Langerhans cell histiocytosis: Current concepts and treatments. Cancer Treat Rev. 2010;36:354-359. [PMID: 20188480 DOI: 10.1016/j.ctrv.2010.02.012]

Langerhans cell histiocytosis involving the temporal bone with destruction and subsequent reossification of the bony labyrinth boundaries

PURPOSE

 With an incidence between 1-9/100 000 per year, Langerhans cell histiocytosis (LCH) is a rather rare disease from the hemato-oncologic disease spectrum (Hayes et al. 2009). The tumorlike disease with proliferation of histiocytic cells may manifest as localized to one organ or disseminated with infiltration of a wide variety of organs. Approximately 25-30 % of these cases show involvement of the temporal bone (Ni et al. 2017).

CASE DESCRIPTION

 With vertigo persisting for three years, chronic mastoiditis, and acute progressive hearing loss bilaterally (r > l) for three weeks, a 41-year-old woman presented at an emergency department. The DVT showed extensive bony destruction of large parts of the temporal bone on both sides, involving the vestibular organ, the cochlea, and the internal auditory canal. To confirm the suspicion of a systemic inflammatory process, a PE was performed from the mastoid with bioptic confirmation of an LCH. Systemic therapy was initiated. Post-therapeutic imaging showed almost complete remission with reossification of the preexisting defect zones and the internal auditory canal and labyrinth structures again showed bony margins. Clinically, there was an improvement of the vegetative symptoms with remaining bilateral sensorineural hearing loss.

DISCUSSION

 LCH of the temporal bone is a rare and often misdiagnosed disease due to its nonspecific clinical presentation. Awareness of temporal bone LCH and its occurrence in adults is essential for accurate and consistent diagnosis.

KEY POINTS

  · LCH is a rather rare disease from the hemato-oncological spectrum. · Affection of the temporal bone, especially such an extensive one (as in this case report), is rather atypical in adulthood. · Use of systemic therapy resulted in remission. · There was complete reossification of the osseous structures post-therapy. · A cochlear implant was able to be implanted to compensate for hearing loss.

Isolated skeletal Langerhans cell histiocytosis in adults: A case report

INTRODUCTION AND IMPORTANCE

LCH in adults is rarely encountered, with the preference in children and axial skeleton as predilection site. Limited understanding of adult LCH causes frequent misdiagnosis, as our experience in an adult case of LCH threw off our differential diagnosis.

CASE PRESENTATION

A 21-year-old male was referred to our hospital due to pain in his right shoulder. Plain radiograph and MRI showed a solitary well-marginated lytic lesion on the distal third of the clavicle. Together with a clear history and physical exam, the benign bone cyst was suspected and we performed an open biopsy simultaneously with curettage followed by internal fixation using a bone graft. Pathology and immunohistochemistry dismissed our suspicion and confirmed LCH as the main diagnosis. At six months post-surgery, no signs of recurrence were seen on the fixated site nor complained by the patient.

DISCUSSION

Diagnosing LCH involves considering imaging appearances and patient demographics as initial clues. However, confirming the diagnosis requires a biopsy with proven CD1 expression. Currently, the majority of studies recommend confirming the diagnosis before initiating therapy. This precaution is necessary due to the unclear pathophysiology of LCH, which complicates the implementation of specific therapies. Based on benign features of skeletal lesions found from imaging, invasive treatment before biopsy confirmation still gave a satisfactory outcome despite not being in line with the current recommendation.

CONCLUSION

Excisional biopsy and curettage in solitary LCH yield satisfactory outcomes. However, further studies are needed with larger sample sizes and interventional designs.

Potential indication of chemotherapy for hypodipsia and arginine vasopressin deficiency secondary to hypothalamic-pituitary Langerhans cell histiocytosis: a case report and literature review

Hypothalamic-pituitary Langerhans cell histiocytosis (HP-LCH) is often associated with arginine vasopressin deficiency (AVD). Patients with AVD caused by HP-LCH rarely develop an impaired osmotic threshold for thirst (OTT). Improvement in OTT among such patients has not been reported in the literature. To our knowledge, here we report the first case of AVD due to HP-LCH in which hypodipsia resolved during chemotherapy. A nine-year-old Japanese girl presented with polydipsia, polyuria, anorexia, and hypernatremia (149.8 mEq/L) and was diagnosed with AVD secondary to HP-LCH. Visual analog scale examination showed a reduced OTT following the water deprivation test. During chemotherapy for Langerhans cell histiocytosis (LCH), serum sodium concentrations became stable between 138.9 and 142.9 mEq/L under the replacement of desmopressin. Repeated visual analog scale examinations showed that she experienced a sense of thirst at a serum sodium concentration of 142.3-144.6 mEq/L, at which she did not experience any thirst prior to the initiation of chemotherapy. These data suggest that chemotherapy directly improved the OTT in our patient. Improved mechanical compression or infiltration of the hypothalamus related to OTT may lead to the recovery of the sense of thirst. This report highlights the potential role of chemotherapy for solitary HP-LCH in patients with hypodipsia and AVD.

