperative groups to greatly limit the number of patients undergoing CRT as part of their initial ALL regimens. More recent efforts are focusing on how best to assay for low levels of CNS disease at the time of diagnosis, as well as the biological drivers that may result in CNS leukemia in certain patients. Progress remains to be made in the identification and treatment of CNS leukemia in pediatric ALL. Advancements have occurred to limit the number of children undergoing CRT, but much has yet to be learned to better understand the biology of and risk factors for CNS leukemia, and novel approaches are required to approach CNS relapse of ALL.

A narrative review of central nervous system involvement in acute leukemias

Acute leukemias (both myeloid and lymphoblastic) are a group of diseases for which each year more successful therapies are implemented. However, in a subset of cases the overall survival (OS) is still exceptionally low due to the infiltration of leukemic cells in the central nervous system (CNS) and the subsequent formation of brain tumors. The CNS involvement is more common in acute lymphocytic leukemia (ALL), than in adult acute myeloid leukemia (AML), although the rates for the second case might be underestimated. The main reasons for CNS invasion are related to the expression of specific adhesion molecules (VLA-4, ICAM-1, VCAM, L-selectin, PECAM-1, CD18, LFA-1, CD58, CD44, CXCL12) by a subpopulation of leukemic cells, called “sticky cells” which have the ability to interact and adhere to endothelial cells. Moreover, the microenvironment becomes hypoxic and together with secretion of VEGF-A by ALL or AML cells the permeability of vasculature in the bone marrow increases, coupled with the disruption of blood brain barrier. There is a single subpopulation of leukemia cells, called leukemia stem cells (LSCs) that is able to resist in the new microenvironment due to its high adaptability. The LCSs enter into the arachnoid, migrate, and intensively proliferate in cerebrospinal fluid (CSF) and consequently infiltrate perivascular spaces and brain parenchyma. Moreover, the CNS is an immune privileged site that also protects leukemic cells from chemotherapy. CD56/NCAM is the most important surface molecule often overexpressed by leukemic stem cells that offers them the ability to infiltrate in the CNS. Although asymptomatic or with unspecific symptoms, CNS leukemia should be assessed in both AML/ALL patients, through a combination of flow cytometry and cytological analysis of CSF. Intrathecal therapy (ITT) is a preventive measure for CNS involvement in AML and ALL, still much research is needed in finding the appropriate target that would dramatically lower CNS involvement in acute leukemia.

The diagnostic and prognostic value of MRI in central nervous system involvement of acute myeloid leukemia: a retrospective cohort of 84 patients

ABSTRACT Objective: To assess the diagnostic and prognostic value of magnetic resonance imaging (MRI) in Acute Myeloid Leukemia (AML) complicated with central nervous system leukemia (CNSL). Methods: A total of 84 patients with AML and confirmed of CNSL from January 2010 to September 2019 were selected and underwent MRI scan. We retrospectively analyzed their MRI findings, summarized the imaging features of AML central infiltration, and assessed the guiding significance of MRI on diagnosis and prognosis of this disease. Results: A total of 52 patients (61.90%, 52/84) had abnormal MRI findings, of which 31 cases clearly indicated intracranial infiltration of leukemia. Among the 31 patients, the most common site of infiltration is parenchyma (19/31). Most MRI of these patients showed multiple lesions with low T1 signal and high T2 signal, which were more obvious on enhanced scan. Sensitivity of MRI in diagnosing AML central infiltration was 36.90%. Despite of its low sensitivity, it still had superior diagnostic value on some patients with false-negative CSF. The median disease-free survival (DFS) and overall survival (OS) time of patients with MRI clearly indicated central invasion were 4 and 9 months, respectively. But there was no significant difference in survival analysis compared with MRI negative patients (including abnormal but non-invasive). Conclusion: MRI manifestation of central infiltration in AML patients has certain characteristic findings, which is helpful to improve the diagnostic efficiency. Prognosis of MRI positive patients is relatively worse than that of MRI negative patients however there is no siginificant difference.

Acute monocytic leukemia presenting as generalized lymphadenopathy and skin rash in a toddler: highlighting the clinicopathologic mimics

Acute myeloid leukemia (AML) is the fifth most common malignancy in children. Extramedullary involvement in acute myeloid leukemia is rare and can be seen in soft tissues, central nervous system, skin and lymphoreticular organs. The clinical presentations can often be non-specific and hence, the diagnosis can be very challenging, especially in cases without a prior hematologic diagnosis. We report a case of pediatric acute monocytic leukemia presenting with generalized lymphadenopathy and cutaneous rash. Fine-needle aspiration was performed from the lymph nodes and a cytologic diagnosis of infiltration by a lymphoreticular malignancy was suggested. Peripheral blood, bone marrow and cerebrospinal fluid involvement were noted subsequently. Flow cytometry on the bone marrow aspirate confirmed a diagnosis of acute monocytic leukemia. The index case besides highlighting an uncommon presentation of acute monocytic leukemia in a toddler, also emphasizes the need to consider acute monocytic leukemia as a cytomorphologic differential in such presentations.

