Intestinal Langerhans cell histiocytosis presenting with symptoms similar to inflammatory bowel disease: a case report.

Background: Langerhans cell histiocytosis is a rare disease characterized by the abnormal proliferation of Langerhans cells within a single organ or multiple organs. This case report aims to improve the knowledge of the presentation of gastrointestinal Langerhans cell histiocytosis to facilitate the diagnosis and management of this rare disorder. Case presentation: A 19-month-old female presented with repeatedly mucinous bloody stools. The abdominal ultrasound revealed a slightly enlarged spleen. The initial colonoscopy revealed chronic enteritis with a very early onset inflammatory bowel disease. After anti-inflammatory treatment without improvement, an intestinal biopsy was performed at The Forth Affiliated Hospital of Zhejiang University. The final intestinal biopsy and histopathology examination confirmed the presence of Langerhans cell histiocytosis. After diagnosis, additional lung and head imaging examinations revealed no abnormalities. Her condition improved gradually after being treated with chemotherapy (vincristine and prednisone) and molecular-targeted drug(dalafinil) treatment. Conclusion: The clinical symptoms of Langerhans cell histiocytosis involving the gastrointestinal tract are not specific and may resemble symptoms observed in inflammatory bowel disease and other primary gastrointestinal tumors. Therefore, in cases of infants presenting with inflammatory gastrointestinal symptoms that do not resolve after treatment, a biopsy is essential to obtain a differential diagnosis.

Langerhans cell histiocytosis in children with refractory diarrhoea and hypoalbuminaemia as the initial presentation: two case reports and a literature review.

Langerhans cell histiocytosis (LCH) involving the gastrointestinal tract is a rare condition for which clinical experience is limited. We describe the cases of two patients who initially presented with chronic diarrhoea, hypoproteinaemia, and intermittent fever. These findings suggest that in cases of refractory diarrhoea accompanied by recurrent hypoalbuminaemia, especially with abdominal rash, LCH should be considered. Gastrointestinal endoscopy, biopsy, and imaging studies are essential for obtaining a definitive diagnosis. This approach might be helpful for the early recognition of gastrointestinal tract involvement in LCH.

Identification and characterization of stromal-like cells with CD207+/low CD1a+/low phenotype derived from histiocytic lesions - a perspective in vitro model for drug testing.

BACKGROUND: Histiocytoses are rare disorders manifested by increased proliferation of pathogenic myeloid cells sharing histological features with macrophages or dendritic cells and accumulating in various organs, i.a., bone and skin. Pre-clinical in vitro models that could be used to determine molecular pathways of the disease are limited, hence research on histiocytoses is challenging. The current study compares cytophysiological features of progenitor, stromal-like cells derived from histiocytic lesions (sl-pHCs) of three pediatric patients with different histiocytoses types and outcomes. The characterized cells may find potential applications in drug testing. METHODS: Molecular phenotype of the cells, i.e. expression of CD1a and CD207 (langerin), was determined using flow cytometry. Cytogenetic analysis included GTG-banded metaphases and microarray (aCGH) evaluation. Furthermore, the morphology and ultrastructure of cells were evaluated using a confocal and scanning electron microscope. The microphotographs from the confocal imaging were used to reconstruct the mitochondrial network and its morphology. Basic cytophysiological parameters, such as viability, mitochondrial activity, and proliferation, were analyzed using multiple cellular assays, including Annexin V/7-AAD staining, mitopotential analysis, BrdU test, clonogenicity analysis, and distribution of cells within the cell cycle. Biomarkers potentially associated with histiocytoses progression were determined using RT-qPCR at mRNA, miRNA and lncRNA levels. Intracellular accumulation of histiocytosis-specific proteins was detected with Western blot. Cytotoxicyty and IC50 of vemurafenib and trametinib were determined with MTS assay. RESULTS: Obtained cellular models, i.e. RAB-1, HAN-1, and CHR-1, are heterogenic in terms of molecular phenotype and morphology. The cells express CD1a/CD207 markers characteristic for dendritic cells, but also show intracellular accumulation of markers characteristic for cells of mesenchymal origin, i.e. vimentin (VIM) and osteopontin (OPN). In subsequent cultures, cells remain viable and metabolically active, and the mitochondrial network is well developed, with some distinctive morphotypes noted in each cell line. Cell-specific transcriptome profile was noted, providing information on potential new biomarkers (non-coding RNAs) with diagnostic and prognostic features. The cells showed different sensitivity to vemurafenib and trametinib. CONCLUSION: Obtained and characterized cellular models of stromal-like cells derived from histiocytic lesions can be used for studies on histiocytosis biology and drug testing.