Pulmonary Langerhans Cell Histiocytosis in an African Lion: A Rare Case Report

BACKGROUND

Feline pulmonary Langerhans cells histiocytosis (PLCH) is a rare disorder that results in progressive respiratory failure secondary to pulmonary parenchymal infiltration with Langerhans cells (LCs). A diagnosis of PLCH is proposed based on the clinical features and pathological findings and confirmed based on the infiltrating histiocytic cells. There are few documented cases of feline PLCH, and this case report of PLCH in an African Lion could present new information and aspects of this feline histiocytic disease.

CASE PRESENTATION

An African lion at Hohhot Zoo showing severe hyporexia and dyspnea with subsequent mental depression and emaciation died of exhaustion after a 35-day course of illness. Empirical treatment did not have a significant effect. An autopsy revealed that the lungs were enlarged and hardened due to infiltrative lesions, with many yellowish-white foci in all the lobes and sections. Furthermore, the kidneys were atrophied and had scattered grayish-white lesions on the surface. At the same time, congestion was widely distributed in various locations, including the liver, subcutaneous loose connective tissues, serosal surface and other tissues and organs. Histologically, proliferative histiocytic cells (PHCs) were scattered in the alveolar cavities, bronchioles and submucosa of bronchioles, with evident cellular and nuclear pleomorphism, and thus the alveolar septa were obliterated. The histopathological changes in other organs included chronic sclerosing glomerulonephritis, proliferated Kupffer cells in the liver, adrenal edema and interstitial connective tissue hyperplasia, as well as atrophy of the small intestines and spleen. Furthermore, immunohistochemical analysis results were strongly positive for CD1a, vimentin, S100 and E-cadherin in the membrane or cytoplasm of PHCs, supporting an LC phenotype.

CONCLUSIONS

Here, we present a rare pulmonary Langerhans cell histiocytosis case in an African lion.

Langerhans cell histiocytosis of the skull in 23 children

OBJECTIVE

To explore the clinical features, diagnosis, treatment and prognosis of Langerhans cell histiocytosis (LCH) of the skull in children.

METHODS

This study retrospectively summarized the clinical manifestations, treatment methods and follow-up status of children with skull LCH who were admitted to the Department of Neurosurgery of Shanghai Children's Hospital from January 2014 to June 2021.

RESULTS

A total of 23 patients confirmed by histology as LCH received hospitalization treatment, including 14 males and 9 females, aged (5.76 ± 3.86) years old. The clinical manifestations were mostly incidentally discovered head masses that gradually enlarged (19 cases, 82.61%). Only 2 cases are affected by multiple systems, while the rest are affected by single systems. 9 patients were involved in multiple skull lesions, and 14 patients had local skull lesions. All patients underwent surgical intervention, with 17 patients undergoing total resection and 6 patients undergoing biopsy. 21 patients received chemotherapy after surgery. The median follow-up was 2.46 years (range 0.33-6.83 years). 21 patients had their symptoms and signs under control or even resolved, and 2 patients experienced recurrence during follow-up. The overall control rate reached 91.30%.

CONCLUSION

Personalized treatment plans according to different clinical types. Regular outpatient follow-up is crucial to monitor disease recurrence and late effects.

Pediatric pulmonary multisystem langerhans cell histiocytosis: does lung lesion severity affect the outcome?

BACKGROUND

The pediatric pulmonary multisystem Langerhans cell histiocytosis (PPM LCH) is associated with either low risk or high risk organ(s). The nodulo-cystic lung lesions although pathognomonic, yet are very variable in severity and remain a source of controversy in certifying pulmonary LCH diagnosis. The study aimed to examine the prognostic value of clinical respiratory manifestations and radiological lung lesions severity. This is through associating a CT chest triad of bilateral, extensive and diffuse lesions. It is a retrospective study of 350 LCH patients who received systemic treatment at Children's Cancer Hospital Egypt during the period from 2007 to 2020.

