Follow-up of pediatric patients treated by IVIG for Langerhans cell histiocytosis (LCH)-related neurodegenerative CNS disease

Juvenile xanthogranuloma manifesting with LCH-associated neurodegenerative disease-like radiological findings

Here, we describe two patients with juvenile xanthogranuloma (JXG) manifesting with Langerhans cell histiocytosis (LCH)-associated neurodegenerative disease (ND)-like radiological findings. One patient showed typical radiological abnormalities at onset, which worsened with progressing central nervous system symptoms 7 years after LCH-oriented chemotherapy. Another showed spontaneous regression of clinical symptoms, with a transient radiological change 1 year after salvage chemotherapy for recurrence of JXG. These data regarding JXG-associated ND will facilitate future investigation of the disease, as well as development of therapeutic interventions.

[Central nervous system disorders secondary to histiocytoses: neurodegeneration with potential for improvement]

Histiocytoses, including Langerhans cell histiocytosis (LCH) and Erdheim-Chester disease (ECD), are inflammatory myeloid tumors in which monocyte lineage cells aggregate in various organs, causing tissue damage. Most of these tumors harbor oncogenic mutations in mitogen-activated protein kinase (MAPK) pathway genes, typified by BRAFV600E. Some patients with LCH develop bilateral symmetrical cerebellar lesions and brain atrophy several years after diagnosis when the initial symptoms disappear, leading to cerebellar ataxia and higher cerebral dysfunction. A similar neurological disorder has also been reported in ECD. This neurological disorder can be improved with MAPK inhibitors. When patients with this neurological disorder are identified among neurodegeneration of unknown etiology or histiocytosis patients and treated early with MAPK inhibitors, the disorder can be reversible.

Circulating senescent myeloid cells infiltrate the brain and cause neurodegeneration in histiocytic disorders

Neurodegenerative diseases (ND) are characterized by progressive loss of neuronal function. Mechanisms of ND pathogenesis are incompletely understood, hampering the development of effective therapies. Langerhans cell histiocytosis (LCH) is an inflammatory neoplastic disorder caused by hematopoietic progenitors expressing mitogen-activated protein kinase (MAPK)-activating mutations that differentiate into senescent myeloid cells that drive lesion formation. Some individuals with LCH subsequently develop progressive and incurable neurodegeneration (LCH-ND). Here, we showed that LCH-ND was caused by myeloid cells that were clonal with peripheral LCH cells. Circulating BRAFV600E+ myeloid cells caused the breakdown of the blood-brain barrier (BBB), enhancing migration into the brain parenchyma where they differentiated into senescent, inflammatory CD11a+ macrophages that accumulated in the brainstem and cerebellum. Blocking MAPK activity and senescence programs reduced peripheral inflammation, brain parenchymal infiltration, neuroinflammation, neuronal damage and improved neurological outcome in preclinical LCH-ND. MAPK activation and senescence programs in circulating myeloid cells represent targetable mechanisms of LCH-ND.

A case of neurodegenerative Langerhans cell histiocytosis exhibiting high osteopontin in cerebrospinal fluid without specific radiological abnormalities

Neurodegenerative Langerhans cell histiocytosis (ND-LCH) manifests several years after onset of LCH, with progressive neurological symptoms and characteristic brain imaging features. Although ND-LCH has a dismal neurological prognosis, distinct treatment strategies are not available owing to the unknown pathophysiology. We describe the case of a 6-year-old boy who developed left convergent strabismus four years after onset of multisystem LCH (MS-LCH). Although radiological imaging showed no abnormalities, the osteopontin level in the cerebrospinal fluid (CSF-OPN) was highly elevated without other abnormal CSF findings, leading to a diagnosis of ND-LCH. The patient received monthly intravenous immunoglobulin therapy for four years, without symptoms worsening. To investigate the relevance of OPN levels in LCH, we retrospectively analyzed serum and CSF OPN levels in eight LCH patients. Serum OPN levels were markedly elevated in the two MS-LCH patients with macrophage activation (400 and 445 ng/mL) compared to the other six patients (mean: 59 ng/mL). CSF-OPN levels were elevated in the ND-LCH patient (620 ng/mL) compared to the two patients with pituitary involvement (160 and 182 ng/mL), suggesting that the pathophysiology of ND-LCH reflects its inflammatory status. Analysis of CSF-OPN levels would be a useful tool to detect and treat ND-LCH.