Metagenomic sequencing expedites diagnosis of disseminated BCG in an infant with BRAFV600E mutation.

INTRODUCTION: Disseminated bacillus Calmette-Guérin (BCG) disease is a rare but serious BCG complication in children. Early diagnosis and timely interventions are essential to improve prognosis. However, its manifestations can closely mimic those of Langerhans cell histiocytosis (LCH), which usually leads to a high rate of misdiagnoses. Herein we report the first case of successful application of biopsy tissue metagenomic next-generation sequencing (mNGS) in the differential diagnosis of disseminated BCG disease and LCH. CASE STUDY: A 5-month-old female infant was transferred to our center for the treatment of paroxysmal cough, intermittent hematochezia and trunk rash. Examination on admission showed moderate anemia, erythropenia, thrombocytopenia and hepatosplenomegaly. The immunohistochemistry of her intestinal biopsy samples showed CD1a (+) and Langerin (+). Genetic testing of both peripheral blood and bone marrow samples suggested BRAFV600E mutation. Hence, she was initially diagnosed with LCH. However, no improvement was observed after a course of systemic chemotherapy. The left axillary lymph node and colonic mucosal biopsy specimens were sent for mNGS which resulted in sequence reads of Mycobacterium bovis-BCG. Triple antimycobacterial therapy was started according to the diagnosis. RESULTS: The diagnosis of this case was corrected as disseminated BCG disease by mNGS. Currently, she is doing well clinically and continues to follow-up at our outpatient clinic. CONCLUSIONS: This case suggests that mNGS is a valuable tool in the differential diagnosis of disseminated BCG disease and LCH, which can improve the early diagnosis rate of disseminated BCG disease.

Phase 2 study using low dose cytarabine for adult patients with newly diagnosed Langerhans cell histiocytosis.

Langerhans cell histiocytosis (LCH) lacks a standardized first-line therapy. This single-center, phase 2 prospective study (NCT04121819) enrolled 61 newly diagnosed adult LCH patients with multisystem or multifocal single system disease from October 2019 to June 2022. Subcutaneous cytarabine (100 mg/m2 for 5 days) was administered in 35-day cycles for 12 total cycles. The primary endpoint was event-free survival (EFS). The median age was 33 years (range 18-66). Twelve patients (19.7%) had liver involvement, of which 2 also had spleen involvement. Among 43 patients undergoing next-generation sequencing, BRAF alterations (44.2%) were most frequent, followed by TP53 (16.3%), MAP2K1 (14.0%) and IDH2 (11.6%). MAPK pathway alterations occurred in 28 patients (65.1%). The overall response rate was 93.4%, with 20 (32.7%) achieving complete response and 37 (60.7%) partial response. After a median 30 months follow-up, 21 (34.4%) relapsed without deaths. Estimated 3-year OS and EFS were 100.0% and 58.5%, respectively. Multivariate analysis identified ≥3 involved organs (P = 0.007; HR 3.937, 95% CI: 1.456-9.804) and baseline lung involvement (P = 0.028; HR 2.976, 95% CI: 1.126-7.874) as poor prognostic factors for EFS. The most common grade 3-4 toxicities were neutropenia (27.9%), thrombocytopenia (1.6%), and nausea (1.6%). In conclusion, cytarabine monotherapy is an effective and safe regimen for newly diagnosed adults, while baseline lung or ≥3 involved organs confers poor prognosis.