RESULTS

Sixty-seven patients (67/350-19.1%) had PPM LCH at presentation. Severe lung lesions were present in 24 of them. The median follow-up period was 61 months (IQR: 3.4-8.3). The 5-year overall survival (OS) and event free survival (EFS) was 89% and 56.6% respectively. The EFS, for severe radiological lesions triad was 38% ± 20.7 versus 66% ± 16.2 for non-severe lesions triad p 0.002, while for presence of chest X-ray changes 27% ± 22.344 versus absence of chest X ray changes 66% ± 14.7 p 0.001, for clinical respiratory manifestations 13% ± 13.9 versus none 62% ± 22.9 p < 0.001, for RO- with severe lung lesions 47% ± 30.4 versus RO- without severe lung lesions 69% ± 5.9 p 0.04. There was a tendency for the independent prognostic impact of severe lung involvement; aHR = 1.7 (95% CI 0.92-3.13, p = 0.09).

CONCLUSION

Although the lung is a low -risk organ per se in LCH, our study demonstrates a non negligeable prognostic impact of severe lung involvement in the risk stratification of pediatric LCH. This warrants further study and external validation.

Vertebra Plana: A Narrative Clinical and Imaging Overview among Possible Differential Diagnoses

Vertebra plana is a rare radiologic condition characterized by a uniform loss of height of a vertebral body that represents a diagnostic challenge for surgeons. The purpose of this study was to review all possible differential diagnoses that may present with a vertebra plana (VP) described in the current literature. For that purpose, we performed a narrative literature review in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, analyzing 602 articles. Patient demographics, clinical presentation, imaging characteristics and diagnoses were investigated. VP is not a pathognomonic feature of Langerhans cell histiocytosis, but other oncologic and non-oncologic conditions should be considered. The list of differential diagnoses, based on our literature review, can be recalled with the mnemonic HEIGHT OF HOMO: H-Histiocytosis; E-Ewing's sarcoma; I-Infection; G-Giant cell tumor; H-Hematologic neoplasms; T-Tuberculosis; O-Osteogenesis imperfecta; F-Fracture; H-Hemangioma; O-Osteoblastoma; M-Metastasis; O-Osteomyelitis, chronic.

Primary Langerhans cell sarcoma in the urinary bladder: Case report and literature review

Langerhans cell sarcoma (LCS) is a rare malignancy of dendritic cells and usually results in a poor oncological outcome. Thus, LCS is usually given a positive administration. Herein, we presented the first case of primary LCS in the urinary bladder staged T1N0M0 and treated by TURBT and short-term local chemotherapy. Our experience in this unique case may suggest that LCS in the urinary bladder with a non-muscle-invasive stage may be managed according to the treatment model of non-muscle-invasive urothelial carcinoma of the urinary bladder.

Adult-onset Langerhans cell histiocytosis – A Trojan horse of oral cavity: A case report with rare clinical presentation

Langerhans cell histiocytosis (LCH), earlier recognised as histiocytosis X, is a rare haematological illness involving infants and young children. LCH is caused by unrestrained stimulation and proliferation of usual antigen presenting cells, Langerhans cells (LCs) and the disease demonstrates extensive clinical and radiographic features involving multiple sites. Since the incidence is relatively low limited data is available regarding the epidemiology of LCH, with approximation of 2-5 cases per million populations per year. LCH has male predilection with jaws involved in 10-20% cases and only 1% of the cases affecting maxilla, masquerading as periodontal or periapical pathology. We report a case of 48-year-old female with LCH involving posterior maxilla. This is a unique presentation corresponding to age, gender, location and severity. Dental clinicians should be aware of this and consider it to be a part of their differential diagnosis pertaining to unresolved periodontal pathology as it mimics clinically and radiographically.

Resolution and Re-ossification of Orbital Wall Langerhans Cell Histiocytosis Following Stereotactic Needle Biopsy

Introduction Langerhans cell histiocytosis (LCH) is a rare disease that encompasses a spectrum of clinical syndromes. It is characterized by the proliferation and infiltration of white blood cells into organs or organ systems. Reports of management of these lesions have included biopsy, resection, curettage, radiation and/or chemotherapy. Case Presentation A 40-year-old man presented with a history of right proptosis and retro-orbital pain and was found to have a lytic mass involving the greater wing of the sphenoid extending into the right orbit. A stereotactic needle biopsy using neuronavigation demonstrated this to be LCH. After no further treatment, the mass spontaneously resolved, with virtual normalization of the orbital MRI at 10 months following the needle biopsy. The bony defect of the temporal bone caused by the mass also re-ossified following the needle biopsy. Discussion This report highlights the potential for an isolated LCH lesion to regress after simple needle biopsy, an outcome only rarely reported previously. Thus, expectant management of such lesions following biopsy or initial debridement should be considered prior to proceeding with additional treatment.

