Risk factors for diabetes insipidus in langerhans cell histiocytosis

Extracorporeal membrane oxygenation in the treatment of critical Pneumocystis jirovecii pneumonia in a child with Langerhans cell histiocytosis: a case report and literature review

BACKGROUND

Children with Langerhans cell histiocytosis (LCH) are particularly susceptible to infections such as Pneumocystis jirovecii pneumonia (PJP) due to the immunosuppressive effects of chemotherapy, which can progress to acute respiratory distress syndrome (ARDS) and respiratory failure. The use of Extracorporeal Membrane Oxygenation (ECMO) to manage hypoxemia secondary to PJP in LCH presents unique challenges, including the prevention of catheter-related bloodstream infections associated with arterial and venous access. This study explores a case wherein ECMO was crucial in treating severe PJP-induced respiratory failure in a pediatric patient with LCH.

CASE PRESENTATION

A 3-year-old female with a history of LCH, undergoing long-term chemotherapy and corticosteroid treatment, was admitted with fever, dyspnea, and lethargy. Metagenomic next-generation sequencing (mNGS) of bronchoalveolar lavage fluid confirmed Pneumocystis jirovecii (PJ). Despite aggressive management with invasive high-frequency ventilation, inhaled nitric oxide, and prone positioning, the patient's oxygenation remained critically low, with severe hypercapnia and resultant severe respiratory acidosis, necessitating vasopressor support for hemodynamic stability and venoarterial (VA) ECMO intervention. Early initiation of VA ECMO facilitated ultraprotective lung ventilation and circulatory support, effectively preventing hemodynamic collapse. The patient was successfully decannulated after 13 days of ECMO support.

CONCLUSION

While PJP is a rare and extremely serious opportunistic infection, the VA ECMO support in this pediatric case effectively managed severe PJP without ECMO-related complications. This highlights ECMO as a potentially viable, relatively effective, and safe adjunctive therapy in the management of severe PJP infections in children.

Clinical Characteristics and Treatment of Histiocytic Disorders in Children

Several distinct histiocytic neoplasms occur in children. These diseases are rare and their behavior is remarkably variable. In this article, the clinical and histopathologic features of Langerhans cell histiocytosis, Juvenile Xanthogranuloma, Rosai-Dorfman-Destombes, and ALK + Histiocytosis are reviewed. Recommendations for diagnostic evaluation of these entities are included and treatment approaches are presented.

Updates on Langerhans cell histiocytosis and other histiocytosis in children: invited review-challenges and novelties in paediatric tumours

Langerhans cell histiocytosis (LCH), juvenile xanthogranuloma (JXG) family lesions, and Rosai-Dorfman-Destombes disease (RDD) are now classified by the World Health Organization (WHO) under the heading of histiocytic/dendritic cell neoplasms. Each disease may manifest as a focal lesion, as multiple lesions, or as a widespread aggressive systemic disease with visceral organ involvement. Erdheim-Chester disease (ECD) is a rare systemic disease process of adults with limited cases in children. Challenges in diagnosis and novel disease presentations, including ALK-positive histiocytosis (a newly recognized WHO entity), mixed histiocytosis, and secondary histiocytic lesions following a prior leukemia/lymphoma are also discussed. Malignant histiocytic neoplasms (MHN) are distinct high-grade histiocytosis, which while rare in childhood occur both as primary disease and as secondarily after a prior hematologic malignancy. Of note, despite its name, hemophagocytic lymphohistiocytosis (HLH) is not considered a histiocytic neoplasm and does not define one specific disease "entity." HLH is a spectrum of hyperinflammation with various triggers and is not covered for the purposes of this targeted review.

Approach to the Patient: From Endocrinopathy to the Diagnosis of a Histiocytic Disorder

Endocrinopathies are frequently the initial presentation of histiocytic neoplasms, which are rare hematologic disorders affecting multiple organ systems. Langerhans cell histiocytosis and Erdheim-Chester disease are 2 such disorders known to infiltrate the hypothalamus and/or pituitary gland, leading to arginine vasopressin deficiency (AVP-D) and anterior pituitary dysfunction (APD) in 20% to 30% of cases, often as the first manifestation. Conversely, histiocytic disorders account for a notable proportion (10-15%) of all pituitary stalk lesions. The diagnosis of histiocytoses is often delayed in such cases due to the nonspecific presentation of endocrinopathies and pituitary involvement. Consequently, endocrinologists are at the frontline and uniquely positioned to achieve early diagnosis by recognizing the varied nonendocrine features of these disorders. This article provides an overview of the endocrine manifestations of histiocytic disorders and presents a simplified algorithm to guide the diagnostic workup in cases presenting with "idiopathic" AVP-D or APD. Such cases should be evaluated for histiocytic neoplasms with additional imaging studies and biopsies of suspected disease sites. If no disease site beyond the pituitary is identified, the risks and benefits of a pituitary stalk lesion biopsy must be carefully considered. While treatments of histiocytic neoplasms are highly efficacious, endocrinopathies are considered permanent and require long-term hormone replacement. It remains unclear whether early diagnosis and novel targeted therapies can reverse these endocrine disorders. Therefore, the role of the endocrinologist role is critical in the diagnosis and management of these rare diseases.

Pediatric Meningeal Diseases: What Radiologists Need to Know

Evaluating altered mental status and suspected meningeal disorders in children often begins with imaging, typically before a lumbar puncture. The challenge is that meningeal enhancement is a common finding across a range of pathologies, making diagnosis complex. This review proposes a categorization of meningeal diseases based on their predominant imaging characteristics. It includes a detailed description of the clinical and imaging features of various conditions that lead to leptomeningeal or pachymeningeal enhancement in children and adolescents. These conditions encompass infectious meningitis (viral, bacterial, tuberculous, algal, and fungal), autoimmune diseases (such as anti-MOG demyelination, neurosarcoidosis, Guillain-Barré syndrome, idiopathic hypertrophic pachymeningitis, and NMDA-related encephalitis), primary and secondary tumors (including diffuse glioneuronal tumor of childhood, primary CNS rhabdomyosarcoma, primary CNS tumoral metastasis, extracranial tumor metastasis, and lymphoma), tumor-like diseases (Langerhans cell histiocytosis and ALK-positive histiocytosis), vascular causes (such as pial angiomatosis, ANCA-related vasculitis, and Moyamoya disease), and other disorders like spontaneous intracranial hypotension and posterior reversible encephalopathy syndrome. Despite the nonspecific nature of imaging findings associated with meningeal lesions, narrowing down the differential diagnoses is crucial, as each condition requires a tailored and specific treatment approach.

