Management of adult patients with Langerhans cell histiocytosis: recommendations from an expert panel on behalf of Euro-Histio-Net

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.

Solitary Skull Langerhans Cell Histiocytosis Presenting With a Pus Draining Fistula: An Unusual Presentation and Review of Literature

Langerhans cell histiocytosis (LCH) is a rare condition in adults, especially when it is limited to a single area of the skull, known as solitary calvarial involvement. In this case report, we present a unique instance of LCH affecting the parietal bone with a pus-draining fistula. This is a rare and unusual presentation at this location, which has been scarcely reported in medical literature. A 30-year-old woman with no prior comorbidity presented with complaints of headache that persisted for a year. She also had swelling on her scalp and a yellowish discharge for 3 weeks, but no neurological problems were observed. Radiology revealed thinning of the calvaria, with ragged margins along the inner table, multiple focal erosions, and involvement of overlying soft tissue and bony sequestrum. The patient underwent biparietal craniotomy and excision of the lesion. The histopathology report showed LCH. After 8 months of follow-up, there was no recurrence. The management of solitary calvarial involvement by LCH with masquerading presentation as a scalp infection can be achieved through complete excision of the lesions, resulting in a favorable outcome.

Toxicological evaluation of a fish oil concentrate containing Very Long Chain Fatty Acids

Very long chain fatty acids (VLCFA) have a chain length ≥24 carbons. Fish contain low levels of these fatty acids. A commercial oil called EPAX® Evolve 05 with an up-concentration of VLCFAs of approximately 10 times, has been developed as a dietary supplement by Epax Norway AS. A series of toxicological studies were performed using mice and rats to determine the safety and toxicity of repeat dosing with a gavage administered VLCFA formulation. The results suggest transient lipid accumulation in kidneys and liver. Lipid accumulation was seen with the test item and with the soya control but was not dose related. Liver and kidney lipid accumulation, whilst present in 14- day repeat dose study, was absent in a 90-day rat study. No treatment-effect was seen in urine analysis in any of the studies. No treatment-related effects were seen with a functional observation battery, ophthalmological examination, haematology, urine analysis, oestrus cycle, thyroid hormones, organ weight, or histopathology. In the 90-day study the liver enzymes ALP, AST and ALT were statistically significantly increased with test item but within control values. There were no associated histological findings in the liver suggesting there was no toxic effect and the normalisation of values for all liver enzymes in the recovery groups suggests an adaptive response rather than a prevailing toxic response. The no-observed-adverse-effect level (NOAEL) was determined as 1200 mg VLCFA/kg b.w./day.

Molecular Mutations in Histiocytosis: A Comprehensive Survey of Genetic Alterations

Histiocytosis represents a group of uncommon disorders characterized by the abnormal accumulation of specialized immune cells, such as macrophages, dendritic cells, or monocyte-derived cells, in various tissues and organs. Over 100 distinct subtypes have been documented, each displaying a broad spectrum of clinical presentations and histological characteristics. Till today, histiocytosis has been addressed through a combination of chemotherapy, radiotherapy, and surgery, with varying responses from individual patients. Due to its atypical symptoms, it has been prone to misdiagnosis. Advances in our understanding of the cellular and molecular aspects of these conditions are paving the way for improved diagnostic methods and targeted therapies. Researchers have extensively investigated various mutations in patient samples. However, no paper has yet provided a comprehensive summary of the collective analysis of mutations and pathways. Hence, this paper consolidates research efforts that specifically concentrate on gene mutations identified in patient samples of different subtypes of histiocytosis. These insights are essential for developing targeted therapies and improving diagnosis. Further, it provides potential insights to enhance the development of more effective therapeutic approaches for rare diseases.

Late Diagnosis of Langerhans Cell Histiocytosis by Skin Biopsy in a Lung Transplant Candidate Patient

We present the case of a lung transplant candidate under veno-venous membrane oxygenation assistance (VV ECMO) whose diagnosis of emphysema of undetermined etiology was redefined as Langerhans cell histiocytosis (LCH) due to a scalp skin biopsy performed years after the beginning of his respiratory symptoms. A 20-year-old patient started three years before his admission with progressive dyspnea leading to a diagnosis of bullous emphysema of undetermined cause, which evolved into respiratory failure and evaluation for bilateral lung transplant. Three years later, he developed bilateral pneumonia requiring mechanical ventilation. When refractory hypoxemia ensued, he had to be placed on VV ECMO. Under these conditions, he was transferred to our center and listed for a bilateral pulmonary transplantation. Forty-eight hours after admission, and due to intense polyuria, central diabetes insipidus was diagnosed. In this clinical context, the presence of cutaneous lesions on the scalp was reconsidered and biopsied under the presumption of possible LCH, with pathology analysis confirming the diagnosis. He continued to be assisted with VV ECMO for 66 more days as a bridge to transplantation, developing multi-organ failure and passing away before a donor organ was available. The diagnosis of LCH should be considered in any adult patient with bullous emphysema of undetermined cause. Given the possibility of early therapeutic interventions, the search for its clinical associations (e.g., diabetes insipidus and/or skin lesions) should be a systematic part of the etiologic workup. The availability of skin specimens to reach a diagnosis makes its thorough search an important part of the diagnostic approach.

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.

Long-term outcomes among adults with Langerhans cell histiocytosis

Advances in the treatment of Langerhans cell histiocytosis (LCH) have resulted in a growing survivor population. There is a lack of data on long-term outcomes among adults with LCH. We conducted a retrospective record review of 219 adults (aged ≥18 years) with LCH. Most common presentation was multisystem (34.2%), followed by single-system pulmonary (32%), unifocal (28.3%), and single-system multifocal (5.5%) LCH. Risk organ involvement (the liver, spleen, or bone marrow) was seen in 8.7% of cases, and 40 of 88 (45.5%) tested cases were BRAFV600E. At a median follow-up of 74 months, 5-year progression-free survival (PFS) was 58.3% and estimated median PFS was 83 months. Median overall survival (OS) was not reached; 5- and 10-year OS rates were 88.7% and 74.5%, respectively. Risk organ involvement was associated with worse PFS (hazard ratio [HR], 4.5) and OS (HR, 10.8). BRAFV600E was not associated with risk organ involvement or survival. When compared with matched unaffected US population, individuals with LCH had a significantly higher risk of overall mortality (standardized mortality ratio [SMR], 2.66), specifically among those aged <55 years at diagnosis (SMR, 5.94) and those with multisystem disease (SMR, 4.12). Second cancers occurred in 16.4% cases, including diverse hematologic and solid organ malignancies. LCH-associated deaths constituted 36.1% of deaths and occurred within 5 years of diagnosis. After 5 years, non-LCH causes of death, including second cancers, chronic obstructive pulmonary disease, and cardiovascular diseases, predominated. Our study highlights, to our knowledge, for the first time, that adults with LCH experience early and late mortality from non-LCH causes and the need for development of targeted survivorship programs to improve outcomes.