Langerhans cell histiocytosis of the head and neck in the pediatric population in a tertiary center: Clinical presentation, classification and treatment

INTRODUCTION

Langerhans cell histiocytosis (LCH) is a rare disease of unknown etiology with a heterogeneous and unspecific clinical presentation. Any organ or system may be involved but the most frequent is the skeleton. The diagnostic gold standard is done through histopathology combined with immunohistochemistry in the correct clinical setting. Treatment is still controversial. The objective of this study is to present a series of pediatric patients in order to contribute to the diagnosis and treatment of LCH.

MATERIAL AND METHODS

A longitudinal, descriptive and retrospective study was done in 20 pediatric patients histologically diagnosed of LCH int the last 10 years, in a tertiary center. A review of the medical history was done and data collection included: epidemiological data, clinical manifestations and classification, lesion characteristics, treatment employed, follow-up and evolution.

RESULTS

The mean age presentation was 6.5 years (2-12). The most frequent disease presentation was a palpable skull tumor followed by headache. Other otorhinolaryngologic presenting symptoms were bloody otorrhea and post auricular swelling. Single-systems LCH with skull tumors was the most frequent classification. Treatment options (surgery, chemotherapy and corticosteroid infiltration) were indicated according to disease classification.

CONCLUSION

LCH should be suspected in pediatric patients with a palpable cranial vault tumor, as well as in patients with chronic otorrhea with granulation tissue at the external ear canal. Management of LCH fundamentally includes chemotherapy and surgery, or the combination of both. High-risk organs lesions, including temporal bone lesions, and multi-system LCH are predictors of recurrence and should have a long-term follow-up.

Liver transplantation in a child with liver cirrhosis caused by langerhans cell histiocytosis: a case report

Background

Langerhans cell histiocytosis (LCH) is a rare condition that has a variety of clinical manifestations. But LCH in children localized only in the hepatobiliary system is unusual.

Case presentation.

Here we reported a rare case of a 2-year-old boy who was serendipitously found to have elevated liver enzymes while undergoing treatment of a perianal abscess. After a period of earlier conservative treatment in another hospital, the perianal abscess had resolved but the levels of liver enzymes were still rising slowly. The child was then referred to our institution for a definitive diagnosis. After laboratory tests, imaging and pathological examinations, a diagnosis of liver cirrhosis and sclerosing cholangitis was established, although the cause was unclear. Subsequently, living-donor liver transplantation was performed due to deterioration in liver function. Following successful liver transplantation, a diagnosis of LCH localized only within the hepatobiliary system was finally confirmed, based on additional pathological and imaging investigation. Additionally, the BRAF V600E mutation in this patient was also confirmed. The child has now recovered without evidence of LCH recurrence.

Conclusions

LCH localized only within the hepatobiliary system is unusual. The presence of unexplainable sclerosing cholangitis and liver cirrhosis in any child should raise the suspicion of LCH.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-021-03090-4.

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.

Eruptive agminated nevi in a successfully treated Langerhans cell histiocytosis patient

A 7-year-old girl with a history of Langerhans cell histiocytosis (LCH), in remission, presented with the sudden appearance of multiple, agminated nevi. Skin biopsy revealed a benign junctional nevus, without recurrence of LCH. Subsequent immunohistochemical testing of both the skin and iliac wing biopsies demonstrated a BRAF V600E mutation. MAPK pathway mutations have been implicated in both LCH and nevogenesis.

Three decades of progress from surgery to medical therapy for isolated neuroaxis BRAF V600E–positive Langerhans cell histiocytosis management: illustrative case

BACKGROUND

“Langerhans cell histiocytosis” (LCH) is a term that encompasses single-system or multisystem disorders traditionally characterized by a proliferation of clonal CD1a+/CD207+ myeloid-derived histiocytes. In most cases of LCH, mitogen-activated protein kinase (MAPK) pathway somatic mutations lead to near universal upregulation of phosphorylated extracellular signal-regulated kinase expression. The clinical manifestations of LCH are numerous, but bone involvement is common. Intracranial lesions, especially as isolated manifestations, are rare.

OBSERVATIONS

The authors presented the case of a long-term survivor of exclusive intracranial LCH that manifested with isolated craniofacial bone and intraparenchymal central nervous system recurrences, which were managed with 3 decades of multimodal therapy. The patient was initially diagnosed with LCH at age 2 years, and the authors documented the manifestations of disease and treatment for 36 years. Most of the patient’s treatment course occurred before the discovery of BRAF V600E. Treatments initially consisted of chemotherapy, radiosurgery, and open resections for granulomatous LCH lesions. Into young adulthood, the patient had a minimal disease burden but still required additional radiosurgical procedures and open resections.

LESSONS

Surgical treatments alleviated the patient’s immediate symptoms and allowed for tumor burden control. However, surgical interventions did not cure the underlying, aggressive disease. In the current era, access to systemic MAPK inhibitor therapy for histiocytic lesions may offer improved outcomes.