Liver transplantation in a child with sclerosing cholangitis due to Langerhans cell histiocytosis: a case report

Background

Langerhans cell histiocytosis (LCH) is a systemic neoplasia with diverse clinical manifestations, predominantly affecting bone and skin. However, in children, LCH presenting primarily with cholestasis is rare.

Case summary

We present the case of a 22-month-old boy who was admitted to our hospital with a history of intermittent fever and abdominal distension for over 2 months, and jaundice for over 1 month. Prior to admission, the child had been managed with anti-infective and anti-inflammatory drugs and supportive care at multiple hospitals without significant improvement. He was then referred to our facility for further treatment. Upon admission, a series of laboratory tests, imaging studies, and pathological examinations were conducted, revealing the presence of diabetes insipidus, sclerosing cholangitis (SC), and liver cirrhosis. These findings led to a clinical diagnosis of LCH. Given the absence of definitive pathological evidence, his progression to decompensated liver cirrhosis and his pronounced growth retardation, the child was deemed a candidate for living donor liver transplantation. Following the liver transplant, pathological examination of the explanted liver tissue confirmed the clinical diagnosis of LCH. The child received postoperative chemotherapy, which resolved his systemic symptoms and normalized liver function. There was no evidence of LCH recurrence. The symptoms of diabetes insipidus were controlled with desmopressin acetate, however, the existing destructive lesions in the pituitary gland persisted.

Conclusion

Sclerosing cholangitis is a late and severe form of liver involvement in LCH that may be accompanied by lesions in other tissues or organs. Along with pathological evidence, a diagnosis should be made based on characteristic rashes, osteolytic lesions, and thickening of the pituitary stalk. In children with LCH complicated by SC for whom pathological diagnostic evidence cannot be obtained, liver transplantation may be considered once signs of decompensated liver cirrhosis appear, followed by systemic chemotherapy to control active disease. This strategy represents a therapeutic approach with the potential to achieve a better prognosis in children with LCH.

Langerhans cell histiocytosis of the orbit: pediatric case series

OBJECTIVE

To describe the clinical, imaging characteristics, and treatment of pediatric orbital Langerhans cell histiocytosis (LCH).

DESIGN

Retrospective case series.

PARTICIPANTS

Children with orbital LCH.

METHODS

Children with orbital LCH who presented to 4 different centres over the past 10 years. Demographic details, presenting features, imaging, histopathology, immunohistochemistry, and management outcomes were analyzed.

RESULTS

Sixteen patients were reviewed. The mean age of presentation was 6.56 ± 4.38 years (range, 1-18 years). Eyelid swelling was the most common presenting feature (13, 81%), followed by proptosis (1, 5%), eyebrow swelling (1,5%), and temple swelling (1, 5%). Imaging revealed superior orbital lesions with osteolytic defects of the orbital roof in 13 (72.2%) patients. Frontal and zygomatic bones were the most commonly affected. All the orbital lesions were extraconal. All patients in the study were diagnosed with LCH from orbital tissue biopsy. Three patients also demonstrated extra-orbital involvement. Two patients (12.5%) had intraoperative steroid injection with curettage, and 1 patient (6.25%) underwent curettage only. The remainder of the patients (n = 13, 81.25%) received systemic steroids and chemotherapy after undergoing biopsy. All patients had complete remission of disease without any signs of recurrence, except for 1 case of refractory LCH.

CONCLUSIONS

LCH is a rare disorder of the orbit and should be considered in the differential diagnosis for osteolytic lesions involving the superior orbit among the pediatric age group. Histopathologic confirmation is mandatory. Although optimal treatment remains controversial, complete removal of unifocal orbital LCH is recommended and may be achieved through excision and curettage.

Cutaneous Manifestations of Langerhans Cell Histiocytosis in Pediatric Age: A Case Report

Langerhans cell histiocytosis (LCH) is a rare histiocytic neoplastic disorder that mainly affects the skin and bones, with dermatological manifestations that can be easily confused with other dermatological conditions, such as seborrheic eczema, psoriasis, lesions of herpes simplex virus infection, fungal infection, lichen planus, and cutaneous lymphomas. This case report describes an eight-month-old infant who, at a child health appointment, presented with progressive erythematous papulovesicular lesions, initially treated with hygiene measures (skin hydration and hygiene) and mupirocin ointment, but which persisted and worsened, leading to a skin biopsy. The diagnosis of self-limiting congenital histiocytosis was confirmed, and the child was referred to the Portuguese Oncology Institute. The case highlights the importance of early recognition of LCH, the multidisciplinary approach, and the crucial role of the family doctor in the diagnosis and appropriate management of this rare condition.

Langerhans cell histiocytosis mimicking acute dacryocystitis

Langerhans cell histiocytosis (LCH) is a myeloid neoplasm characterized by clonal neoplastic proliferation of Langerhans-type dendritic cells associated with an inflammatory infiltrate predominantly composed of lymphocytes and eosinophils. In this article, we present an unusual case of LCH with significant swelling in the left lacrimal sac region in a 3-year-old child, clinically mimicking acute dacryocystitis. Microscopically, it showed intense inflammatory infiltrate and histiocytes with irregular nuclei. The tumor cells were positive for S-100 protein, CD1a, and CD207 (langerin). Molecular study was positive for the V600E/E2/D mutation (EXON 15). This case emphasizes the importance of careful clinical, radiographic, and microscopic evaluation, as some neoplasms may mimic common benign lesions.

A multidisciplinary non-invasive approach to monitor response to intravenous immunoglobulin treatment in neurodegenerative Langerhans cell histiocytosis: a real-world study

Aims

Early detection and treatment of neurodegenerative Langerhans cell histiocytosis (ND-LCH) have been suggested to prevent neurodegenerative progression. The aim of the study is to validate a standardized multidisciplinary diagnostic work-up to monitor the intravenous immunoglobulins (IVIG) treatment response and the natural course of the disease in untreated patients.

Methods

Patients with abnormal somatosensory evoked potentials (SEPs) received monthly 0.5 g/kg IVIG. The diagnostic protocol included structural 3T MRI, neurological examination, brainstem auditory evoked potentials (BAEPs) and SEPs.

Results

Twenty-two patients were followed for 5.2 years (median) from the first MRI evidence of ND-LCH. Eleven patients received IVIG for 1.7 years (median). At treatment start neurological examination was abnormal in 10 patients, of whom two had severe clinical impairment and four had abnormal BAEPs. At last follow-up, 1/11 remained stable and 7/11 improved, while worsening of neurological or neurophysiological findings, or both, occurred in 3/11. Risk factors for worsening were a severe clinical or MRI ND-LCH at treatment initiation and prolonged exposure to LCH. Of the 11 untreated patients, none improved and three worsened.