[Therapeutic Strategies In Children And Adolescents With Langerhans Cell Histiocytosis]

The current standard therapy for children and adolescents with newly diagnosed Langerhans cell histiocytosis (LCH) is based on the two drugs prednisone and vinblastine. In patients with insufficient treatment response or disease relapse, the choice of second-line treatment depends on risk organ involvement (liver, spleen, and hematopoietic system). This article will give an overview of current data concerning therapeutic options in the different settings of children and adolescents with LCH. Due to limited evidence, these strategies have not been described in detail in the updated guidelines on pediatric LCH. In addition, the use of targeted therapy such as MAP-kinase inhibitors will be discussed. The reference center for LCH should be contacted if therapeutic options beyond the standard regimen are considered for treatment. All children and adolescents with LCH should be enrolled in registries or prospective studies.

Circulating senescent myeloid cells drive blood brain barrier breakdown and neurodegeneration

Neurodegenerative diseases (ND) are characterized by progressive loss of neuronal function. Mechanisms of ND pathogenesis are incompletely understood, hampering the development of effective therapies. Langerhans cell histiocytosis (LCH) is an inflammatory neoplastic disorder caused by hematopoietic progenitors expressing MAPK activating mutations that differentiate into senescent myeloid cells that drive lesion formation. Some patients with LCH subsequently develop progressive and incurable neurodegeneration (LCH-ND). Here, we show that LCH-ND is caused by myeloid cells that are clonal with peripheral LCH cells. We discovered that circulating BRAF V600E + myeloid cells cause the breakdown of the blood-brain barrier (BBB), enhancing migration into the brain parenchyma where they differentiate into senescent, inflammatory CD11a + macrophages that accumulate in the brainstem and cerebellum. Blocking MAPK activity and senescence programs reduced parenchymal infiltration, neuroinflammation, neuronal damage and improved neurological outcome in preclinical LCH-ND. MAPK activation and senescence programs in circulating myeloid cells represent novel and targetable mechanisms of ND.

Craniofacial involvement in Langerhans cell histiocytosis: A review of 44 cases at a single medical center

BACKGROUND

Craniofacial bones are the most commonly involved site of Langerhans cell histiocytosis (LCH). The main purpose of this study was to clarify the relation between subsites of craniofacial bone and clinical presentation, treatment modalities, outcomes, and permanent consequences (PCs) in patients with LCH.

METHODS

Forty-four patients diagnosed with LCH involving the craniofacial region presenting at a single medical center during 2001-2019 were collected and divided into four groups: single system with unifocal bone lesion (SS-LCH, UFB); single system with multifocal bone lesions (SS-LCH, MFB); multisystem without risk organ involvement (MS-LCH, RO-); and multisystem with risk organ involvement (MS-LCH, RO+). Data including demographics, clinical presentation, treatments, outcomes, and the development of PC were retrospectively reviewed.

RESULTS

Temporal bone (66.7% versus 7.7%, p = 0.001), occipital bone (44.4% versus 7.7%, p = 0.022), and sphenoid bone (33.3% versus 3.8%, p = 0.041) involvement were more common in SS-LCH, MFB than they were in SS-LCH, UFB. No difference of reactivation rate was noted among the four groups. The most common PC is diabetes insipidus (DI), reported in 9 of the 16 (56.25%) patients with PC. The single system group was reported with the lowest incidence of DI (7.7%, p = 0.035). The reactivation rate was also higher in patients with PC (33.3% versus 4.0%, p = 0.021) or DI (62.5% versus 3.1%, p < 0.001).

CONCLUSION

An increased risk of multifocal or multisystem lesions was associated with temporal bone, occipital bone, sphenoid bone, maxillary bone, eye, ear, and oral involvement, which may indicate poor outcomes. Longer follow-up may be indicated if there is the presence of PC or DI due to the high risk of reactivation. Therefore, multidisciplinary evaluation and treatment according to risk stratification are vital for patients diagnosed with LCH involving the craniofacial region.