Periodontal manifestations of Langerhans cell histiocytosis: a systematic review

Objectives

To explore the evidence of periodontal manifestations and treatment modalities in patients with Langerhans cell histiocytosis (LCH).

Material and methods

A systematic literature search was performed and the criteria for PRISMA and risk of bias assessment were applied. Human clinical studies (≥10 patients) presenting patients with LCH and periodontal findings were considered for inclusion.

Results

From 298 titles identified, six case series with a total of 1278 patients suffering from LCH were included. In these studies, oral symptoms were reported in a frequency ranging from 10 to 100%. Overall, in 216 patients (17%), oral symptoms were observed. Out of these patients, 49–100% demonstrated periodontal symptoms. The most common oral findings were pain, swelling, tooth loss/mobility, and bone lesions. Specific periodontal findings comprised varying frequencies of gingival ulcerations, increased pocket depths, and gingival bleeding. Treatment measures constituted of surgical curettage of bone lesions, soft tissue excision and/or tooth extractions, radiotherapy, systemic chemotherapy, or a combination of these approaches. Healing without recurrence of oral lesions was reported in most of the cases.

Conclusions

The available evidence on periodontal manifestations in LCH patients is heterogeneous. Several oral and periodontal findings were reported and may occur as initial symptoms and/or at later stages of the disease.

Clinical relevance

The dentist should be aware of possible oral involvement of systemic diseases such as LCH, and these manifestations may mimic periodontal disease.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00784-021-03873-0.

Surgical Occlusion of Leaking Bronchus by a Serratus Anterior Flap in a Child with Langerhans Cell Histiocytosis

Langerhans cell histiocytosis is an uncommon disease of childhood. Intrathoracic transposition flaps have been described for a management of number of conditions. We discuss our experience of the use of serratus anterior flap for the obliteration of a pulmonary bulla with a communicating airway, in a 1½-year-old pediatric patient with multisystem Langerhans cell histiocytosis who presented with recurrent pneumothorax with empyema due to rupture of bullae.

Langerhans Cell Histiocytosis with Uncommon Liver Involvement: A Case Report

Patient: Female, 60-year-old

Final Diagnosis: Langerhans cell histiocytosis

Symptoms: Fatigue • weight loss

Medication: —

Clinical Procedure: —

Specialty: Radiology

Egyptian experience in Langerhans cells histiocytosis: frequent multisystem affection and reactivation rates

Background: Histiocytoses are unique disorders; their clinical presentations vary from self-healing lesions to life-threatening disseminated disease. Objectives: We aimed to evaluate the different clinical presentations, frequency of reactivations, and treatment outcome of Langerhans cell histiocytosis among Egyptian children. Methods: we restrospectively analyzed the data of 37 Langerhans cell histiocytosis patients (LCH) registered at Ain Shams University Children's Hospital for clinicopathological features, treatment modalities and their outcomes. Results: Twenty seven (73%) of the studied patients with LCH had multisystem disease (MS), 24 (88.9%) of them had risk organ involvement (MS RO+) and only 3 without risk organ (MS RO-). Most of the patients received LCH III protocols. Eleven patients (29.7%) had reactivations with median time till reactivation of 17 months (IQR 5-23).Reactivation rates were 40% and 50% in patients with no evidence of active disease (NAD) and those with active disease better (AD better) at week 6 evaluation respectively (p = 0.71).We report 9 deaths (all had MS RO+, two died after reactivation and 7 had progressive disease. The 5 years EFS and OS were 49.4% and 81.2% respectively. Risk stratification did not significantly affect the EFS or OS (p = 0.64 and p = 0.5 respectively). Conclusion: A high reactivation rate was encountered in children with LCH and MS-RO + irrespective of 6 weeks response to induction therapy. A high mortality in patients with progressive disease necessitates a possible earlier aggressive salvage in such group.

Langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH) is caused by clonal expansion of myeloid precursors that differentiate into CD1a+/CD207+ cells in lesions that leads to a spectrum of organ involvement and dysfunction. The pathogenic cells are defined by constitutive activation of the MAPK signaling pathway. Treatment of LCH is risk-adapted: patients with single lesions may respond well to local treatment, whereas patients with multisystem disease require systemic therapy. Although survival rates 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 is yet to be established. Treatment failure is associated with increased risks for death and long-term morbidity, including LCH-associated neurodegeneration. Early case series report promising clinical responses in patients with relapsed and refractory LCH treated with BRAF or MEK inhibitors, although potential for this strategy to achieve cure remains uncertain.

Langerhans Cell Histiocytosis of the Temporal Bone

Background: Langerhans cell histiocytosis (LCH) of the temporal bone is an uncommon disease that primarily affects the pediatric population; fewer than 40 adult cases have been reported in the literature. We present a rare case of LCH of the temporal bone in an adult patient and describe its clinical presentation, histopathologic findings, and management.