Conclusions

Using a standardized diagnostic protocol, we demonstrated that IVIG treatment can lead to clinical stabilization or improvement in all pauci-symptomatic patients with an MRI grading of less than 4.

Langerhans cell histiocytosis: NACHO update on progress, chaos, and opportunity on the path to rational cures

Langerhans cell histiocytosis (LCH) is a myeloid neoplastic disorder characterized by lesions with CD1a-positive/Langerin (CD207)-positive histiocytes and inflammatory infiltrate that can cause local tissue damage and systemic inflammation. Clinical presentations range from single lesions with minimal impact to life-threatening disseminated disease. Therapy for systemic LCH has been established through serial trials empirically testing different chemotherapy agents and durations of therapy. However, fewer than 50% of patients who have disseminated disease are cured with the current standard-of-care vinblastine/prednisone/(mercaptopurine), and treatment failure is associated with long-term morbidity, including the risk of LCH-associated neurodegeneration. Historically, the nature of LCH-whether a reactive condition versus a neoplastic/malignant condition-was uncertain. Over the past 15 years, seminal discoveries have broadly defined LCH pathogenesis; specifically, activating mitogen-activated protein kinase pathway mutations (most frequently, BRAFV600E) in myeloid precursors drive lesion formation. LCH therefore is a clonal neoplastic disorder, although secondary inflammatory features contribute to the disease. These paradigm-changing insights offer a promise of rational cures for patients based on individual mutations, clonal reservoirs, and extent of disease. However, the pace of clinical trial development behind lags the kinetics of translational discovery. In this review, the authors discuss the current understanding of LCH biology, clinical characteristics, therapeutic strategies, and opportunities to improve outcomes for every patient through coordinated agent prioritization and clinical trial efforts.

Comprehensive considerations for dermatologists: the application of FDG-PET in evaluating cutaneous lesions in pediatric Langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH) is a complex disorder characterized by the clonal proliferation of Langerhans cells, primarily affecting children and adolescents. This condition exhibits a wide spectrum of clinical presentations, necessitating a multidisciplinary approach for diagnosis, treatment, and follow-up. Cutaneous manifestations of LCH are significant, mimicking common dermatoses and posing diagnostic challenges. [18F]Fluorodeoxyglucose-Positron Emission Tomography (FDG-PET) has emerged as an important tool in the evaluation of pediatric LCH, offering insights into disease activity, extent, and therapeutic response. Moreover, FDG-PET provides a non-invasive means to distinguish between active LCH skin lesions and other dermatological conditions with similar clinical appearances, enhancing diagnostic accuracy and aiding in disease monitoring. This educational review summarizes the utility of nuclear imaging techniques, with a focus on PET scans, in the diagnosis and management of cutaneous pediatric LCH. A comprehensive literature search identified seven relevant articles, including retrospective studies and case reports. These studies highlight the efficacy of FDG-PET in localizing active LCH skin lesions, monitoring disease activity, and guiding treatment decisions. FDG-PET represents a valuable imaging modality for dermatologists, oncologists, and pediatricians managing pediatric LCH patients with cutaneous involvement. This non-invasive technique contributes to improved diagnostic accuracy and facilitates early intervention, ultimately enhancing patient care and outcomes.

Exploration of treatment in childhood Langerhans cell histiocytosis based on inflammatory and malignant symptoms: a pilot study

BACKGROUND

Multisystem childhood Langerhans cell histiocytosis (LCH) patients, especially those with risk organ (RO) involved, had not been satisfactorily treated under the international traditional schemes as high incidences of reactivation with late sequelae were largely reported. Over years, we have observed that LCH patients with varied clinical symptoms responded differently to different drugs, suggesting the current grouping strategies based only on the number of organs involved might be inadequate. LCH has been defined as an inflammatory myeloid tumor, thus this study has innovatively divided LCH pediatric patients into inflammatory or malignant symptoms group, and given different intensity treatment regimens to different groups.

AIM

This clinical study aimed to explore a more appropriate patient grouping system according to the LCH symptom presentations and examine the clinical outcomes of treatment strategies in different groups.

METHODS

According to the clinical manifestations, 37 cases of children were divided into Group A (only inflammatory symptoms) and Group B (malignant symptoms with or without inflammatory symptoms). Patients in Group A and B were initially treated with vindesine (VDS) and methylprednisolone (PSL), and VDS, PSL, pirarubicin (THP) and cyclophosphamide (CTX), respectively. Treatment responses were evaluated six weeks after the induction therapy in all patients, and the criteria were disease status and clinical scores of symptoms.

RESULTS

Pre- and post-treatment scores were 1.22 ± 0.547 and 0.00 ± 0.00 in Group A, and 14.79 ± 1.686 and 1.00 ± 1.563 in Group B, respectively. All patients had subsequentlly received maintenance therapy without progressive disease. The 4-year overall survival (OS) rate was 100% in both groups and the 4-year event-free survival (EFS) was 94.4% in Group A and 89.5% in Group B, respectively. There were no obvious adverse events (AE) in Group A, whereas the main AE in Group B were alopecia and non-lethal hematological toxicity.

CONCLUSION

Stratification according to patients' clinical symptoms, with low-intensity treatment for inflammatory symptoms (mild manifestations) and intensive treatment with multiple drugs for malignant symptoms (severe manifestations), is a positive exploration that simplifies stratification method, achieves good long-term remission of the disease, and obtains a higher survival rate and quality of life, which seemed to be more appropriate for LCH patients.

[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.

Cerebellar peduncle damage in Langerhans cell histiocytosis-associated neurodegenerative disease revealed by diffusion tensor imaging

PURPOSE

To confirm the hypothesis that brain white matter damage is involved in the pathogenesis and disease progression of Langerhans cell histiocytosis (LCH)-associated neurodegenerative disease (ND), we aimed to analyze pediatric patients with LCH using diffusion tensor imaging (DTI).

METHODS

We enrolled 33 patients with LCH and obtained 33 DTI datasets. Using DTI-based tractography, fractional anisotropy (FA), apparent diffusion coefficient (ADC), axial diffusivity (AD), and radial diffusivity (RD) were measured in the cerebral and cerebellar white matter tracts. The participants were divided into three groups-non-ND, ND without clinical symptoms (r-ND), and ND with clinical symptoms (c-ND)-according to their clinical status during the examination with DTI. We compared the DTI parameters in white matter tracts were compared among the three groups.