Relapses of multisystem/multifocal bone Langerhans cell histiocytosis in paediatric patients: Data analysis from the JLSG-96/02 study

We assessed relapse patterns in paediatric patients with relapsed Langerhans cell histiocytosis (LCH) who were initially treated with the JLSG-96/02 protocol. We analysed 187 relapse events in 101 relapsed LCH patients [31 with multifocal bone (MFB) and 70 with multisystem (MS) at LCH diagnosis] among a total 317 patients enrolled in JLSG-96/-02 studies. Relapse of LCH was defined as an exacerbation of the non-active disease (NAD) condition. Of the 317 patients, 101 (31.9%) had the first relapse at 1.5 years after initiation of therapy. The first relapse and subsequent relapses did not differ between patients with MFB and MS disease. Of the 187 relapse events, relapse occurred as a single-system disease (n = 159; 85%), in which isolated bone relapse (n = 104; 55%) was the most common. Relapse at MS disease with the risk of organ involvement is extremely rare. After relapse(s), most patients underwent chemotherapy (122/187; 65%) and 87% of them achieved NAD status again. The incidence of permanent consequences was significantly higher in patients with relapses than in those without relapses. In the JLSG cohort, bone relapse most occurred in both MFB and MS patients. Most relapses could be effectively controlled by repeated administration of the initial chemotherapy.

Socio-behavioral dysfunction in disorders of hypothalamic-pituitary involvement: The potential role of disease-induced oxytocin and vasopressin signaling deficits

Disorders involving hypothalamic and pituitary (HPIT) structures-including craniopharyngioma, Langerhans cell histiocytosis, and intracranial germ cell tumors-can disrupt brain and endocrine function. An area of emerging clinical concern in patients with these disorders is the co-occurring socio-behavioral dysfunction that persists after standard hormone replacement therapy. Although the two neuropeptides most implicated in mammalian social functioning (oxytocin and arginine vasopressin) are of hypothalamic origin, little is known about how disease-induced damage to HPIT structures may disrupt neuropeptide signaling and, in turn, impact patients' socio-behavioral functioning. Here we provide a clinical primer on disorders of HPIT involvement and a review of neuropeptide signaling and socio-behavioral functioning in relevant animal models and patient populations. This collective evidence suggests that neuropeptide signaling disruptions contribute to socio-behavioral deficits experienced by patients with disorders of HPIT involvement. A better understanding of the biological underpinnings of patients' socio-behavioral symptoms is now needed to enable the development of the first targeted pharmacological strategies by which to manage patients' socio-behavioral dysfunction.

Clinical features and treatment of Langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH) is caused by the expansion of CD1a+/CD207+ cells and is characterised by a wide spectrum of organ involvement and dysfunction, affecting all ages. While almost all organs and systems can be affected, only the involvement and dysfunction of liver, spleen, and haematopoietic system influence survival. The LCH pathogenic cells are defined by universal activation of the mitogen-activated protein kinase (MAPK) signalling pathway. The most common alteration is a somatic BRAFV600E mutation, which is present in approximately two-thirds of the cases, followed by MAP2K1 mutations. Treatment of LCH is risk-adapted; patients with single lesions may respond well to local treatment, whereas patients with multi-system disease require systemic chemotherapy. While survival for patients without organ dysfunction is excellent, mortality rates for patients with organ dysfunction may reach 20%. Despite progress made in the treatment of LCH, disease reactivation rates remain above 30%, and standard second-line treatment has yet to be established. Long-term effects, including neuroendocrine dysfunction and neurodegeneration, represent a major challenge for survivors. Treatment with BRAF or MEK inhibitors results in immediate responses, but reactivations are very common after discontinuation. Their role as single agents and in combination with chemotherapy is being explored.

Histiocytosis and the nervous system: from diagnosis to targeted therapies

Histiocytoses are heterogeneous hematopoietic diseases characterized by the accumulation of CD68(+) cells with various admixed inflammatory infiltrates. The identification of the pivotal role of the mitogen-activated protein kinase (MAPK) pathway has opened new avenues of research and therapeutic approaches. We review the neurologic manifestations of 3 histiocytic disorders with frequent involvement of the brain and spine: Langerhans cell histiocytosis (LCH), Erdheim-Chester disease (ECD), and Rosai-Dorfman-Destombes disease (RDD). Central nervous system (CNS) manifestations occur in 10%-25% of LCH cases, with both tumorous or neurodegenerative forms. These subtypes differ by clinical and radiological presentation, pathogenesis, and prognosis. Tumorous or degenerative neurologic involvement occurs in 30%-40% of ECD patients and affects the hypothalamic-pituitary axis, meninges, and brain parenchyma. RDD lesions are typically tumorous with meningeal or parenchymal masses with strong contrast enhancement. Unlike LCH and ECD, neurodegenerative lesions or syndromes have not been described with RDD. Familiarity with principles of evaluation and treatment both shared among and distinct to each of these 3 diseases is critical for effective management. Refractory or disabling neurohistiocytic involvement should prompt the consideration for use of targeted kinase inhibitor therapies.