Case Report: A 21-year-old male presented to the emergency department with progressively worsening right-sided ear pain refractory to outpatient oral antibiotics. Physical examination revealed mastoid tenderness and decreased right-sided hearing. Computed tomography (CT) scan suggested coalescent mastoiditis; the patient responded to inpatient antibiotics and was discharged. He returned 9 days later with persistent symptoms. Repeat CT scan revealed an osteolytic lesion on the temporal bone, and the patient was indicated for surgery. Intraoperative histology was consistent with LCH. Subsequent surveillance magnetic resonance imaging (MRI) suggested persistence of disease, and the patient responded to a course of radiation. Three months following radiotherapy, surveillance MRI and positron emission tomography scans revealed no evidence of recurrent disease.

Conclusion: Diagnosis of LCH of the temporal bone is frequently delayed because of misdiagnosis of more common otologic diseases, including otitis media, otitis externa, and mastoiditis. The clinician's index of suspicion for LCH should be high if imaging reveals an osteolytic defect of the temporal bone; confirmation is via immunohistostaining of biopsy samples. The majority of cases respond to surgery, radiation, chemotherapy, or combination therapy, but delays in diagnosis and treatment may increase morbidity. Increased physician awareness of LCH of the temporal bone, particularly among adults, may help to improve patient outcomes.

Congenital Langerhans cell histiocytosis

Langerhans cell histiocytosis is a rare pathology with different clinical manifestations in the neonatal period ranging from isolated bone lesions to systemic compromise. We report a case of Langerhans cell histiocytosis including a literature review focused on the clinical manifestations, diagnosis, and treatment. A one-month-old patient was brought to medical consultation with lymphadenopathy and skin lesions, which were initially managed as an infectious pathology. The disease continued its progression without improvement with the treatment until the patient died due to respiratory failure. The lymph node and skin biopsies revealed infiltration of atypical cells with positive immunohistochemistry for S100, CD1, and CD68 confirming Langerhans cell histiocytosis. This disorder represents a great challenge and, therefore, it is important to alert and sensitize medical teams about it for timely diagnosis and management.

Regulatory T-cell expansion in oral and maxillofacial Langerhans cell histiocytosis

OBJECTIVE

Langerhans cell histiocytosis (LCH) is a rare myeloid-origin neoplasm characterized by the expansion and dissemination of CD1 a+/CD207+ dendritic cells (LCH cells), but the rarity of its occurrence has long impeded progress in understanding its pathology. We focus on the potentially important role that regulatory T cells (T-reg) play in the oral and maxillofacial LCH tumor microenvironment (TME).

STUDY DESIGN

Nine cases of oral and maxillofacial LCH, diagnosed from 2009 to 2019, were collected retrospectively from the affiliated hospitals of Southern Medical University. Immunohistochemistry was conducted characterizing T cells and T-reg phenotype. Data were evaluated by 1-sample Wilcoxon's test.

RESULTS

Significantly increased frequency and abnormal distributions of T-reg were identified in all the LCH lesion sections. Proliferating T-reg account for a mean average of 11.5% of the total T-cell subsets, with significant difference (Wilcoxon's test; P < .05).

CONCLUSIONS

T-reg expansion in the localized inflammatory TME leads to a failure of immune regulation by suppressing antitumor response, which can be a latent and significant factor contributing to LCH progression. However, T-reg may also acquire the capability for aiding in initiating T-cell responses under the "cytokine storm" at the beginning of LCH onset. T-reg might contribute to the augmentation of tissue repair by transforming growth factor-β (TGF-β), explaining the self-limiting character of LCH.

Skeletal involvement in children with Langerhans cell histiocytosis: healing, complications, and functional outcome