RESULTS

In the order of non-ND, r-ND, and c-ND groups, the FA in superior cerebellar peduncle (SCP) and middle cerebellar peduncle (MCP) significantly decreased, the ADC, AD, and RD of MCP, and the RD of SCP were significantly elevated (FA-SCP; p < 0.001, FA-MCP; p = 0.026, ADC-MCP; p < 0.001, AD-MCP; p = 0.002, RD-MCP; p = 0.003, and RD-SCP; p = 0.018). Furthermore, in the simple linear regression analysis, the FA, ADC, AD, and RD values in the MCP and the FA value in the SCP were significantly influenced by the presence of neurological symptoms and ND findings on MRI (all p < 0.001).

CONCLUSION

In LCH-ND, we identified microstructural damage in the SCP and MCP. DTI parameters in these tracts may help monitor LCH-ND; therefore, future studies are required to validate these results in a large cohort.

Orbital histiocytosis and fibrohistiocytosis: the clinicopathological characteristics of 117 patients, over a decade of experience

PURPOSE

To describe the clinicopathological features of a large cohort of patients with orbital histiocytoses and fibrohistiocytosis, such as Langerhans cell histiocytosis (LCH) and non-LCH disorders, and correlate patients' clinical characteristics with their pathological diagnosis.

METHODS

In this retrospective study, medical records of patients presenting to Farabi Eye Hospital, a tertiary eye care center in Tehran, Iran, from 2010 until 2022, were reviewed. Patients' demographics, chief complaint, location and laterality of the tumor, best-corrected visual acuity, presence of bone erosion on imaging, and their pathological diagnosis were retrieved. Excisional biopsy was performed and evaluated through light microscopy and immunohistochemistry study for their respective markers, including CD1a, CD68, CD207, and S100.

RESULTS

A total of 117 patients with 11 pathological subtypes of histiocytoses and fibrohistiocyosis were identified, with 56.4% male and 43.6% female patients. The mean age at presentation was 23.4 years (range 1.5 months-73 years). Swelling and palpable mass were the most common chief complaints. LCH was the most common pathology (32.5%), followed by juvenile xanthogranuloma (26.5%) and adult xanthogranuloma (21.4%). Age, lesion location, and bone erosion had a statistically significant difference among the various diagnosed subtypes.

CONCLUSIONS

Histiocytoses and fibrohistiocytosis are diverse and rare disorders potentially involving multiple organ systems. Ophthalmic manifestations of these diseases are even more uncommon. We reviewed their orbital presentation along with their respective histopathological findings. Our results also suggested that an orbital CT scan can be of diagnostic value to discriminate LCH from other histiocytic pathologies.

[Updated AWMF Guideline on the Diagnosis and Treatment of Langerhans cell Histiocytosis in Children and Adolescents]

Langerhans cell Histiocytosis is a rare neoplastic disease, which occurs mainly in children and adolescents. The disease may affect any organ, and therefore, the clinical symptoms vary widely. Some patients have a spontaneous remission of the disease, whereas others experience a rapid and potentially lethal clinical course. The therapeutic approach depends on the extent of the disease, and reaches from a watch-and-wait strategy to chemotherapy with the standard drugs vinblastine and prednisone. The identification of mutations in the MAPK-pathway resulted in growing interest in targeted therapy using compounds such as the BRAF inhibitors. Chronic relapses and permanent sequelae are important problems of LCH and are the focus of current research.

[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.

A retrospective study comprising 228 cases of pediatric scalp and skull lesions

BACKGROUND

Most neurosurgery presentations in children present with a mass that may be scalp and skull lesions, including neoplastic and congenital malformed structural lesions, respectively. Clinicians should make early diagnoses and identify cases requiring surgical intervention promptly to help achieve a better prognosis.

METHOD

This study retrospectively reviewed studies on children's scalp and skull lesions within a pediatric medical center's department of neurosurgery. The detailed clinical information and pathological types of these cases were scrutinized.

RESULT

A total of 228 children's scalp and skull lesions with clinical information and identified histopathology types were summarized. The most common scalp and skull lesions were benign dermoid cysts; malignant types were rare but can occur in children.

CONCLUSION

Based on the combined clinical symptoms and image information, children's scalp and skull lesions should be diagnosed early. Malignant scalp and skull lesions/other special cases should be treated seriously.

Clinical and prognostic features of Langerhans cell histiocytosis in adults

Langerhans cell histiocytosis (LCH) is a rare disease characterized by clonal expansion of CD1a+ CD207+ myeloid dendritic cells. The features of LCH are mainly described in children and remain poorly defined in adults; therefore, we conducted a nationwide survey to collect clinical data from 148 adult patients with LCH. The median age at diagnosis was 46.5 (range: 20-87) years with male predominance (60.8%). Among the 86 patients with detailed treatment information, 40 (46.5%) had single system LCH, whereas 46 (53.5%) had multisystem LCH. Moreover, 19 patients (22.1%) had an additional malignancy. BRAF V600E in plasma cell-free DNA was associated with a low overall survival (OS) rate and the risk of the pituitary gland and central nervous system involvement. At a median follow-up of 55 months from diagnosis, six patients (7.0%) had died, and the four patients with LCH-related death did not respond to initial chemotherapy. The OS probability at 5 years post-diagnosis was 90.6% (95% confidence interval: 79.8-95.8). Multivariate analysis showed that patients aged ≥60 years at diagnosis had a relatively poor prognosis. The probability of event-free survival at 5 years was 52.1% (95% confidence interval: 36.6-65.5), with 57 patients requiring chemotherapy. In this study, we first revealed the high rate of relapse after chemotherapy and mortality of poor responders in adults as well as children. Therefore, prospective therapeutic studies of adults with LCH using targeted therapies are needed to improve outcomes in adults with LCH.

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.

Orbital Langerhans Cell Histiocytosis: A Case Report

An eight-year-old boy presented with a one-month history of left eyelid swelling. The patient was diagnosed with periorbital cellulitis at another clinic and was treated with oral antibiotics. However, the swelling did not subside. On initial consultation, the patient had left upper eyelid swelling with erythema. His extraocular muscle motility was normal, and the results of blood tests were unremarkable. A computed tomographic scan demonstrated a mass in the superior orbit with destructive changes in the left frontal bone. Histopathological examinations revealed a dense infiltrate of histiocytic cells. Immunohistochemical staining of the tumors for CD1a and Langerin was positive. A pathological diagnosis of Langerhans cell histiocytosis was made. Since orbital Langerhans cell histiocytosis has a high risk for central nervous system involvement, chemotherapy was the treatment of choice for any residual lesion to prevent sequelae to the central nervous system. At the six-month follow-up, the lesion did not recur, and the patient did not experience any central nervous system sequela.

Langerhans Cell Histiocytosis of the Head and Neck: Experience at a Rural Tertiary Referral Center

OBJECTIVES

Retrospectively analyze head and neck Langerhans Cell Histiocytosis at a rural tertiary referral center and compare results with previously published data.