Long-term outcome, clinical course and treatment approaches of paediatric langerhans cell histiocytosis: A greek reference centre report

AIM

Langerhans cell histiocytosis (LCH) is an inflammatory myeloid neoplasia with diverse clinical behaviour. In this article, we studied the clinical course, management and long-term outcomes of a paediatric cohort treated by our reference centre.

METHODS

We retrospectively studied 66 children with LCH, consecutively diagnosed by a Greek reference centre from 1974 to 2020.

RESULTS

The patients had a median age of 3.9 (range 0.0-15.9) years, 39 and 6 patients were diagnosed with unifocal or multifocal single system disease and 14 and 7 had multisystem disease with or without risk organ involvement. No late occurrence of clinical neurodegenerative disease or diabetes insipidus were observed at a median follow-up period of 4.1 (range 0.5-27.7) years. The 10-year event-free survival and overall survival were 65.0% and 90.3% and improved significantly over a 45-year period. Survival was superior in single system than multisystem cases. BRAF V600E mutation was found in 8/14 tested patients. Reactivation occurred in 12/66 patients (18.2%); 11 achieved remission and one patient died after a second relapse.

CONCLUSION

LCH survival rates significantly increased in our cohort over time. Reactivation occurred in 18.2% patients, but no late neurodegeneration was found. The prognostic value of single system disease status vs. multisystem LCH was confirmed.

Neonatal Fc receptor induces intravenous immunoglobulin growth suppression in Langerhans cell histiocytosis

The neonatal Fc receptor (FcRn) plays a role in trafficking IgG and albumin and is thought to mediate intravenous immunoglobulin (IVIG) therapy for certain diseases. IVIG can be used for the treatment of human Langerhans cell histiocytosis (LCH); however, the mechanism remains unclear. The expression and function of FcRn protein have not been studied in LCH, though the expression of FcRn messenger RNA (mRNA) have been reported. In this report, we confirmed the expression of FcRn in 26 of 30 pathological cases (86.7%) diagnosed immunohistochemically as LCH. The expression was independent of age, gender, location, multi‐ or single‐system, and the status of BRAFV600E immunostaining. We also confirmed the expression of FcRn mRNA and protein in the human LCH‐like cell line, ELD‐1. FcRn suppressed albumin consumption and growth of IVIG preparation‐treated ELD‐1 cells, but not of IVIG preparation‐untreated or FcRn‐knockdown ELD‐1 cells. In addition, FITC‐conjugated albumin was taken into Rab11‐positive recycle vesicles in mock ELD‐1 cells but not in FcRn‐knockdown ELD‐1 cells. IVIG preparation prolonged this status in mock ELD‐1 cells. Therefore, ELD‐1 recycled albumin via FcRn and albumin was not used for metabolism. Our results increase our understanding of the molecular mechanism of IVIG treatment of LCH.

Long-term complications in uniformly treated paediatric Langerhans histiocytosis patients disclosed by 12 years of follow-up of the JLSG-96/02 studies

Langerhans cell histiocytosis (LCH) is a rare inflammatory myeloid neoplasia derived from immature myeloid dendritic cells with the mitogen-activated protein kinase (MAPK) pathway gene mutation. LCH is rarely fatal, but patients develop various permanent consequences (PCs). We report the frequencies of LCH-related PCs in paediatric patients (n = 317) treated by the JLSG-96/02 AraC-containing regimens. One-third of LCH patients had at least one PC at a median follow-up of 12 years. Central nervous system (CNS)-related PCs (neurological and endocrinological) accounted for 21·5%, non-CNS-related 16·7%. We require novel therapeutic measures to further reduce the frequency of LCH-related PCs.