Introduction: Skeletal involvement in children with Langerhans cell histiocytosis (LCH) is a common feature of the disease. Several options for the treatment of these skeletal lesions have been reported. We describe our experience in the treatment of skeletal involvement of LCH in this retrospective case series study, entailing anatomic distribution, pattern of healing, skeletal deformities, and functional outcome of skeletal LCH. Methods: A retrospective analysis was conducted for patients diagnosed with LCH and having skeletal lesions in the period between 2007 and 2015. Out of a total of 229 cases, 191 (83.4%) had skeletal involvement. Bone healing was divided into partial and complete based on the size of lesion and cortical changes in plain radiograph. Skeletal deformities were serially measured. Time to pain control, resumption of weight bearing, and the final functional status of the patient were reviewed. Results: The mean age at presentation was 4.4 years (3 m–14.8 y) and the mean follow-up period was 53.3 months (0.2–120.7). After screening of skeletal and extra-skeletal lesions, 59 patients (31%) had M-S (Multisystem) LCH and 132 (69%) had S-S (Single system) LCH. Unifocal bone lesions were found in 81 (42.5%) patients, and multifocal bone lesions in 110 patients (57.5%). Single or multiple bone lesions were found in the craniofacial bones in 152 patients (79.5%), femur in 19 patients, (10%), ribs in 18 patients (9.4%), spine in 15 patients (8.1%), pelvis in 14 patients (7.3%), scapula in 8 patients (4.1%), humerus in 6 (3.1%), clavicle in 6 patients (3.1%), tibia in 3 patients (1.5%), radius in 3 patients (1.5%), and the ulna in 2 patients (1%) patients. No lesions were found in the fibula, hand, or foot. Out of all skeletal lesions, 179 (93.7%) patients were treated either medically or conservatively and 12 patients (6.2%) were treated surgically. The mean time to complete healing was 5.2 months (2–12). Skeletal complications included: pathologic fractures (9 vertebra plana, 5 long bone, 1 iliac bone), deformities (9 thoracolumbar kyphosis, 2 cervical spine subluxations, 2 coxa vara deformity of the proximal femur and one flattening of iliac bone). Conclusion: Non-operative treatment can lead to adequate bone healing in few months period. Partial or complete remodeling of bone deformities can be observed without surgical correction. However, surgical intervention might be indicated when cervical spine affection may lead to instability and subsequent neurological affection. Functional impairment is rarely caused by skeletal lesions in LCH.

Altered cerebral perfusion in children with Langerhans cell histiocytosis after chemotherapy

BACKGROUND AND PURPOSE

Children with Langerhans cell histiocytosis (LCH) may develop a wide array of neurological symptoms, but associated cerebral physiologic changes are poorly understood. We examined cerebral hemodynamic properties of pediatric LCH using arterial spin-labeling (ASL) perfusion magnetic resonance imaging (MRI).

MATERIALS AND METHODS

A retrospective study was performed in 23 children with biopsy-proven LCH. Analysis was performed on routine brain MRI obtained before or after therapy. Region of interest (ROI) methodology was used to determine ASL cerebral blood flow (CBF) (mL/100 g/min) in the following bilateral regions: angular gyrus, anterior prefrontal cortex, orbitofrontal cortex, dorsal anterior cingulate cortex, and hippocampus. Quantile (median) regression was performed for each ROI location. CBF patterns were compared between pre- and posttreatment LCH patients as well as with age-matched healthy controls.

RESULTS

Significantly reduced CBF was seen in posttreatment children with LCH compared to age-matched controls in angular gyrus (P = .046), anterior prefrontal cortex (P = .039), and dorsal anterior cingulate cortex (P = .023). Further analysis revealed dominant perfusion abnormalities in the right hemisphere. No significant perfusion differences were observed in the hippocampus or orbitofrontal cortex.

CONCLUSION

Perfusion in specific cerebral regions may be consistently reduced in children with LCH, and may represent effects of underlying disease physiology and/or sequelae of chemotherapy. Studies that combine a formal cognitive assessment and hemodynamic data may further provide insight into perfusion deficits associated with the disease and the potential neurotoxic effects in children treated by chemotherapy.

Pancreatic Langerhans cell histiocytosis in a cat

In contrast to pulmonary Langerhans cell histiocytosis (LCH), which is a proliferative disorder of Langerhans cells that affects the lungs and other organs of cats, LCH involving a single organ system has not been documented in cats, to our knowledge. Herein we describe a case of pancreatic LCH in a 9-y-old castrated male Domestic Shorthaired cat that was evaluated for possible renal transplantation. The cat was hypoglycemic, hyperinsulinemic, and azotemic. Ultrasound examination revealed a diffusely enlarged, normoechoic pancreas. The cat was euthanized because of severe renal azotemia and the possibility of pancreatic neoplasia. Grossly, the pancreas was enlarged, and both kidneys were pale white, firm, and had irregular capsular surfaces. Histologically, the pancreas was expanded with interlobular, intraparenchymal, and ductal clusters of round-to-polygonal cells admixed with fibrous connective tissue and scattered lymphocytes. Infiltrating cells had a moderate amount of eosinophilic cytoplasm, round-to-indented nuclei with finely stippled chromatin and 1 or 2 nucleoli, and were strongly immunoreactive for CD18, ionized calcium-binding adapter molecule 1, and e-cadherin. The morphologic and immunohistochemical features of the pancreatic changes were consistent with single-system LCH.