[Isolated liver involvement in Langerhans cell histiocytosis: A case report]. / Localisation hépatique isolée d'une histiocytose langerhansienne : à propos d'un cas.

Langerhans cell histiocytosis (LCH) is a disease whose physiopathology remains unclear, involving both inflammatory processes and clonal proliferation. It is observable at any given age, although about ten times more frequent in children than adults. Hepatic involvement is not rare, mostly part of a systemic disease, and linked to a poor prognosis. We report here a case of LCH with solitary hepatic involvement in a 74 year-old patient. This case demonstrated molecular anomaly of the MAPK pathway, BRAF N486_P490del. Through this observation, we precise the epidemiological and histological aspects and diagnostic criteria of this rare disease.

[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.

Concurrent Langerhans Cell Histiocytosis and Acute Myeloid Leukemia Without Clonal Relationship.

This case report describes a woman in her 30s who had been treated with chemotherapy and presented with Langerhans cell histiocytosis and acute myeloid leukemia (AML).

Endocrine features of Langerhans cell histiocytosis in paediatric patients: A 30-year review.

Langerhans cell histiocytosis (LCH) is a rare proliferative disorder characterised as an inflammatory myeloid neoplasia. Endocrine manifestations of LCH, particularly central diabetes insipidus (CDI), have been described from the 1940s, through case studies and small cohort analyses. There are limited Australian paediatric data described in recent literature. AIM: To document the incidence of endocrine features in paediatric patients with LCH, treated at a tertiary paediatric centre in Victoria, Australia. METHODS: Retrospective chart review of electronic medical records and oncology database of patients with LCH managed at a tertiary paediatric centre. Patients were excluded if a biopsy did not suggest LCH or if records were incomplete. RESULTS: One hundred seventy-one patients were identified and 141 records of patients diagnosed with LCH over the last 30 years were assessed for endocrinopathies, from diagnosis to last documented follow-up. Mean age at diagnosis was 5 years 8 months. Of these, 15% (n = 21) had CDI, 7% had growth hormone deficiency (GHD) (n = 10) and 8% (n = 11) had more than one endocrinopathy noted during follow-up. Forty percent (n = 57) were pre-pubertal at the time of audit or upon discharge from tertiary services. CONCLUSIONS: Ongoing pituitary assessment, in addition to CDI, is required to detect evolving deficiencies of GHD and gonadotropins as these can be subtle, late or missed. Close follow-up of growth and progression through puberty, even if discharged from tertiary care, is essential.

A Case of Uncommon S100-Negative CD1a-Positive Histiocytosis in a 9-Year-Old Boy: Clinical Presentation, Histopathologic Features, and Successful Treatment Approach.

ABSTRACT: Immunohistochemically, histiocytosis differentiating into Langerhans cells is typically characterized by the expression of CD1a, S100, and varying degrees of Langerin. However, CD1a-positive but S100-negative histiocytosis is extremely rare in clinical practice. We present a case of a 9-year-old boy with multiple erythematous to brown dome-shaped nodules. Histopathologic examination revealed dermal infiltrates of histiocytic cells, exhibiting a distinctive immunohistochemical profile of CD68+, S100-, CD1a+, and Langerin-. This exceptional case may contribute to our understanding of the etiology and differentiation processes of histiocytic proliferative disorders.

Early chemotherapeutic intervention to avoid thyroidectomy in pediatric Langerhans cell histiocytosis with thyroid involvement accompanying tracheal stenosis: a report of two cases.