Primary oral manifestation of Langerhans cell histiocytosis refractory to conventional therapy but susceptible to BRAF-specific treatment: a case report and review of the literature

Langerhans cell histiocytosis (LCH) is a diagnostic and therapeutic challenge. We report on a rare case of its primary oral manifestation that was treated successfully with the BRAF-specific agent, vemurafenib, after insufficient standard LCH treatment. This case underlines the importance of proper diagnosis and the evaluation of targeted therapy as a valuable tool in LCH treatment. Furthermore, the close collaboration of surgeons, oncologists, and dentists is mandatory to ensure adequate treatment, restore the stomatognathic system in debilitating post-treatment situations, improve quality of life, and ensure effective disease control in infants and young patients.

Central diabetes insipidus in pediatric patients with Langerhans cell histiocytosis: Results from the JLSG-96/02 studies

PURPOSE

We analyzed central diabetes insipidus (CDI) development in pediatric patients with Langerhans cell histiocytosis (LCH) treated according to the Japan LCH Study Group (JLSG) regimen, which is the combination chemotherapy including cytarabine (Ara-C).

METHODS

Retrospective data from 317 patients (multisystem disease (MS), n = 206; multiple focal bone (MFB), n = 111) treated according to the JLSG-96/02 regimens were analyzed.

RESULTS

The median follow-up duration was 10.6 years (range, 0.1-21.1). A total of 50/317 (15.8%) patients developed CDI (MFB, n = 4; MS, n = 46). Of the 50 cases, CDI was already present at the time of LCH diagnosis (pre-CDI) in 25, and it newly developed after the diagnosis and initiation of treatment (post-CDI) in the other 25 cases. The cumulative incidence of post-CDI at 10-year calculated by Kaplan-Meier analysis was 9.0% for total and 12.0% for MS patients. A positive correlation with LCH lesions at the CNS risk sites at diagnosis was found in pre-CDI cases (17/164 vs 8/171; P = 0.0359), but not in post-CDI cases (14/129 vs 11/163; P = 0.254). Multivariate analysis showed that relapse at the CNS risk sites was significantly associated with post-CDI development (hazard ratio: 4.70; 95% CI, 1.29-17.1, P < 0.05).

CONCLUSIONS

In the JLSG-96/02 studies, CDI developed in 15.8% of the cohort in which half as pre- and the other half as post-CDI. Relapse, particularly at the CNS risk sites, was linked with the development of post-CDI.

Rituximab therapy for patients with Langerhans cell histiocytosis-associated neurologic dysfunction

OBJECTIVE

Since patients with langerhans cell histiocytosis and neurologic dysfunction (LCH-ND) often have incomplete treatment responses we sought a new treatment regimen. Because of clinical benefit from rituximab in multiple sclerosis patients with neurodegeneration, we evaluated its use in patients with LCH-ND.

PARTICIPANTS

Eight LCH-ND patients who had failed prior therapies.

METHODS

Charts of the 8 patients treated with rituximab were reviewed. Signs/symptoms and MRI responses were assessed.

RESULTS

Seven of eight patients experienced some clinical improvement: gait abnormalities and tremors in four children, proprioceptive deficits in 2, and dysarthria/dysphagia in 2. Five of eight patients demonstrated improvement in intellectual/behavioral/psychological symptoms.

CONCLUSION

These findings suggest that prospective studies are warranted to define safety and efficacy of rituximab for patients with LCH-ND.

Langerhans cell histiocytosis in children - a disease with many faces. Recent advances in pathogenesis, diagnostic examinations and treatment

Langerhans cell histiocytosis is a rare clonal disease characterized by the proliferation of CD1a-positive immature dendritic cells. The purpose of this article was to present an updated review of recent advances in the pathogenesis, clinical features, imaging and treatment of this disease. The discovery of oncogenic BRAF mutations and the presence of proinflammatory cytokines and chemokines confirmed the unusual characteristics of this disease. Currently, children with organ involvement who do not have a good response to chemotherapy and have neurodegeneration or diabetes insipidus are the most problematic patients. Further research is needed to improve the results of treatment.

Evaluation and treatment of Langerhans cell histiocytosis patients with central nervous system abnormalities: Current views and new vistas

Central nervous system (CNS) involvement in Langerhans cell histiocytosis (LCH) can include mass lesions of the hypothalamic pituitary axis, choroid plexus, cerebrum, and cerebellum or magnetic resonance imaging (MRI) signal abnormalities of the cerebellum, pons, and basal ganglia. The term neurodegenerative (ND) CNS-LCH has been given to the MRI signal abnormalities and neurologic dysfunction, although initially patients may have no clinical symptoms. Standardized evaluations to better understand the natural history and response to therapy are needed. We propose guidelines for clinical, radiologic, and physiologic tests as a framework for developing the best methods of evaluation, which can then be tested in prospective treatment protocols.