METHODS

Electronic health record review was performed from 2003 to 2019. Patients with biopsy proven LCH with primary head and neck involvement were included. Demographics, presentation, imaging characteristics, treatment modality, delay in diagnosis (DD, ≥60 days), and outcomes were analyzed and reported.

RESULTS

Twenty-four patients were included. The most common presenting symptoms were otorrhea (n = 6) and scalp pain or swelling (n = 6). All patients had bony involvement. The most common site was facial or skull lesions (n = 20). Most skull lesions (75%) demonstrated CNS risk. Six patients were treated with primary surgery, 15 with primary chemotherapy, and 3 with surgery plus adjuvant chemotherapy. Nine patients experienced relapse of disease with median time to documented relapse of 11.4 months; all were treated with salvage chemotherapy to achieve complete remission (median follow-up: 72 months). Patients most likely to relapse were those with multisystem disease (5/7, 71.4%), temporal bone lesions (4/7, 57.1%), and DD (7/12, 58.3%). Of the 9 total patients who experienced relapse, 78% had a delay in diagnosis.

CONCLUSIONS

LCH is a complex disease process in which diagnosis can be delayed if not considered in the differential. Within the head and neck, the skull, including isolated temporal bone involvement, is the most common site of involvement. Treatment modality does not appear to have an influence on relapse rates. Relapse was more likely to occur in the first year after treatment and close monitoring is required.

Langerhans Cell Histiocytosis in Children: Literature Review

Relevant information on Langerhans cell histiocytosis development and course in children is presented. The current concepts of disease pathogenesis, principles of its severity evaluation, patients stratification into risk groups, as well as of clinical course features are described. Modern approaches to the disease treatment via targeted therapy are summarized and analyzed. 

Multifocal Multisystem Langerhans Cell Histiocytosis Involving Pituitary Masquerading as Crohn’s Disease: A Case Report and Review of the Literature

Background/Objective. We present a case of Langerhans cell histiocytosis (LCH) with gastrointestinal involvement masquerading as inflammatory bowel disease (IBD) in a patient who initially had features of central diabetes insipidus (CDI). Case Report. A 19-year-old male presented at 14 years of age with central diabetes insipidus. He subsequently developed panhypopituitarism and sellar-suprasellar mass, the biopsy of which was inconclusive. Secondary causes for hypophysitis were ruled out. Five years later, he developed perianal pus discharging sinuses, positive ASCA, and sacroiliitis. Rectal ulcer biopsy showed nonspecific inflammation and necrosis. Hence, he was managed as inflammatory bowel disease (IBD). Due to nonresponsiveness of symptoms, doubt about diagnosis was invoked and rectal ulcer biopsy was repeated, which then showed infiltration by Langerhans cells. Hence, he was diagnosed with LCH and showed resolution of symptoms on initiating steroids and vinblastine. Discussion. Gastrointestinal involvement by LCH is unusual and only rarely has represented a prominent clinical manifestation. In most cases, such involvement suggests widespread multisystem disease. Its distinctive morphologic and immunohistochemical features allow LCH to be distinguished from other inflammatory infiltrations found in mucosal biopsy specimens. Conclusion. Preceding CDI and hypopituitarism may predict LCH in patients with IBD-like diseases.

A Review of Noninfectious Diseases Masquerading as Acute Mastoiditis

OBJECTIVE

Acute mastoiditis is commonly attributed to infection. Rarely do clinicians encounter cases that do not respond to traditional antibiotics or surgical management. The goal of this study was to systematically review the literature to characterize diseases masquerading as acute infectious mastoiditis.

DATA SOURCES

PubMed, Embase, and Scopus.

REVIEW METHODS

A systematic review was performed to identify all publications that reported on diseases with presentations mimicking acute mastoiditis, defined as postauricular redness, swelling, and tenderness. We included clinical prospective studies, retrospective studies, and case series/reports. Exclusion criteria included non-English articles, letters/commentaries, abstracts, and review articles.

RESULTS

Out of 3339 results, 35 studies met final inclusion criteria. In children, 11 diseases were reported to mimic mastoiditis, including solid tumors, hematologic diseases, and autoimmune/inflammatory diseases. The most common disease in children was Langerhans cell histiocytosis, followed by rhabdomyosarcoma and acute myelogenous leukemia. In adults, 8 additional diseases were reported. The most common disease in adults was squamous cell carcinoma, followed by nasopharyngeal carcinoma and Langerhans cell histiocytosis. Presenting symptoms are reviewed, as well as characteristic radiographic, laboratory, and intraoperative features that may assist with diagnosis. A diagnostic algorithm for atypical cases of acute mastoiditis is proposed.

CONCLUSION

A small but significant group of diseases in children and adults can mimic acute mastoiditis. In such cases, history and examination alone may be insufficient to reach a diagnosis, and further investigation may be necessary. Otolaryngologists should always be mindful of the possibility that noninfectious pathologies may present with a constellation of symptoms similar to mastoiditis.

Histiocytic Disorders of Childhood

Histiocytic disorders of childhood represent a wide spectrum of conditions that share the common histologic feature of activated or transformed "histiocytes." Langerhans cell histiocytosis (LCH) is the most common, with an incidence of approximately 5 per million children. LCH may be difficult to distinguish from more ubiquitous causes of skin rashes, bone pain, or fever. Current chemotherapy fails to cure more than 50% of children with multifocal disease, and treatment failure is associated with increased risks of long-term sequelae. Somatic activating mitogen-activated protein kinase (MAPK) pathway-activating mutations (most often BRAFV600E) have been identified in hematopoietic precursors in patients with LCH. Opportunities to improve outcomes with targeted therapies are under investigation. Juvenile xanthogranuloma (JXG) and Rosai-Dorfman disease (RDD) are less common than LCH and are distinguished by specific histologic and clinical features. Recurrent MAPK pathway gene mutations are also identified in JXG and RDD. In many cases, these conditions spontaneously resolve, but disseminated disease can be fatal. Although there has been historic debate regarding the nature of these conditions as inflammatory versus neoplastic, LCH, JXG, and RDD are now considered myeloid neoplastic disorders. In contrast, hemophagocytic lymphohistiocytosis (HLH) is clearly a disorder of immune dysregulation. HLH is characterized by extreme immune activation driven by hyperactivated T cells. HLH arises in approximately 1 child per million and is nearly universally fatal without prompt recognition and immune suppression. Outcomes of treated children are poor, with approximately 60% survival. Emapalumab, which targets interferon-γ signaling, was recently approved for patients with recurrent or refractory HLH, and additional cytokine-directed therapies are under investigation.

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.