Pulmonary Langerhans cell histiocytosis diagnosed using transbronchial lung cryobiopsy: A case report

A 63-year-old Japanese woman with multiple cysts in both lungs on chest computed tomography (CT) was referred to our hospital after a thorough examination, including a transbronchial lung biopsy (TBLB), failed to provide a diagnosis. Based on the findings on chest CT and pathological examination of the bronchoalveolar lavage fluid and transbronchial lung cryobiopsy (TBLC) specimen, the patient was diagnosed with pulmonary Langerhans cell histiocytosis (PLCH). TBLC may replace TBLB as the main diagnostic technique for PLCH, although further studies are required to determine the usefulness of TBLC for the diagnosis of PLCH.

Adult-onset Langerhans cell histiocytosis of bone: A case series highlighting a rare entity

Langerhans cell histiocytosis (LCH) is a neoplastic disorder derived from LCH precursor cells that can manifest as a single-system disease or a multisystem disorder. While extensively studied in children, LCH has received less attention in adult patients. We aimed to investigate the pathology and clinical course of LCH in adults presenting with a bone lesion. Cases of osseous LCH diagnosed in patients ≥18 in our center were analyzed. Histologic slides were reviewed, and clinical data were collated. Molecular analysis for BRAF mutation was performed in a subset. Twelve osseous LCH cases with classic morphology and CD1a+/S100+ immunophenotype were identified. Tumors occurred in six females and five males with a median age of 34 years (range: 18-77 years) and involved the craniofacial bones (4), pelvis (3), spine (2), appendicular skeleton (2), and rib (1). Radiographically, tumors appeared as ill-defined lytic lesions, often accompanied by cortical erosion and soft tissue extension, with pain being the most common presentation. On staging work-up with available data, two patients had multifocal bone lesions, two had multi-system disease, and four had solitary lesions. Two patients had prior or concurrent neoplasms, and 63 % of patients (5 out of 8) had a history of smoking. BRAF mutational analysis performed in six cases revealed a BRAFV600E mutation in one, negative result in one, and failed in four archived specimens. Our study highlights the importance of performing staging in patients with adult-onset LCH presenting as a bone lesion, as the clinical extent of the disease can vary widely among individuals.

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.

[Histiocytosis]

Histiocytosis is a group of rare diseases characterized by inflammation and accumulation of cells derived from monocytes and macrophages in different tissues. The symptoms are highly variable, from mild forms with involvement of a single organ to severe multisystem forms that can be life compromising. The diagnosis of histiocytosis is based on the clinic, radiological findings and pathological anatomy. A biopsy of the affected tissue is recommended in all cases as it may have therapeutic implications. During the last decade, some mutations have been identified in the affected tissue that condition activation of the MAPK/ERK and PI3K/AKT pathway, in a variable proportion depending on the type of histiocytosis. In this review we mainly focus on Langerhans Cell Histiocytosis, Erdheim-Chester Disease and Rosai-Dorfman Disease.

Adult multisystem Langerhans cell histiocytosis with cutaneous involvement manifesting as extensive flexural erosions

Langerhans cell histiocytosis is a great imitator of other diseases with an often-delayed diagnosis leading to a concerning delay in commencing treatment. We present the case of a male who was previously diagnosed with Hailey-Hailey disease, in whom several treatment options had failed, was referred to the dermatology team for evaluation of a 3-month atypical, extensive, painful and pruritic cutaneous flexural eruption. On systems review, he reported a 2-year history of polyuria and polydipsia. Repeat skin biopsy revealed a prominent histiocytic infiltrate on histopathology with corresponding positive expression of Langerin (CD207), S100, CyclinD1 and p-ERK on immunohistochemistry staining. An MRI of the brain demonstrated posterior pituitary enhancement. The clinical presentation, biopsy and investigations confirmed a diagnosis of a multisystem Langerhans cell histiocytosis, which resulted in longstanding patient morbidity. With considerable multidisciplinary teamwork, a gradual and sustained resolution of his lesions, pain, polyuria and polydipsia was achieved.

Langerhans cell histiocytosis of the frontal bone with unexpected manifestations: Rare case report

INTRODUCTION

Langerhans cell histiocytosis (LCH) is a disease caused by clonal expansion of myeloid precursors that differentiate into specialized dendritic cells.

PRESENTATION OF CASE

A 21-year-old female came to our hospital complaining of tachycardia, high temperature, and tumor formation in the frontal region with a fistula. The examination of the thyroid gland and other systems was normal. The radiological investigations showed a severe lytic osseous lesion with aggressive destruction of the bone. The ultrasound imaging of the thyroid gland revealed that the thyroid was generally hypoechoic and heterogeneous because of many small hypoechoic focuses. In addition, the blood perfusion increased in the gland. The laboratory investigations were within normal expect C-reactive protein, free T4, and TSH. The surgery was indicated. The patient underwent an excision of the mass by a specialist in neurosurgery. The histopathological examination of the excised mass revealed LCH (eosinophilic granuloma). After 6 months, the patient underwent cranioplasty. The follow-up was uneventful for 3 months until the patient suffered from hyperthyroidism.

DISCUSSION

LCH can form in any part of the body, and cause many symptoms depending on its location. Even though hyperthyroidism is a rare and unexpected symptom of LCH.