Thyroid involvement is rare in pediatric Langerhans cell histiocytosis (LCH). It may cause airway narrowing, leading to acute-onset respiratory distress. Severe cases may require emergent surgical interventions such as thyroidectomy, which should be avoided in children due to higher rates of complication, particularly in infancy. There is currently no consensus on the indications for surgical treatment in LCH with thyroid involvement. In this report, we describe the cases of two children who presented with tracheal stenosis caused by thyroid LCH, both of which were successfully treated by early induction of chemotherapy, and one of which was also treated for a shorter duration. Mutation analysis detected in-frame deletions of BRAF exon 12 in both cases. These cases suggest that timely diagnosis and administration of chemotherapy may alleviate severe airway obstruction and reduce the need for thyroidectomy in pediatric patients with thyroid LCH.

Concurrent Langerhans cell histiocytosis and acute myeloid leukemia: A rare presentation of a rare case.

A 72-year-old woman with no significant past medical history was admitted to the hospital for new-onset of leukocytosis with neutropenia, anemia, and thrombocytopenia, as well as a pruritic skin eruption. She was found to have acute myeloid leukemia (AML) with myelomonocytic differentiation. Her skin eruption consisted of widespread hemorrhagic crusted papules on the scalp and trunk. A skin biopsy was performed, which revealed a proliferation of mononuclear cells in the dermis with prominent epidermotropism and positive expression of CD1a and langerin (CD207), supporting a diagnosis of Langerhans cell histiocytosis (LCH). LCH is an uncommon proliferative disorder of activated Langerhans cells, which generally presents in children. In adults, it is exceptionally infrequent. Associated malignancies and rare reports of AML developing in subsequent years after an initial presentation of LCH have been described. Here we present an unusual concurrent presentation of LCH and AML in an adult.

Langerhans Cell Histiocytosis Presenting as Anterior Neck Mass in a Child: A Case Report.

Thyroid involvement in Langerhans Cell Histiocytosis (LCH) is rare. We report a 10-year-old Filipino male who presented with a rapidly enlarging goiter. Computed tomography scan showed thyroid and bilateral submandibular masses with malignant features, pulmonary blebs and hepatic cysts. Ultrasound-guided core needle biopsy findings were consistent with LCH and chemotherapy was initiated. This case demonstrates that LCH should be considered in patients with goiter. Multidisciplinary management is warranted to achieve proper diagnosis and institute timely treatment.

Bronchoalveolar cytokine profile differentiates Pulmonary Langerhans cell histiocytosis patients from other smoking-related interstitial lung diseases.

BACKGROUND: Pulmonary Langerhans cell histiocytosis (PLCH) is a rare interstitial lung disease (ILD) associated with smoking, whose definitive diagnosis requires the exclusion of other forms of ILD and a compatible surgical lung biopsy. Bronchoalveolar lavage (BAL) is commonly proposed for the diagnosis of ILD, including PLCH, but the diagnostic value of this technique is limited. Here, we have analyzed the levels of a panel of cytokines and chemokines in BAL from PLCH patients, in order to identify a distinct immune profile to discriminate PLCH from other smoking related-ILD (SR-ILD), and comparing the results with idiopathic pulmonary fibrosis (IPF) as another disease in which smoking is considered a risk factor. METHODS: BAL samples were collected from thirty-six patients with different ILD, including seven patients with PLCH, sixteen with SR-ILD and thirteen with IPF. Inflammatory profiles were analyzed using the Human Cytokine Membrane Antibody Array. Principal component analysis (PCA) was performed to reduce dimensionality and protein-protein interaction (PPI) network analysis using STRING 11.5 database were conducted. Finally, Random forest (RF) method was used to build a prediction model. RESULTS: We have found significant differences (p < 0.05) on thirty-two cytokines/chemokines when comparing BAL from PLCH patients with at least one of the other ILD. Four main groups of similarly regulated cytokines were established, identifying distinct sets of markers for each cluster. Exploratory analysis using PCA (principal component analysis) showed clustering and separation of patients, with the two first components capturing 69.69% of the total variance. Levels of TARC/CCL17, leptin, oncostatin M (OSM) and IP-10/CXCL10 were associated with lung function parameters, showing positive correlation with FVC. Finally, random forest (RF) algorithm demonstrates that PLCH patients can be differentiated from the other ILDs based solely on inflammatory profile (accuracy 96.25%). CONCLUSIONS: Our results show that patients with PLCH exhibit a distinct BAL immune profile to SR-ILD and IPF. PCA analysis and RF model identify a specific immune profile useful for discriminating PLCH.