Treatment and Outcomes of Unifocal and Multifocal Osseous Pelvic Langerhans Cell Histiocytosis Lesions in a Pediatric Population

Introduction

Langerhans cell histiocytosis (LCH) is a rare, clonal disorder characterized by proliferation and tissue infiltration by myeloid dendritic cells, most commonly occurring in pediatric populations. It often manifests as skeletal lesions with possible pelvic involvement. Few studies have characterized and reviewed outcomes after treatment of isolated pelvic LCH lesions.

Methods

A retrospective single-institution review was conducted on diagnoses of patients younger than 18 with a diagnosis of unifocal or multifocal skeletal LCH lesions involving the pelvis. Clinical presentations, lesion sites, focal classification, radiographic findings, treatments, complications, and recurrence rates were reviewed.

Results

Twenty patients had unifocal or multifocal LCH pelvic lesions (11 males, nine females). The median age at diagnosis was 3.5 years (0.8-21.6). Eight cases (40%) involved unifocal lesions, and twelve (60%) involved multifocal lesions, with the most common associated skeletal disease occurring at the ilium. 100% of cases had a lytic bone lesion with no pathologic fractures. All cases were treated nonoperatively with chemotherapy medications, corticosteroids, or observation alone. 75% of cases were treated with chemotherapy with a 100% resolution rate. The median length of follow-up was 4.5 years (0.4-16.7). 

Conclusion

Our study found that chemotherapy alone or chemotherapy with corticosteroid supplementation are appropriate options for unifocal pelvic LCH lesions. In contrast, pelvic lesions that are part of a multifocal presentation may be managed adequately with varied chemotherapy regimens. Corticosteroid therapy and observation alone may also be reasonable for a single organ system, multifocal, skeletal lesions that are anatomically accessible for biopsy and small in number or size.

Langerhans cell histiocytosis in adolescent patients: a single-centre retrospective study

Background

Langerhans cell histiocytosis (LCH) is a myeloid dendritic cell disorder frequently affecting children more than adults. The presentation of LCH varies with age, however, the clinical characteristics and genetic profiles of adolescent LCH remain elusive. To address the knowledge gap, we performed a single-centre retrospective study of 36 adolescent LCH patients aged between 14 and 17 years at Peking Union Medical College Hospital.

Results

At the time of diagnosis, 10 patients were classified as unifocal single system LCH (27.8%), 2 patients had pulmonary single system LCH (5.6%), 5 patients had multifocal single system LCH with bone involvement (13.9%), and 19 patients had multisystem LCH (52.8%). The most prevalent involvement in multisystem patients was the pituitary gland (78.9%), followed by the bone (42.1%), lung (42.1%), and lymph nodes (42.1%). Eight (42.1%) patients had risk organ involvement. BRAF^N486_P490 was detected in 50% of patients who underwent next generation sequencing, and BRAF^V600E was detected in one patient. Chemotherapies were the first line treatment in 24 patients. One patient died and thirteen patients relapsed during the follow-up. The estimated 5-year OS rate and EFS rate were 94.7% and 59.0%, respectively.

Conclusions

In this study, we report a large series of adolescent LCH patients. The clinical characteristics of adolescent LCH patients may be close to adult LCH. Compared with pediatric cases, adolescent LCH tends to have more pituitary lesions and pulmonary involvement, fewer skin and hematopoietic involvement, a higher frequency of BRAF deletion mutation, and a lower frequency of BRAF^V600E mutation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-022-02436-0.

[A female patient with earache, polyuria and polydipsia]

INTRODUCTION

 Langerhans cell histiocytosis is a rare inflammatory bone marrow neoplasia that frequently affects bone, lung, skin and pituitary gland. Due to its broad spectrum of clinical presentation, an appropriate diagnosis might be difficult.

HISTORY

 A 54-year-old female patient complained of pain in her right ear for 5 months. On account of similar complaints, a mastoidectomy had already been performed 3 years ago. Histology at that time revealed nonspecific inflammation. Furthermore, she reported excessive thirst.

FINDINGS AND DIAGNOSIS

 Computed tomography of the temporal bones showed osteolysis in the mastoid. Magnetic resonance imaging and bone scintigraphy assessed these changes as uncharacteristically inflammatory. Polydipsia proved to be a symptom of central diabetes insipidus in the water deprivation test. Finally, remastoidectomy provided histologic evidence of Langerhans cell histiocytosis.

THERAPY AND COURSE

 Besides systemic chemotherapy with cytarabine, the patient also received denosumab and desmopressin.

CONCLUSION

 Langerhans cell histiocytosis involving cranial bones is often associated with diabetes Insipidus. Knowledge about the distinctive constellation may lead to a more rapid diagnosis and improved prognosis.

Approach to the Patient: Management of Pituitary Hormone Replacement Through Transition

Hypopituitarism in childhood is a rare, complex disorder that can present with highly variable phenotypes, which may continue into adult life. Pituitary deficits can evolve over time, with unpredictable patterns resulting in significant morbidity and mortality. Hypopituitarism and hypothalamic dysfunction may be associated with challenging comorbidities such as obesity, learning difficulties, behavioral issues, sleep disturbance, and visual impairment. Transition is the purposeful planned movement of adolescents and young adults with chronic conditions from child-centered to adult-oriented health care systems with a shift from parent- to patient-focused care. To achieve effective transition within a health care setting, the inherent challenges involved in the evolution from a dependent child to an independent adult must be recognized. Transition is a critical time medically for patients with hypopituitarism. Complex issues with respect to puberty, attainment of optimal stature, adherence to treatment, and acceptance of the need for life-sustaining medications need to be addressed. For health care professionals, transition is an opportunity for reassessment of the pituitary deficits and the need for lifelong replacement therapies, often against a background of complex psychological issues. We present 4 illustrative cases of hypopituitarism of differing etiologies with diverse clinical presentations. Diagnostic and management processes from clinical presentation to young adulthood are discussed, with a particular focus on needs and outcomes through transition.

Infantile-Onset Isolated Neurohypophyseal Langerhans Cell Histiocytosis with Central Diabetes Insipidus: A Case Report

Central diabetes insipidus (CDI) is a rare disease in children and has a variety of etiologies. The major causes of CDI with pituitary stalk thickening (PST) are germinoma, Langerhans cell histiocytosis (LCH), and Lymphocytic infundibulo-neurohypophysitis, which are difficult to differentiate by imaging and require pathological diagnosis. We report a case of infantile-onset isolated neurohypophyseal LCH diagnosed by pathological findings. A 2-year-old girl presented with polydipsia and polyuria. CDI was diagnosed and treatment with oral desmopressin was initiated. Magnetic resonance imaging (MRI) of the head showed PST and absence of high-signal intensity of posterior pituitary on T1-weighted images. Follow-up MRI scans showed that the tumor mass was gradually increasing and extending posteriorly toward the area near the mamillary body. Simultaneously, anterior pituitary dysfunction was observed. She underwent a biopsy of the PST and LCH was diagnosed by immunohistochemical analysis. DNA analysis showed no BRAF V600E mutation. Monotherapy with 2-Chlorodeoxyadenosine reduced the tumor size but did not improve pituitary function. Isolated neurohypophyseal LCH should be considered in infantile-onset cases of CDI with PST. 2-CdA treatment resulted in rapid PST shrinkage. Further cases are needed to determine whether early diagnosis and treatment can prevent anterior pituitary dysfunction.