CONCLUSION

LCH is a disease with broad-spectrum manifestations, so it should be a differential diagnosis in bone, thyroid, skin, and other organ lesions. In addition, thyroid ultrasonography and laboratory investigations are important methods to estimate thyroid functions and determine the clinical classification of the disease.

A solitary osteolytic lesion with pathological fracture in the cervical spine - a case report

BACKGROUND

Langerhans cell histiocytosis (LCH) is a rare disorder. The treatment options vary depending on how many organs are involved and how extensive the disease is. In this report, a case of LCH with isolated 6th cervical vertebra (C6) collapse was presented. This case was treated with anterior corpectomy and instrumented fusion, followed by local radiotherapy (RT), with a good clinical outcome up to postoperative six months.

CASE PRESENTATION

This was a 47-year-old female patient with a complaint of neck pain and bilateral shoulder pain for two months before consultation. She was initially treated with analgesics, but the pain was persistent. Further radiological evaluations revealed an osteolytic lesion within the C6 vertebral body with a pathological fracture. Magnetic resonance imaging (MRI) with contrast of the cervical spine revealed diffused hypointense signal changes on the T1-weighted images and hyperintense signal changes on the T2-weighted images in the C6 vertebral body, with significant contrast-enhanced infiltration signals. Furthermore, in positron emission tomography-computed tomography (PET-CT), focal hypermetabolism and abnormal uptake signals were seen only in the C6 vertebral body. The patient underwent an anterior cervical corpectomy with instrumented fusion. The histopathological results confirmed the diagnosis of LCH. The patient reported significant pain relief on postoperative day one. Moreover, she was treated by local RT at postoperative one month. Good clinical outcomes were achieved in the form of no pain and recovery in neck mobility up to postoperative six months. No evidence of recurrence was observed at the final follow-up.

CONCLUSIONS

This case report describes a treatment option for a solitary C6 collapse with LCH managed by anterior corpectomy and instrumented fusion, followed by local RT, with a good clinical outcome at postoperative six months. More studies are needed to elucidate whether such a treatment strategy is superior to surgery or RT alone.

Imaging Phenotypes and Evolution of Hepatic Langerhans Cell Histiocytosis on CT/MRI: A Retrospective Study of Clinical Cases and Literature Review

(1) Background: pathological changes in hepatic Langerhans cell histiocytosis (LCH) have been observed; however, corresponding imaging findings can appear vague to physicians and radiologists. The present study aimed to comprehensively illustrate the imaging findings of hepatic LCH and to investigate the evolution of LCH-associated lesions. (2) Methods: LCH patients with liver involvement treated at our institution were retrospectively reviewed along with prior studies in PubMed. Initial and follow-up computed tomography (CT) and magnetic resonance imaging (MRI) were systematically reviewed, and three imaging phenotypes were created based on the lesion distribution pattern. Clinical features and prognoses were compared among the three phenotypes. Liver fibrosis was evaluated visually on T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI), and apparent diffusion coefficient (ADC) values of the fibrotic areas were measured. Descriptive statistics and a comparative analysis were used to analyze the data. (3) Results: based on the lesion distribution pattern on CT/MRI scans, patients with liver involvement were categorized as the disseminated lesion phenotype, scattered lesion phenotype, and central periportal lesion phenotype. Patients with scattered lesion phenotype were typically adults, and only a few of them had hepatomegaly (n_present = 1, 1/6, 16.7%) and liver biochemical abnormalities (n_present = 2, 2/6, 33.3%); patients with central periportal lesion phenotype were typically young children, and hepatomegaly and biochemical abnormalities were more apparent in these patients than those with another phenotype; and those with the disseminated lesion phenotype were found in all age groups, and the lesions evolved rapidly on medical imaging. Follow-up MRI scans show more details and can better document the evolution of lesions than CT. T2-hypointense fibrotic changes, including the periportal halo sign (n_present = 2, 2/9, 22.2%), patchy liver parenchyma changes (n_present = 6, 6/9, 66.7%), and giant hepatic nodules close to the central portal vein (n_present = 1, 1/9, 11.1%), were found, while fibrotic changes were not observed in patients with the scattered lesion phenotype. The mean ADC value for the area of liver fibrosis in each patient was lower than the optimal cutoff for significant fibrosis (METAVIR Fibrosis Stage ≥ 2) in a previous study that assessed liver fibrosis in chronic viral hepatitis. (4) Conclusions: The infiltrative lesions and liver fibrosis of hepatic LCH can be well characterized on MRI scans with DWI. The evolution of these lesions was well demonstrated on follow-up MRI scans.

Possible involvement of CXCR3-CXCR6 + CD4 + T cells in Langerhans cell histiocytosis

INTRODUCTION

Langerhans cell histiocytosis (LCH) is a condition characterized by proliferation of Langerhans cells and wide-range pathologies, ranging from single granulomatous lesions to multi-organ involvement, associated with tissue destruction. LCH pathogenesis remains obscure although association with interleukin (IL)-17A has been reported. We report here a case that illustrates the potential pathogenic role of helper T17 (Th17) cells in LCH-related bone destruction.

MATERIALS AND METHODS

The patient was a 66-year-old woman. The clinical course included craniectomy and bone mass excision in X-9, diagnosis of LCH confirmed by histopathology, followed by 26-month chemotherapy. In August X, the patient was diagnosed with complete central diabetes insipidus. Symptoms improved after treatment with desmopressin. Pituitary magnetic resonance imaging showed swelling extending from the suprasellar region to the pituitary stalk, suggestive of LCH recurrence. This was followed by chemotherapy combined with mercaptopurine hydrate.  RESULTS: Subsequent peripheral blood lymphocyte analysis showed marked increase in activated Th17 cells (CXCR3^-CXCR6⁺ CD4⁺ T cells). Double staining for CD4 and IL-17 by immunofluorescence of pathological tissue samples obtained during temporal bone mass excision, which confirmed the diagnosis of LCH in X-9, showed areas of combined presence of CD4-positive cells and IL-17-positive cells. Chemotherapy resulted in size reduction of the pituitary lesion and decrease in peripheral blood-activated Th17 cells.