The spectrum of acute central nervous system symptoms during the treatment of childhood acute lymphoblastic leukaemia

BACKGROUND

Children with central nervous system (CNS) toxicity during therapy for acute lymphoblastic leukaemia (ALL) are at risk for treatment modifications, long-term sequelae and even higher mortality. A better understanding of CNS symptoms and their complications improves the potential to prevent and treat them.

METHODS

Patient files from 649 children treated with Nordic Society of Pediatric Hematology and Oncology ALL92 and ALL2000 protocols in Finland were reviewed retrospectively for any acute CNS symptom. Detailed data on symptoms, examinations and treatment of the underlying CNS complications were collected from the medical records. Disease-related and outcome data were retrieved from the Nordic leukaemia registry.

RESULTS

Altogether, 13% (86) of patients with ALL had acute CNS symptoms. Most symptoms (64%) occurred during the first 2 months of therapy. Posterior reversible encephalopathy syndrome was the most frequent complication (4.5%). Cerebrovascular events were diagnosed in 10 cases (1.6%), while methotrexate-related stroke-like syndrome (SLS) was observed in only one patient (0.2%). CNS symptoms due to systemic or unclear conditions, especially sepsis, were important for differential diagnosis. CNS leukaemia was associated with CNS symptoms (hazard ratio [HR] = 4.03; P = .003), and epilepsy was a common sequel of CNS complications (19%).

CONCLUSIONS

Acute CNS symptoms are common during ALL therapy, occurring mainly during the first 2 months of treatment. Patients with CNS leukaemia at diagnosis are at a higher risk for CNS toxicity. Despite intensive CNS-directed methotrexate treatment, SLS was diagnosed extremely rarely in our series.

Posterior reversible encephalopathy syndrome in children with acute lymphoblastic leukemia: Clinical characteristics, risk factors, course, and outcome of disease

BACKGROUND

Posterior reversible encephalopathy syndrome (PRES) is a distinct entity with incompletely known predisposing factors. The aim of this study is to describe the incidence, risk factors, clinical course, and outcome of PRES in childhood acute lymphoblastic leukemia (ALL).

PROCEDURE

Patients aged 1.0 to 17.9 years diagnosed with ALL from July 2008 to December 2015 and treated according to the Nordic Society of Pediatric Hematology and Oncology (NOPHO) ALL2008 protocol were included. Patients with PRES were identified in the prospective NOPHO leukemia toxicity registry, and clinical data were collected from the medical records.

RESULTS

The study group included 1378 patients, of whom 52 met the criteria for PRES. The cumulative incidence of PRES at one month was 1.7% (95% CI, 1.1-2.5) and at one year 3.7% (95% CI, 2.9-4.9). Older age (hazard ratios [HR] for each one-year increase in age 1.1; 95% CI, 1.0-1.2, P = 0.001) and T-cell immunophenotype (HR, 2.9; 95% CI, 1.6-5.3, P = 0.0005) were associated with PRES. Central nervous system (CNS) involvement (odds ratios [OR] = 2.8; 95% CI, 1.2-6.5, P = 0.015) was associated with early PRES and high-risk block treatment (HR = 2.63; 95% CI, 1.1-6.4, P = 0.033) with late PRES. At follow-up of the PRES patients, seven patients had epilepsy and seven had neurocognitive difficulties.

CONCLUSION

PRES is a neurotoxicity in the treatment of childhood ALL with both acute and long-term morbidity. Older age, T-cell leukemia, CNS involvement and high-risk block treatment are risk factors for PRES.

Application of Fluorescence In Situ Hybridization on Cerebrospinal Fluid Cytospins for the Detection of Residual Leukemic Cells in Patients With Childhood Acute Lymphoblastic Leukemia

OBJECTIVES

Diagnosis of central nervous system involvement in acute lymphoblastic leukemia (ALL) requires morphologic expertise; therefore, we evaluated interphase fluorescence in situ hybridization (iFISH) of cerebrospinal fluid (CSF) cytospin preparations as a potential complementary test.

METHODS

Twenty-three CSF cytospin specimens from 13 pediatric patients with ALL were included. iFISH probes detecting BCR-ABL1, ETV6-RUNX1, and KMT2A rearrangement and CDKN2A deletion, which were present at initial diagnosis, were used on follow-up CSF cytospin specimens and were compared with cytology.

RESULTS

Seventeen (73.9%) follow-up specimens showed concordant results between iFISH and cytology. Two (8.7%) samples with discordant results were positive by iFISH but not by cytology; one (4.3%) was positive only by cytology. In the remaining three (13.0%) specimens, too few cells were available for cytology, whereas iFISH interpretation was possible.

CONCLUSIONS

iFISH of CSF cytospin preparations improves malignant cell detection in pediatric ALL.