Antemortem cytologic diagnosis of pulmonary Langerhans cell histiocytosis in a cat.

Feline pulmonary Langerhans cell histiocytosis (FPLCH) is a rare histiocytic proliferative disease of middle-aged to older domestic cats. Langerhans cells in the terminal airways proliferate and infiltrate the interstitium and the airways to a lesser degree, widely effacing normal parenchyma. Historically, definitive diagnosis has required postmortem evaluation where pulmonary lesions have a classic gross and histologic morphology. Here, we present the first documented antemortem diagnosis of FPLCH using bronchoalveolar lavage (BAL) cytology and immunocytochemistry (ICC) in a 9-year-old British shorthair mix. The cat had a 3-month history of respiratory difficulty that was refractory to steroids and antimicrobials. Pulmonary radiographs had marked diffuse changes with a complex bronchointerstitial and micronodular pattern. BAL cytology revealed neutrophilic inflammation and markedly increased histiocytes with morphology distinct from typical pulmonary macrophages. ICC characterized histiocytes as CD1a+ /E-cadherin+ /CD11b- /PanCK- , consistent with a Langerhans cell phenotype. The cat was humanely euthanized due to poor prognosis and presented for necropsy. Gross, histopathologic, immunophenotypic, and ultrastructural findings confirmed a diagnosis of FPLCH. Proliferative cells were E-cadherin+ /Iba-1+ /CD18+ /CD1a+ /CD5+ /MHCII+ /CD204- /CD4- ; transmission electron microscopy identified the presence of Birbeck granules in the proliferating histiocytes, consistent with previous reports of FPLCH.

Successful treatment of Langerhans cell histiocytosis in an infant with vemurafenib: a case report and literature review.

Langerhans cell histiocytosis (LCH) is a histiocytic neoplasm characterized by a mass of CD1a + CD207 + histiocytes, exhibiting a diverse range of clinical manifestations from a self-healing rash or single bone destruction to multi-organ disease with potentially fatal consequences. The identification of MAPK signaling pathway activation, particularly BRAFV600E mutations, has propelled targeted therapy into the forefront of therapeutic research for LCH. Several studies have demonstrated that Vemurafenib, a BRAF inhibitor, exhibits superior clinical efficacy and a more favorable safety profile in LCH. Herein, in this case report, we present a good response to vemurafenib in an infant diagnosed with multisystem Langerhans cell histiocytosis (LCH).

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.

Single-system pulmonary langerhans cell histiocytosis with only tracheobronchial involvement: a case report.

BACKGROUND: Pulmonary Langerhans cell histiocytosis (PLCH) only with airway involvement manifested as diffuse thickening of the tracheobronchial walls is rare. CASE REPORT: A 26-year-old male was admitted to the hospital with progressive wheezing, cough, and a source of blood in sputum after activity. He had no history of smoking. Chest computed tomography showed airway stenosis of different degrees with tracheobronchial wall thickening, and fiberoptic bronchoscopy demonstrated multiple nodular neoplasms in tracheobronchial, while the pulmonary parenchyma was normal. The patient's condition partially improved after excision of partial lesions by fiberoptic bronchoscope. Histopathological results showed that CD1a and S-100 immunohistochemical staining was positive, and the molecular pathological results suggested that the BRAF V600E mutation, thus confirming the diagnosis of PLCH. The treatment of partial resection and systemic chemotherapy is effective. CONCLUSIONS: The possibility of PLCH needs to be considered when diffuse tracheobronchial lesions without lung parenchyma involvement are encountered, which provides experience for early clinical diagnosis and adequate treatment.