CONCLUSIONS

We found abundant peripheral blood-activated Th17 cells and high percentages of IL-17-producing cells in osteolytic bone lesions in LCH. This finding, together with the decrease in peripheral blood-activated Th17 cells following chemotherapy, suggests the potential involvement of activated Th17 cells in LCH-related osteolysis.

Outcomes of liver transplantation in children with Langerhans cell histiocytosis: Experience from a quaternary care center

BACKGROUND

Langerhans cell histiocytosis (LCH) is a rare but important cause of end-stage liver disease in children. Conventional chemotherapeutic agents that are otherwise the standard-of-care in LCH may be counterproductive in patients with hepatic decompensation. Furthermore, the precise role of liver transplantation (LT) in the management of LCH remains unclear.

METHODS

Review of a prospectively collected database (January 2014 to December 2020) of children with liver disease was performed. All clinical details of patients with LCH managed at our center were collected and data analyzed. Based on the outcomes, a management algorithm was proposed.

RESULTS

Of the eight (five male) patients referred to our unit, six (75%) underwent LT (four and two for compensated and decompensated cirrhosis, respectively). Median age at diagnosis of LCH was 25 (range: 9-48) months. Two patients, who had previously completed LCH-specific chemotherapy, underwent upfront LT for compensated cirrhosis. Other two patients with compensated cirrhosis showed evidence of active disease. They underwent LT following completion of chemotherapy. Two children with decompensated cirrhosis also had evidence of active disease and were started on modified chemotherapy Both of them had progression of liver disease while on chemotherapy. Hence, an urgent LT was performed which was followed by completion of chemotherapy in these patients. On a median follow-up of 30.5 (10.5-50) months, all post-LT patients were alive with stable graft function and showed no disease recurrence.

CONCLUSION

We demonstrate that an algorithmic approach, along with newer chemotherapeutic agents, results in excellent outcomes in LCH patients with liver involvement. Larger multicentric studies on this rare disease are, however, needed to validate our findings.

Diagnosis and treatment of isolated rib Langerhans cell histiocytosis in an adult: A case report

Langerhans cell histiocytosis (LCH) was first proposed in 1987 to define the disorder characterized by the proliferation of abnormal Langerhans cells. It is more likely to occur in children younger than 15 years of age. Single-site and single-system LCH of rib is rare in adults. We present a rare case of isolated rib LCH in a 61-year-old male patient and expound the diagnosis and treatment of the disease. A 61-year-old male patient who presented with a 15-day history of dull pain in the left chest was admitted to our hospital. PET/CT image showed obvious osteolytic bone destruction and abnormal fluorodeoxy-glucose (FDG) uptake (maximum standardized uptake value: 14.5) in the right fifth rib with local soft tissue mass formation. The patient was eventually confirmed the diagnosis of LCH by immunohistochemistry stain and treated with rib surgery. A thorough review of the literature regarding diagnosis and treatment of LCH is presented in this study.

Biomodulatory therapy induces durable remissions in multi-system Langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH) is rare hematological neoplasia originating from the aberrant proliferation of CD207-positive dendritic cells. Refractory multi-system LCH is difficult to treat necessitating the continuous development of different salvage therapies. At our medical center, eleven patients (age 11 months to 77 years) with multi-system LCH were treated on a compassionate use basis with metronomic biomodulation therapy (MBT) involving the daily oral application of low-dose trofosfamide, etoricoxib, pioglitazone and low-dose dexamethasone. Overall, four patients including two heavily pretreated pediatric patients achieved ongoing complete remission. Moreover, partial disease remission was observed in three patients, and four patients attained stable disease. MBT demonstrated high activity against multi-system LCH even in patients, refractory to multiple systemic chemotherapies. Further confirmation of efficacy should be systematically evaluated in prospective trials.

Langerhans cell histiocytosis in adults: literature review

Langerhans cells histiocytosis is a variant of malignant histiocytosis. The course and symptoms vary. patients with localized forms have a better prognosis, because local therapy is effective. patients with multifocal forms of histiocytosis receive systemic drug therapy, which cures some of the patients. This review provides up-to-date data about typical presentation of the organ involvement, diagnosis, course and therapy of various forms of Langerhans cells histiocytosis.

Posterior Focal Curettage and Spine Stability Reconstruction by Temporary Pedicle Screw Fixation in Children With Collapsed Vertebrae due to Eosinophilic Granuloma

STUDY DESIGN

Retrospective case series.

OBJECTIVES

To evaluate the efficacy of growth-preserving posterior spinal column reconstruction surgery in children with collapsed vertebral eosinophilic granuloma (EG).

METHODS

We retrospectively reviewed 15 confirmed cases of vertebral EG who met the inclusion and exclusion criteria from March 2015 to March 2018 in our hospital. The recovery of diseased vertebrae was assessed.

RESULTS

The cases were composed of 11 males and 4 females with a mean age of 74.3 ± 38.8 months. Nine cases presented with thoracic vertebral destruction, 6 cases with lumbar vertebral destruction. Under Garg's classification, 10, 3 and 2 cases were classified as Grade IIA, IB and IIB lesions, respectively. All patients had mild to moderate night-aggravated back pain and recovered at 1-week after surgery. Three patients had Frankel D neurologic symptoms and recovered at 1-week, 1-week and 4-weeks after surgery, respectively. Follow-up time after surgery ranged from 1.9 years to 4.5 years, with a mean of 2.9 years. The median vertebral height at 12 months after surgery was significantly higher than the preoperative height. Furthermore, the vertebral heights of all diseased vertebrae displayed significant recovery trends at 3, 6 and 12 months after surgical treatment. The percentages of vertebral height recovery to references at 12 months after surgery ranged from 34.7% to 92.5%, with an average of 71.2%.

CONCLUSIONS

In children with collapsed vertebral EGs, active surgical treatment is necessary to retain the ability to restore height and to reconstruct the spine stability.