A Case Report of Radiotherapy for Skull Lesions of Langerhans Cell Histiocytosis With Dural Invasion

Background

Langerhans cell histiocytosis (LCH) is a rare disease, especially in adults. It is often associated with non-fatal bone and skin lesions and has relatively good radiosensitivity. In contrast, brain and lymph node metastases from LCH lesions are considered to be less sensitive to radiotherapy.

Case Report

At our institution, 30 Gy radiotherapy was used to treat bone lesions with dural invasion in a patient with adult-onset LCH. The patient was treated with chemotherapy and radiotherapy for 21 years since the initial diagnosis. After radiotherapy, the tumor shrank rapidly, and a complete response was achieved 1 year after treatment. The patient survived without local recurrence.

Conclusion

Here, we report the details of this case, along with a review of the literature. We suggest that even with invasion of the tissues around the bone lesions in LCH, local recurrence can be prevented by middle radiation doses.

Langerhans cell histiocytosis presenting as an isolated brain tumour: A case report

BACKGROUND

Langerhans cell histiocytosis (LCH) is a rare proliferative histiocyte disorder. It can affect any organ or system, especially the bone, skin, lung, and central nervous system (CNS). In the CNS, the hypothalamic-pituitary is predominantly affected, whereas the brain parenchyma is rarely affected. LCH occurring in the brain parenchyma can be easily confused with glioblastoma or brain metastases. Thus, multimodal imaging is useful for the differential diagnosis of these intracerebral lesions and detection of lesions in the other organs.

CASE SUMMARY

A 47-year-old man presented with a headache for one week and sudden syncope. Brain computed tomography (CT) and magnetic resonance imaging showed an irregularly shaped nodule with heterogeneous enhancement. On ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/CT, a nodule with ¹⁸F-FDG uptake and multiple cysts in the upper lobes of both lungs were noted, which was also confirmed by high-resolution CT. Thus, the patient underwent surgical resection of the brain lesion for further examination. Postoperative pathology confirmed LCH. The patient received chemotherapy after surgery. No recurrence was observed in the brain at the 12-mo follow-up.

CONCLUSION

Multimodal imaging is useful for evaluating the systemic condition of LCH, developing treatment plans, and designing post-treatment strategies.

Second-line regimen for CNS-involved pediatric Langerhans cell histiocytosis

PURPOSE

Langerhans cell histiocytosis (LCH) can affect any organ. Central nervous system (CNS) involvement is rare, and its management is poorly understood. This study aimed to analyze the clinical response and prognosis of pediatric LCH with central diabetes insipidus (CDI) treated with second-line therapy with cytarabine (Ara-c), cladribine (2-cdA), dexamethasone, and vindesine.

METHODS

This retrospective case series study included pediatric LCH with CDI treated at Beijing Children's Hospital affiliated with Capital Medical University (11/2012-01/2018). After the first-line 2009-LCH regimen, patients with active disease/worse response, relapse, or no significant improvement in risk organs, pituitary, or lung were given the second-line therapy. Baseline characteristics, clinical response and adverse reactions were observed.

RESULTS

Twenty-six children with CDI and disappearance of hyperintensity in the posterior pituitary were included. They received "Regimen A" Ara-c + dexamethasone + vindesine (n = 7) or "Regimen B" Ara-c + dexamethasone + vindesine + 2-cdA (n = 19) as second-line therapy. There were 14 patients with CDI but without pituitary stalk thickening (PST) and 12 with CDI and PST. In patients with CDI alone, 4/4 patients receiving Regimen A and 3/10 receiving Regimen B improved. All patients with CDI and PST showed improvement for PST. The reappearance of hyperintensity at the posterior pituitary was observed in 10 patients with CDI. All 26 children were alive after a median follow-up of 40.5 months. There were no chemotherapy-related deaths.

CONCLUSION

A combined therapy with Ara-c, 2-cdA, dexamethasone, and vindesine could partially alleviate pituitary disease conditions in pediatric LCH with CNS involvement, with good tolerance.

Case report: "Congenital cutaneous langerhans cell histiocytosis presenting with blueberry Muffin Rash"

Congenital cutaneous Langerhans cell histiocytosis-(LCH), named Hashimoto Pritzker disease, is a rare subtype among the clinical spectrum of LCH that often presents at birth or through the neonatal term and spontaneously resolve within a few months. In rare instances, infants with congenital cutaneous LCH may present with a blueberry-muffin rash. We reported a case of a male newborn who presented with blueberry muffin rash and was diagnosed with congenital cutaneous LCH later on. The diagnosis was confirmed by excluding other possible systemic causes of blueberry muffin rash, followed by a skin biopsy. Skin biopsy showed reticular dermis-hypodermis infiltration by medium-sized cells which had a pale eosinophilic cytoplasm and irregular nuclei. The lesional cells were positive for Langerin, CD1a, S100, and CD68 immunostains, consistent with congenital cutaneous LCH. Investigations were performed and revealed no systematic disease involvement. After a discussion with the pediatric Hemato-Oncologist, the decision was to keep track of a "wait-and-see" approach. Long-term follow-up revealed no recurrence of the cutaneous lesions or any systemic involvement, which further leads to congenital cutaneous LCH diagnosis. Even though it is very rare, blueberry muffin rash differential diagnosis should include congenital cutaneous LCH. Early recognition of this condition protects patients from unnecessary and possibly unsafe systemic treatment.

Head and Neck Langerhans Cell Histiocytosis in Children

PURPOSE

Controversy exists among head and neck surgical specialties regarding management of Langerhan's Cell Histiocytosis (LCH). The purpose of this study was to evaluate diagnosis, management, and treatment outcomes in children with LCH of the head and neck.

METHODS

This is a retrospective cohort study of children with LCH of the head and neck who presented to Children's Healthcare of Atlanta hospital from 2009 to 2021. The independent variables were demographic information, lesion locations, clinical presentation, radiographic findings, diagnostic workup, treatment, and length of follow-up. The patients were grouped based on these variables. The outcome variable was disease reactivation. Descriptive statistics were calculated.