Facial paralysis as a presenting symptom of infant leukemia: A case report and literature review

RATIONALE

Facial paralysis as the initial clinical presentation of infant leukemia (IL) is rare, and the rate of its misdiagnosis is high. Identifying the clinical characteristics of IL with facial paralysis as the initial symptom is necessary to improve the understanding of the causes of facial paralysis and IL.

PATIENT CONCERNS

A 10-month-old infant had facial paralysis and recurrent fever. He was misdiagnosed as having bacterial meningitis for >2 months.

DIAGNOSES

The infant was diagnosed as having acute monocytic leukemia (M5) with central infiltration based on examinations of the bone marrow and cerebrospinal fluid by flow cytometry.

INTERVENTIONS

Before the diagnosis of leukemia, the patient was given meropenem, ceftriaxone, vancomycin, and ampicillin successively for anti-infective treatment for 2 months, and dexamethasone for several days. But he gave up further treatment after confirmed diagnosis.

OUTCOMES

Our patient discontinued treatment and discharged. From literature review, there were 6 cases (including this case) of IL with facial paralysis as the initial symptom. 80% of patients were misdiagnosis and treated with a corticosteroid in the early stage, and the mortality was 33.3%.

LESSONS

The clinical symptoms of IL with facial paralysis are not typical, with a high rate of misdiagnosis. When the cause of facial paralysis is unknown or the advance treatment effect is poor, tumor diseases should be considered. Corticosteroids should be carefully administered to children with facial paralysis.

Anti-leukemic treatment-induced neurotoxicity in long-term survivors of childhood acute lymphoblastic leukemia: impact of reduced central nervous system radiotherapy and intermediate- to high-dose methotrexate

The aim of the study was to evaluate the long-term neurodevelopmental consequences of currently applied acute lymphoblastic leukemia (ALL) therapy containing chemotherapy alone or combined with 12 Gy radiotherapy. Seventy-nine children aged 6.3-21.7 years diagnosed with ALL and treated according to ALL IC-BFM 2002 have been studied. The control group consisted of 23 children newly diagnosed with ALL. We assessed subcortical gray matter volume using automatic MRI segmentation and cognitive performance to identify differences between three therapeutic schemes and patients prior to treatment. Irradiated patients had smaller selected subcortical volumes than those treated with chemotherapy alone and than the controls, while the chemotherapy group had similar volumes as the control one. In neurocognitive assessment, irradiated children performed worse in major domains than the control group. There were no significant results for patients after high dose chemotherapy without radiotherapy. There was a significant relationship between full scale IQ together with verbal learning and volumes of hippocampus, amygdala, and pallidum. In all children treated for ALL, both decreased volume of selected subcortical structures and cognitive impairment were observed, especially in children who were irradiated.

RUNX1-RUNX1T1-positive acute myeloid leukaemia presenting as bilateral proptosis and multiple cranial nerve palsy

We describe a unique presentation of acute myeloid leukaemia (AML) with myeloid sarcoma (MS), manifested as proptosis with multiple cranial nerve palsies in a 9-year-old boy. MRI of the brain revealed multiple enhancing lesions and bilateral mastoiditis, in addition to sagittal sinus thrombosis. Peripheral blood smear demonstrated blasts showing Auer rods. Bone marrow examination confirmed the diagnosis of AML. PCR was positive for RUNX1-RUNX1T1. Neurological deficits improved with induction chemotherapy for AML. Extramedullary MS can present simultaneously with or antedate AML. Common genetic aberrations include t(8;21) and inv(16). Therapy is akin to AML. An effect of MS on survival outcomes is variable.

Central hypothyroidism in a pediatric case of primary acute monoblastic leukemia with central nervous system infiltration: A case report

RATIONALE

Central nervous system (CNS) leukemia is a frequent diagnosis in pediatric acute myeloblastic leukemia (AML) and includes neural symptoms. However, CNS leukemia is rarely associated with central hypsothyroidism.

PATIENT CONCERNS AND DIAGNOSES

A 2-year-old female with AML with MLL rearrangement presented with CNS infiltration. Laboratory tests suggested the presence of central hypothyroidism (thyroid-stimulating hormone [TSH]: 0.48 mIU/ml, normal range 0.7-6.4 mIU/ml; serum free thyroxine [FT4]: 0.62 ng/dl, normal range 0.8-2.2 ng/dl; free triiodothyronine: 1.57 pg/ml, normal range 2.7-5.6 pg/ml). Magnetic resonance imaging detected no lesions in the hypothalamus, pituitary, or thyroid.

INTERVENTIONS AND OUTCOMES

Levothyroxine (2.5 mg/kg/day) was administered together with chemotherapy and intrathecal injection of methotrexate, cytarabine, and hydrocortisone into the cerebrospinal fluid. The FT4 concentration increased after levothyroxine treatment, but later decreased after relapse of CNS leukemia. The TSH concentrations remained low. After remission of CNS leukemia, the TSH and FT4 concentrations quickly recovered to their normal ranges.

LESSONS

We believe that the CNS leukemia directly affected TSH and thyroid hormone secretion in our patient.