Incidence, Clinical Features, and Outcomes of Langerhans Cell Histiocytosis in the United States

Langerhans cell histiocytosis (LCH) is a disorder with highly diverse clinical manifestations. We explored if age, sex, race, organ system involved, and therapy approaches determine patient survival in the era of modern treatments. LCH patient data reported to the Surveillance, Epidemiology, and End Results (SEER) program in 2010-2016 (n=1282; age: 0 to 100 y) was analyzed. Age-specific LCH incidence flattening to a low level suggests an age cutoff for pediatric patients of 20 years. The overall survival probability is lower for patients 21 to 100 years old ( P <0.0001), irrespective of sex and race. The commonest sites involved in the 0- to 20-year age group were bone, skin, and bone marrow; this shifted to lung, bone, and skin as the commonest disease sites in patients 21 to 100 years of age. The treatments applied differed between age groups, as younger versus older patients were more likely to receive chemotherapy-based treatment (48.4% vs. 17%; P <0.0001). There also was a trend toward nonwhite versus white patients being less likely to receive chemotherapy-based treatment (31.7% vs. 38.2%; P =0.067). Whereas there are treatment disparities related to LCH patient age and perhaps race, patient age is the strongest predictor of survival, with patients 21 to 100 years of age with lung, lymph node, skin, and bone marrow disease having the worst outcomes ( P <0.0001).

A case of adult multisystem Langerhans histiocytosis successfully treated by smoking cessation and radiotherapy for bone lesion

An adult patient was diagnosed with multisystem Langerhans cell histiocytosis with lung and bone lesions. Her lung lesions improved after smoking cessation. Radiotherapy was performed for the bone lesions. Follow‐up assessment at 2 years after diagnosis showed no recurrence. Our case shows that remission is possible even without systemic treatment.

Does Fractal Analysis Have a Role in Diagnosis of Langerhans Cell Histiocytosis?

PURPOSE

Langerhans cell histiocytosis (LCH) of the jaws is a rare disease and is often diagnosed at an advanced stage. This study aims to assess the trabecular pattern of jaws via fractal analysis (FA) on initial panoramic radiographs (OPG) of the patients with LCH to facilitate interpretation of the radiographic changes.

METHODS

A case-control study investigated LCH cases with jaw involvement retrieved from the databases of Istanbul and Kocaeli Universities between 2010 and 2021. Initial OPGs of LCH cases and OPGs of healthy sex- and age-matched controls were investigated with FA. All images were assessed using ImageJ software. On each OPG, a total of 6 regions of interest (ROIs) located on the mandible were investigated bilaterally. The independent variables were the trabecular patterns of jaws of LCH cases and their control matches. The outcome variables were the fractal dimension (FD) values obtained from the ROIs on OPGs. Data were analyzed using the Mann-Whitney U test and Student's t test.

RESULTS

Fifteen LCH-control pairs were investigated. In one ROI located in the supracortical area above the left mandibular angle, FD values of LCH cases (1.273 ± 112.8) were significantly lower than controls (1.308 ± 85.3; P < .05). Lower FD values were also calculated for some of the remaining ROIs, but there was no significant difference between groups (P > .05).

CONCLUSIONS

Regarding our results, FA was not a useful parameter to discern radiographical trabecular changes between LCH cases and controls. Multicenter studies with larger populations are needed to investigate the potential of FA in the identification of this rare disease.

Aggressive unifocal bone Langerhans cell histiocytosis with soft tissue extension both responsive to radiotherapy: a case report

BACKGROUND

Langerhans cell histiocytosis (LCH) is a rare haematological neoplasm characterized by the accumulation of CD1a⁺, CD207/Langerin⁺ histiocytes within inflammatory lesions. LCH can involve any organ, but osteolytic bone lesions are most often encountered. Unifocal bone lesions may regress spontaneously after a thick needle biopsy has been taken.

CASE PRESENTATION

In this case report, we describe the initial presentation of a single BRAF^V600E mutated osteolytic LCH lesion in the left proximal humerus of a 46-year-old previously healthy woman. Despite multiple surgical interventions, she unexpectedly experienced progressive disease manifestation with significant soft tissue extension to the surrounding musculature, subcutis and epidermis. Because the disease manifestation remained loco-regional, radiotherapy (RT) (total dose of 20 Gy in 10 fractions) was initiated.

CONCLUSION

The patient achieved a complete remission without any side effects. This case highlights that RT is a rational and relative mild local treatment option for patients with aggressive LCH affecting the bone and surrounding soft tissue.

[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.

Isolated Langerhans Cell Histiocytosis of the Vulva in a 28-Year-Old Lady: A Report of a Case and Brief Review of the Literature

Langerhans cell histiocytosis (LCH) is a rare, proliferative disorder of Langerhans' cells. The presentation can vary from single organ involvement to multisystem and disseminated in severe cases, affecting children more than adults. Isolated vulvar involvement of LCH in a 28-year-old woman has rarely been described and also there are limited data for diagnosis and treatment. Herein, we report the case of a 28-year-old woman with isolated vulvar LCH, misdiagnosed with herpes simplex infection, successfully treated with thalidomide.

International expert consensus recommendations for the diagnosis and treatment of Langerhans cell histiocytosis in adults

Langerhans cell histiocytosis (LCH) can affect children and adults with a wide variety of clinical manifestations, including unifocal, single-system multifocal, single-system pulmonary (smoking-associated), or multisystem disease. The existing paradigms in the management of LCH in adults are mostly derived from the pediatric literature. Over the last decade, the discovery of clonality and MAPK-ERK pathway mutations in most cases led to the recognition of LCH as a hematopoietic neoplasm, opening the doors for treatment with targeted therapies. These advances have necessitated an update of the existing recommendations for the diagnosis and treatment of LCH in adults. This document presents consensus recommendations that resulted from the discussions at the annual Histiocyte Society meeting in 2019, encompassing clinical features, classification, diagnostic criteria, treatment algorithm, and response assessment for adults with LCH. The recommendations favor the use of 18F-Fluorodeoxyglucose positron emission tomography-based imaging for staging and response assessment in the majority of cases. Most adults with unifocal disease may be cured by local therapies, while the first-line treatment for single-system pulmonary LCH remains smoking cessation. Among patients not amenable or unresponsive to these treatments and/or have multifocal and multisystem disease, systemic treatments are recommended. Preferred systemic treatments in adults with LCH include cladribine or cytarabine, with the emerging role of targeted (BRAF and MEK inhibitor) therapies. Despite documented responses to treatments, many patients struggle with a high symptom burden from pain, fatigue, and mood disorders that should be acknowledged and managed appropriately.