Late outcomes in children with Langerhans cell histiocytosis

INTRODUCTION

Langerhans cell histiocytosis (LCH) is a rare disease with diverse clinical courses. Despite improvement in survival outcomes in the recent decades, sequelae of the disease remain a concern. This study aimed to provide information on the long-term outcomes in patients with LCH, particularly on the sequelae and any associated factors.

METHOD

Medical records of patients with diagnosis of LCH and being managed in our centre were retrospectively reviewed. Data on the courses of illness, mortality, intervention, types and time of late events were collected and analysed.

RESULTS

70 patients were included with a mean observation time of 12 years (median 10.7 years, range 1-31.3 years). Sequelae related to LCH were present in 56% (n=39), being more common in multisystem diseases and patients with reactivations. Prevalence of sequelae is as follows: orthopaedic related 27%, diabetes insipidus 19%, growth retardation 13%, cosmetic 10%, neurological 7%, hearing 7%, anterior pituitary hormone deficiency 7%, hepatobiliary 4% and ophthalmological 3%. Neurological sequelae could manifest even 10 years after initial diagnosis of LCH. Reactivations, presence of central nervous system (CNS) risk lesions and treatment with radiotherapy were associated with a higher rate of sequelae. The cumulative incidence of reactivation was 34%. Most reactivations occurred in the first 2.5 years after diagnosis.

CONCLUSION

Sequelae were common after LCH, although some were mild. Neurological sequelae could be particularly severe and debilitating. Vigilant long-term follow-up would be essential for optimising patient outcomes. Further studies on the prevention and treatment of CNS disease of LCH are warranted.

Histiocytoses: emerging neoplasia behind inflammation

Histiocytoses are disorders characterised by inflammation and the accumulation of cells derived from the monocyte and macrophage lineages, which results in tissue damage. Although they are often considered rare disorders with protean clinical manifestations, considerable advances in the understanding of their genetics have led to increased clinical recognition of these conditions, and fuelled further insights into their pathogenesis. In this Review, we describe insights into the cells of origin, molecular pathology, clinical features, and treatment strategies for some of the most common histiocytic disorders, including Langerhans cell histiocytosis, Erdheim-Chester disease, and Rosai-Dorfman disease. With the discovery of recurrent mutations affecting the mitogen-activated protein kinase and mTOR-AKT pathways in some of these histiocytoses, our understanding of these diseases has now evolved from the concept of a primary inflammatory condition to that of a clonal neoplastic disease. This understanding has led to the development of effective mechanism-based therapeutic strategies for patients with histiocytic diseases.

Usual and Unusual Manifestations of Familial Hemophagocytic Lymphohistiocytosis and Langerhans Cell Histiocytosis

Familial hemophagocytic lymphohistiocytosis (FHL) and Langerhans cell histiocytosis (LCH) are histiocytic diseases that occur most commonly in young children. Improvements in recognition and treatment have been substantial for both diseases in the past decade, although early and late morbidity continue to be major concerns. These two diagnoses behave differently, although the clinical spectra for both diseases are diverse and can lead to confusion and delays in diagnosis and treatment. This article focuses on the clinical and genetic spectrum of FHL as well as the clinical and treatment variations of LCH.

Pediatric Suprasellar Tumors

The various childhood suprasellar tumors, while pathologically distinct, present similar clinical and surgical challenges as a result of their common anatomic location. These lesions are in close proximity to or may invade the optic nerve and chiasm, pituitary gland and infundibulum, hypothalamus, and third ventricle, leading to presenting features including visual field loss, impairment in visual acuity, endocrine dysfunction, and hydrocephalus. Though many suprasellar lesions are relatively benign in pathology, treatment may be complicated by high surgical morbidity resulting from damage to the hypothalamic-pituitary axis. Here we review the most frequent pediatric lesions occurring in the suprasellar region: craniopharyngioma, chiasmatic glioma, germ cell tumor, Rathke cleft and arachnoid cysts, pituitary adenoma, and histiocytosis. This review outlines both common presenting features and differentiating aspects of these lesions. It also includes classic radiographic presentations and treatment considerations for each lesion.