RESULTS

There were 3 presentations of LCH of the head and neck. Group 1 presented as a lesion in 1 system without CNS risk (SS-). There were 24 patients with an average age of 10 years. Lesions were located in calvaria and/or mandible. Majority of the patients were treated with only debridement. Two of the patients experienced reactivation. Group 2 presented as a lesion in 1 system with CNS risk (SS+). There were 30 patients with an average age of 6 years. Common locations were temporal bone and/or orbit. These patients present with recurrent ear infections and ptosis. Majority of the patients were treated with chemotherapy (n = 28). One patient had disease reactivation. Group 3 presented with multisystem involvement. There were 13 patients with an average age of 2 years. LCH was found in skin and the lymphatic system. Imaging demonstrated extracranial organ involvement. All of them were treated with chemotherapy. There was 40% reactivation of LCH.

CONCLUSIONS

Treatment of LCH depends on presentation. SS- subgroup can be adequately treated via surgical debridement. SS+ and multisystem groups benefit from an early disease diagnosis and require chemotherapy.

Langerhans cell histiocytosis in adults: a retrospective, single-center case series

Langerhans cell histiocytosis is rare in adults, and most of what we know about its diagnosis and treatment comes from pediatric studies. We report clinical findings and results of treatment in a retrospective series of 63 consecutive adult patients (18-76 years old), treated at our pediatric unit from 1990 to 2020 using the same approach as for children. Patients were classified as having single-system disease (SS-LCH) in 41 cases, which was unifocal in 34 of them and multifocal in 7, or multisystem disease (MS-LCH) in 17 and primary pulmonary (pLCH) in 5. Twenty patients also had diabetes insipidus. A "wait and see" strategy was recommended after biopsy/surgery for patients with unifocal SS-LCH. Systemic treatment was proposed for cases of SS-LCH involving "special sites" or with multifocal disease, and in cases of MS-LCH. EFS and OS for the cohort as a whole were 62.2% and 100%, respectively, at 5 years and 52.5% and 97.6% at 10 years. Three patients died due to the damage caused by the multiple therapies administered. The rate of disease reactivation was high (affecting 40% of cases), with several reactivations over the years despite multiple lines of treatment. Though clinical history of LCH may differ between adults and children, in the absence of specific, tailored protocols, clinical approach to adult cases may draw on pediatric experience. Patients with limited disease have a good prognosis without any need for systemic therapy. Potentially greater toxicity in adults of systemic treatments generally used in pediatric setting should be borne in mind.

A review of systemic infiltrative diseases and associated endocrine diseases

Systemic infiltrative diseases are relatively rare conditions consisting of cell infiltration or substance deposition in multiple organs and systems, including endocrine glands. This article reviews endocrine changes in the main four diseases at epidemiological level: sarcoidosis, Langerhans cell histiocytosis, hereditary hemochromatosis, and systemic amyloidosis. Recommendations to endocrinologists for hormone work-up and management of patients with each of these conditions are provided.

Langerhans cell histiocytosis: Case report and literature review

La histiocitosis de células de Langerhans comprende un grupo heterogéneo de enfermedades inflamatorias cuyos principales componentes celulares son las células dendríticas y los macrófagos. El infiltrado inflamatorio puede afectar la piel y otros órganos, y el resultado clínico varía de leve a letal, dependiendo del subconjunto de células involucradas y el compromiso multisistémico. La demora en el diagnóstico puede ocurrir debido a su presentación inespecífica y a que los médicos tratantes no suelen sospecharla. Se reporta el caso de una lactante mayor a la cual, a pesar de múltiples consultas con síntomas inespecíficos pero característicos de la enfermedad, solamente se le pudo hacer el diagnóstico gracias a los hallazgos histopatológicos.

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.

Central diabetes insipidus developing in a 6-year-old patient 4 years after the remission of unifocal bone Langerhans cell histiocytosis

A six-year-old boy was referred with a one-and-a-half months history of polyuria and polydipsia. At the age of two, he had a single lytic bone lesion in his femoral head, diagnosed as Langerhans cell histiocytosis (LCH) by biopsy at another hospital. As no other affected organs were detected and the affected bone lesion was self-limited, he was not followed up afterward and was doing well. He was diagnosed with diabetes insipidus (DI) by confirming hypernatremia (Na: 148 mEq/l) with hyperosmolar serum (s-Osm 298 mOSM/kg) and inappropriately diluted urine (u-Osm 205 mOSM/kg). His polyuria and polydipsia improved dramatically using the perioral diuretic hormone, and other pituitary functions were not impaired. Magnetic resonance imaging revealed an enlarged pituitary stalk. Sensitive and specific biomarkers of germ cell tumors, including alpha-fetoprotein, placental alkaline phosphatase, and β-hCG in the cerebrospinal fluid, were not detected, indicating relapse of LCH. Genetic analysis revealed a BRAF V600E mutation in the primary bone lesion. We recommend systematic follow-up of patients with a history of LCH, even non-CNS single-system single-site disease, especially with BRAF V600E mutation.

Diagnosis and management of diabetes insipidus for the internist: an update

Diabetes insipidus is a disorder characterized by excretion of large amounts of hypotonic urine. Four entities have to be differentiated: central diabetes insipidus resulting from a deficiency of the hormone arginine vasopressin (AVP) in the pituitary gland or the hypothalamus, nephrogenic diabetes insipidus resulting from resistance to AVP in the kidneys, gestational diabetes insipidus resulting from an increase in placental vasopressinase and finally primary polydipsia, which involves excessive intake of large amounts of water despite normal AVP secretion and action. Distinguishing between the different types of diabetes insipidus can be challenging. A detailed medical history, physical examination and imaging studies are needed to detect the aetiology of diabetes insipidus. Differentiation between the various forms of hypotonic polyuria is then done by the classical water deprivation test or the more recently developed hypertonic saline or arginine stimulation together with copeptin (or AVP) measurement. In patients with idiopathic central DI, a close follow-up is needed since central DI can be the first sign of an underlying pathology. Treatment of diabetes insipidus or primary polydipsia depends on the underlying aetiology and differs in central diabetes insipidus, nephrogenic diabetes insipidus and primary polydipsia. This review will discuss issues and newest developments in diagnosis, differential diagnosis and treatment, with a focus on central diabetes insipidus.

A case of langerhans cell histiocytosis of the mandible that spontaneously regressed after biopsy in a child

In younger patients of LCH, we should consider that the effectiveness of follow-up without aggressive treatment for SS-type LCH in the oral and maxillofacial bone. However, there are very rare case in which an SS-type LCH recurred after showing a healing tendency. Regular follow-up must be performed even after healing.

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.