Clinical analysis for 15 patients with pulmonary Langerhans cell histiocytosis and literature review

OBJECTIVES

Pulmonary Langerhans cell histiocytosis (PLCH) is a clonal disease, characterized by proliferation of Langerhans cells that derived from bone marrow infiltrating the lungs and other organs. Due to the rarity of the disease, the current understanding of the disease is insufficient, often misdiagnosed or missed diagnosis. This study aims to raise clinicians' awareness for this disease via summarizing the clinical characteristics, imaging features, and treatment of PLCH.

METHODS

We retrospectively analyzed clinical and follow-up data of 15 hospitalized cases of PLCH from September 2012 to June 2021 in the Second Xiangya Hospital of Central South University.

RESULTS

The age of 15 patients (9 men and 6 women, with a sex ratio of 3 to 2) was 21-52 (median 33) years. Among them, 8 had a history of smoking and 5 suffered spontaneous pneumothorax during disease course. There were 3 patients with single system PLCH and 12 patients with multi-system PLCH, including 7 patients with pituitary involvement, 7 patients with lymph node involvement, 6 patients with bone involvement, 5 patients with liver involvement, 2 patients with skin involvement, 2 patients with thyroid involvement, and 1 patients with thymus involvement. The clinical manifestations were varied but non-specific. Respiratory symptoms mainly included dry cough, sputum expectoration, chest pain, etc. Constitutional symptoms included fever and weight loss. Patients with multi-system involvement experienced symptoms such as polyuria-polydipsia, bone pain, and skin rash. All patients were confirmed by pathology, including 6 by lung biopsy, 3 by bone biopsy, 2 by lymph node biopsy, and 4 by liver, skin, suprasternal fossa tumor, or pituitary stalk biopsy. The most common CT findings from this cohort of patients were nodules and/or cysts and nodular and cystic shadows were found in 7 patients. Three patients presented simple multiple cystic shadows, 3 patients presented multiple nodules, and 2 patients presented with single nodules and mass shadows. Pulmonary function tests were performed in 4 patients, ventilation dysfunction was showed in 2 patients at the first visit. Pulmonary diffusion function tests were performed in 4 patients and showed a decrease in 3 patients. Smoking cessation was recommended to PLCH patients with smoking history. Ten patients received chemotherapy while 2 patients received oral glucocorticoid therapy. Among the 11 patients with the long-term follow-up, 9 were in stable condition.

CONCLUSIONS

PLCH is a neoplastic disease closely related to smoking. The clinical manifestations and laboratory examination are not specific. Pneumothorax could be the first symptom which is very suggestive of the disease. Definitive diagnosis relies on histology. There is no unified treatment plan for PLCH, and individualized treatment should be carried out according to organ involvement. Early smoking cessation is essential. Chemotherapy is the main treatment for rapidly progressing PLCH involved multiple organs. All diagnosed patients can be considered for the detection of BRAFV600E gene and relevant targeted therapies have been implemented recently.

Adult Langerhans Cell Histiocytosis and the Skeleton

Langerhans cell histiocytosis (LCH) is a rare inflammatory neoplasia in which somatic mutations in components of the MAPK/ERK pathway have been identified. Osseous involvement is evident in approximately 80% of all patients and may present as a single osteolytic lesion, as a multi-ostotic single system disease or as part of multisystem disease. Both exogenous, such as treatment with glucocorticoids, and endogenous parameters, such as anterior pituitary hormone deficiencies and inflammatory cytokines, may severely affect bone metabolism in LCH. Computed tomography (CT) or magnetic resonance imaging (MRI) are usually required to precisely assess the degree of bone involvement; 18F-fluorodeoxyglucose (FDG) positron emission tomography-CT can both detect otherwise undetectable LCH lesions and differentiate metabolically active from inactive or resolved disease, while concomitantly being useful in the assessment of treatment response. Treatment of skeletal involvement may vary depending on location, extent, size, and symptoms of the disease from close observation and follow-up in unifocal single-system disease to chemotherapy and gene-targeted treatment in cases with multisystem involvement. In any case of osseous involvement, bisphosphonates might be considered as a treatment option especially if pain relief is urgently needed. Finally, a patient-specific approach is suggested to avoid unnecessary extensive surgical interventions and/or medical overtreatment.

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.

A CT Algorithm Can Elevate the Differential Diagnosis of Interstitial Lung Disease by Non-specialists to Equal That of Specialist Thoracic Radiologists

BACKGROUND

Diagnosis of diffuse parenchymal lung diseases (DPLD) on high resolution CT (HRCT) is difficult for non-expert radiologists due to varied presentation for any single disease and overlap in presentation between diseases.

RATIONALE AND OBJECTIVES

To evaluate whether a pattern-based training algorithm can improve the ability of non-experts to diagnosis of DPLD.

MATERIALS AND METHODS

Five experts (cardiothoracic-trained radiologists), and 25 non-experts (non-cardiothoracic-trained radiologists, radiology residents, and pulmonologists) were each assigned a semi-random subset of cases from a compiled database of DPLD HRCTs. Each reader was asked to create a top three differential for each case. The non-experts were then given a pattern-based training algorithm for identifying DPLDs. Following training, the non-experts were again asked to create a top three differential for each case that they had previously evaluated. Accuracy between groups was compared using Chi-Square analysis.

RESULTS

A total of 400 and 1450 studies were read by experts and non-experts, respectively. Experts correctly placed the diagnosis as the first item on the differential versus having the correct diagnosis as one of their top three diagnoses at an overall rate of 48 and 64.3%, respectively. Pre-training, non-experts achieved a correct diagnosis/top three of 32.5 and 49.7%, respectively. Post-training, non-experts demonstrated a correct diagnosis/top three of 41.2 and 65%, a statistically significant increase (p < 0.0001). In addition, post training, there was no difference between non-experts and experts in placing the correct diagnosis within their top three differential.

CONCLUSION

The diagnosis of DPLDs by HRCT imaging alone is relatively poor. However, use of a pattern-based teaching algorithm can improve non-expert interpretation and enable non-experts to include the correct diagnosis within their differential diagnoses at a rate comparable to expert cardiothoracic trained radiologists.

Waxing and Waning Neuroimaging Abnormalities in Langerhans Cell Histiocytosis

Langerhans cell histiocytosis (LCH) is a rare disease in adults characterized by proliferation of CD1a+/CD207+ and S100 myeloid dendritic cells, forming granulomas.1 An inflammatory exudate is often found with “bean-shaped” nucleated histiocytes. We report a patient with multisystem (liver, lung and brain) LCH in whom neuroimaging abnormalities accumulated and partially regressed prior to definitive treatment.

Multi-System Langerhans Cell Histiocytosis as a Mimic of IgG4-Related Disease: A Case Report and Literature Review

Langerhans cell histiocytosis (LCH) is a rare disease characterized by the clonal accumulation and/or proliferation of specific dendritic cells resembling normal epidermal Langerhans cells (LCs). Clinical manifestations are variable, depending on the affected tissues or organs, however, LCH with elevated serum IgG4 has not been reported. Herein, we reported a 26-year-old Chinese female multi-system LCH (MS-LCH) who first presented with central diabetes insipidus (CDI), accompanied by panhypopituitarism and hepatic dysfunction. Diagnostic investigations were strongly suspicious of IgG4-RD because of elevated serum IgG4 levels during the process. Furtherly, thyroid and lymph node involvement and biopsy led to the diagnosis of MS-LCH; the strongly positive staining of CD1a, S100, CD207 (langerin), and Ki67 was found. Moreover, after systemic treatment with five cycles of chemotherapy, many lesions were greatly improved. Since both LCH and IgG4-RD are orphan diseases that can affect any organ, the differential diagnosis is challenging, especially when LCH is associated with unexplained serum IgG4 elevation. In this article, the case of a young woman suffering from MS-LCH that affected organs including the pituitary, thyroid, lymph node, and liver was summarized, and relevant literature was reviewed to better equip the diagnosis and treatment in its early stages.

Multifocal, Multisystem Presentation of Adult-Onset Langerhans Cell Histiocytosis on 18F-Fluorodeoxyglucose Positron-Emission Tomography-Computed Tomography: A Rare Case Report

Langerhans cell histiocytosis (LCH), also known as histiocytosis X, is a rare systemic disorder arising from clonal proliferation of immature CD207-positive (langerin) myeloid dendritic cells (histiocytes) in the skin and visceral organs with a tendency to involve single or multiple organ systems with variable clinical course and prognosis. The incidence of LCH is very less in adult and occurs almost exclusively in children. Genital, perianal, and lung lesions are considered to be rare manifestations of adult LCH. We describe a case of 31-year-old, nonsmoker female who presented in February 2020 with itching and burning sensation in perianal and vulvar regions accompanied with multiple nonhealing ulcers and papillomatous lesions. These lesions gradually increased in size with no response to antibiotics and topical steroids. She was advised positron-emission tomography- computed tomography (PET-CT) scan for further evaluation. After PET-CT scan, her provisional diagnosis of multisystem, multifocal Langerhans cell histiocytosis with high-risk organ involvement was made. Both vulvar and perianal lesions were biopsied which was suggestive of Letterer-Siwe variant of LCH. The prognosis of this variant is very poor even with aggressive chemotherapy and 5-year survival rate of only 50%. Hence, it requires careful consideration during diagnosis and management.

Better vertebrae remodeling in pediatric spinal eosinophilic granuloma patients treated with kyphoplasty and short-term posterior instrumentation: A minimal two-year follow-up with historical controls

OBJECTIVE

To assess the validity and safety of kyphoplasty combined with short-term posterior instrumentation to treat children with vertebrae plana due to eosinophilic granuloma (EG).

PATIENTS AND METHODS

Clinical data of EG patients, who received kyphoplasty and short-term instrumentation from March 2019 to March 2020, were retrospectively reviewed. The recovery of diseased vertebrae was assessed and compared with historical case data.

RESULTS

Nine patients with EG had received kyphoplasty and short-term posterior instrumentation. The mean age at initial treatment was 66.7 months old (range, 28-132 months). The average number of follow-up months was 26.7. (range, 24-30 months).Four and 5 cases presented with thoracic and lumbar vertebral destruction, respectively. Under Garg's classification, 7 and 2 cases were classified as Grade IIA and IIB, respectively. The average diseased vertebral heights at 1-year and 2-year after surgery were significantly higher than the preoperative heights. The average percentages of diseased vertebral heights to references at 1-year and 2-year after surgery were 72.0% and 86.0%, respectively. The average percentage of diseased vertebral heights to the references at 2-year after surgery was significantly higher than that of the historical cases at the same time. No minor or major adverse events were observed.

CONCLUSIONS

Transpedicular balloon kyphoplasty for the direct restoration of vertebrae plana seems feasible and safe in combination with short-term posterior instrumentation. Better short-time vertebrae remodeling was observed 2 years after surgery. Active surgical treatment is suggested for children who have vertebrae plana as a result of EG in order to maintain the ability to recover vertebral height.

Pulmonary Langerhans cell histiocytosis and multiple system involvement: A case report

BACKGROUND

Pulmonary Langerhans cell histiocytosis (PLCH) is a relatively rare type of lung disease, common in middle-aged smoking men. It is characterized by proliferation and infiltration of Langerhans cells, and the formation of multiple parabronchial mesenchymal nodules in lung tissue, and may lead to organ dysfunction. There are no typical symptoms and signs, and it is easily misdiagnosed or missed, and therefore deserves clinical attention and further discussion.

CASE SUMMARY

We describe the case of a nonsmoking 46-year-old man with PLCH diagnosed based on clinical manifestations of fever and dry cough, with a history of hypothyroidism and diabetes insipidus for 9 years. Computed tomography (CT)- and CT-guided puncture examinations revealed no abnormalities, and he ultimately underwent thoracoscopic biopsy to confirm the diagnosis. The pathological diagnosis was PLCH. Thyroid function was maintained by medication. Pituitary magnetic resonance imaging showed that the pituitary stalk had become thinner.

CONCLUSION

LCH often involves multiple systems. Moreover, the pathogenesis is not clear, clinical manifestations lack specificity, and diagnosis requires special attention. Diagnosis of PLCH can significantly benefit from comprehensive multidisciplinary analysis.

Langerhans cell histiocytosis with lung involvement in isolation and multisystem disease: Staging, natural history, and comparative survival

Langerhans cell histiocytosis (LCH) is a histiocytic neoplasm that can involve the lungs as single system (LCH-SSL) or multisystem disease (LCH-MSL). The role of full-body radiographic staging to determine whether patients have LCH-SSL or LCH-MSL is unclear. Long-term outcomes of LCH-SSL versus LCH-MSL and multisystem without lung involvement (LCH-MSNL) are unknown. A retrospective study of adult LCH patients seen at our center from January 2000 to 2020 was performed. In Part 1, we addressed utility of whole-body staging imaging among those presenting with isolated pulmonary signs or symptoms. Staging was defined as fluorodeoxyglucose positron emission tomography-computed tomography (CT) or whole-body CT obtained within 3 months of diagnosis. In Part 2, we examined the frequency of developing extra-pulmonary disease over time and mortality in patients with LCH-SSL. In Part 3, we compared the overall survival of LCH-SSL, LCH-MSL, and LCH-MSNL. Part 1: 240 patients with LCH were identified. A total of 112 (47%) had pulmonary signs or symptoms at presentation. Thirty-four (30%) underwent radiographic staging and only one showed evidence of extra-pulmonary disease. Part 2: 108 (45%) were LCH-SSL. Median follow-up duration of 4.5 years (95% confidence interval [CI]: 2.9-6.0). None developed extra-pulmonary disease. Part 3: 5-year survival: 94% (95% CI: 84%-98%) for LCH-SSL, 78% (95% CI: 59%-90%) for LCH-MSL, and 75% (95% CI: 53%-89%) for LCH-MSNL. LCH patients presenting with isolated pulmonary signs or symptoms rarely have extra-pulmonary involvement at the time of diagnosis and generally do not develop extra-pulmonary progression. LCH-SSL has the best overall survival, while LCH-MSL and LCH-MSNL have similar clinical outcomes.

Histiocytic Neoplasms, Version 2.2021, NCCN Clinical Practice Guidelines in Oncology

Histiocytic neoplasms are rare hematologic disorders accounting for less than 1% of cancers of the soft tissue and lymph nodes. Clinical presentation and prognosis of these disorders can be highly variable, leading to challenges for diagnosis and optimal management of these patients. Treatment often consists of systemic therapy, and recent studies support use of targeted therapies for patients with these disorders. Observation ("watch and wait") may be sufficient for select patients with mild disease. These NCCN Guidelines for Histiocytic Neoplasms include recommendations for diagnosis and treatment of adults with the most common histiocytic disorders: Langerhans cell histiocytosis, Erdheim-Chester disease, and Rosai-Dorfman disease.

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.

Clinical features and treatment of Langerhans cell histiocytosis

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

Survivorship Issues in Adult Patients With Histiocytic Neoplasms

Adult-onset histiocytoses (AOH), primarily Rosai-Dorfman disease (RDD), Erdheim-Chester Disease (ECD), and adult Langerhans cell histiocytosis (ALCH), are a group of related histiocytic neoplastic disorders featuring multisystemic manifestations. The disorders are largely incurable, and are essentially chronic neoplastic diseases with a variable prognosis. Prompt diagnosis and treatment is important to prevent debilitating and even life-threatening complications. Survivorship issues abound in AOH, due to their multisystemic manifestations and the sometimes recalcitrant chronic inflammation, which can lead to other debilitating complications such as fatigue, weakness, and pain. Because these disorders are rare, few healthcare professionals are proficient in their management; therefore the aim of these guidelines is to offer guidance on how to manage patients, and how to create survivorship care plans through the efforts of an interdisciplinary team.

Hypophysitis: A comprehensive overview

Hypophysitis is defined as inflammation of the pituitary gland. It is a heterogeneous condition as it can originate from different parts of the pituitary gland, can be caused by different pathophysiological processes, and can be isolated or the manifestation of a underlying systemic disease. Hypophysitis usually presents with endocrine deficiencies, including diabetes insipidus, with varying patterns. A subset of patients presents with mass effects. The last decades major progress has been made in the understanding of this disease. New forms are now recognized, new diagnostics are being developed, and specific treatments are proposed. This review provides an overview of the current knowledge on hypophysitis using an aetiology-based approach and provides the clinician with a stepwise approach to the patient with (suspected) hypophysitis.

18F-FDG PET/MR Assessment of Pediatric Langerhans Cell Histiocytosis

Introduction

Langerhans cell histiocytosis (LCH) is a histiocytic proliferative disease without a well-understood etiology. The aim of our study is to summarize the imaging features of PET/MR in children with LCH and to explore its diagnostic role in LCH.

Methods

Retrospective analysis was performed of the pretreatment PET/MR imaging data of 15 children with LCH. Comparison of ADC values was done between lesions and normal tissues.

Results

Of the fifteen patients enrolled, five had single-organ or single-system involvement, and ten had multiple-system involvement. Nine patients had varying degrees of bone destruction and increased FDG uptake, whereas thickening and deviation of the pituitary stalk and disappearance of the normal high-signal intensity of T1WI in the neurohypophysis were observed in the pituitary gland in six of them. Splenomegaly with diffuse increased FDG uptake or a normal spleen with increased FDG uptake was found in four cases, liver in three, multiple lymph node enlargement in three, pulmonary lesions in three, and increased metabolism in medullary cavity in two cases. Additionally, two cases involved the skin. Hypermetabolic nodules were detected in muscle in one case, thyroid involvement in one case, and a mediastinal lesion in one case.

Conclusion

PET/MR can show well the distribution of the organs, systems, and lesions involved in LCH and is of considerable significance in the systemic evaluation of LCH.

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.