Thoracic spine Langerhans cell histiocytosis in a child with achondroplasia

Multifocal bone Langerhans cell histiocytosis (LCH) is usually treated with prednisolone and vinblastine. We present a case conservatively treated with indomethacin with good clinical and radiological response. A 7-year-old achondroplastic boy presented with worsening thoracic back pain and leg weakness. An admission MRI spine showed a pathological T1 vertebrae fracture with posterior soft tissue extension compressing and distorting the spinal cord. A CT guided biopsy revealed an LCH. Steroids were avoided to reduce osteopenia risk and further vertebral fragility. Considering the risk of a thoracic surgical approach in a child with this background, he was managed conservatively with indomethacin and a Sternal Occipital Mandibular Immobilizer (SOMI) Brace. Pain resolved completely within 6 months and the brace was discontinued. Serial follow-up scans showed progressive resolution of the pathological T1 fracture and complete resolution of the spinal cord compression.

[Langerhans cell histiocytosis involving the oral and maxillofacial region: an analysis of 12 cases]

OBJECTIVE

To study the clinical features of Langerhans cell histiocytosis (LCH) involving the oral and maxillofacial region in children.

METHODS

A retrospective analysis was performed for the clinical data of 12 children with LCH involving the oral and maxillofacial region who were hospitalized and treated from September 2012 to September 2017, including clinical manifestations, pathological features, treatment and prognosis.

RESULTS

Of the 12 children, 8 (67%) had multiple system involvement and 7 (58%) had the involvement of organs at risk. Bone was the most common affected site (11 children, 92%), among whom 7 children had the involvement of the mandible. Oral soft tissue involvement manifested as gingival ulcer or hyperplasia in 4 children, loose teeth in 5 children, oral mucosal lesions in 2 children, and nodular lesions in 1 child. Pathological examination showed positive CDla in 11 children and positive CD207, CD68, S-100, and LCA in 12 children. Surgery combined with chemotherapy was the major treatment method, and surgical resection alone was performed for focal lesions. After treatment, 11 children were cured or improved and 1 gave up treatment and was lost to follow-up. No recurrence was observed.

CONCLUSIONS

LCH children with oral and maxillofacial involvement often have the involvement of multiple systems and organs at risk, with the mandible as the most common affected site. These children may also have the involvement of gingiva, oral mucosa and teeth. Surgery combined with chemotherapy is the major treatment method, and the patients generally have a good prognosis without recurrence.

Secondary aneurysmal bone cyst in Langerhans cell histiocytosis: Case report, literature review

Langerhans cell histiocytosis (LCH) is a rare disease of the myeloid precursor cells, it predominantly occurs in the skull and long bones as unifocal bone lesions. Aneurysmal bone cysts (ABC) are benign, expansive and lytic bone. Reports of secondary ABC occurring in LCH are rare, having only been reported twice in the skull. Here, we report the first case of LCH masquerading as ABC in a 14-month-old female child who presented with a rapidly growing mass in her left femur. The lesion had typical radiological features of ABC, and only histological examination revealed the presence of cells suggestive of LCH.

Adult Langerhans' cell histiocytosis with multisystem involvement: A case report

RATIONALE

Langerhans' cell histiocytosis (LCH), also called histiocytosis X, is an uncommon disorder manifesting in a variety of ways. Although LCH can involve various organs including bone, skin, and lymph nodes, multisystem involvement of LCH is rare in adults.

PATIENT CONCERNS

A 31-year-old woman first presented to our hospital with left leg pain. She had a history of a 20-kg weight gain over three months.

DIAGNOSES

X-ray, magnetic resonance imaging (MRI), computed tomography (CT), and bone scan images revealed enhancing lesions in the left femur and right temporal bone, multiple cystic lesions in the lung, enhancing mass in the pituitary stalk, and fat density lesions in the liver. The patient underwent excisional biopsy for the femoral lesion and histologic examination confirmed the diagnosis of LCH.

INTERVENTIONS

Excisional biopsy was performed for the bony lesion in the left femur. She received chemotherapy with vinblastine and prednisolone.

OUTCOMES

The patient expired after 21 months from initial admission following recurrent episodes of pneumothorax, pneumonia, and sepsis.

LESSONS

Our case showed LCH involvement in bone, lung, central nervous system (CNS), and liver. Although it is occasionally difficult to discriminate LCH from other disorders, systemic evaluation might be helpful for differential diagnosis. Familiarity with the various multisystemic involvements of LCH on imaging is vital for diagnosing and managing patients in daily practice.

Selected Giant Cell Rich Lesions of the Temporal Bone

Giant cell rich lesions of the temporal bone encompass a wide spectrum of disease that includes infectious, reactive, and neoplastic processes. When dealing with any lesion that can potentially involve bone, it is important to understand both the clinical presentation and to correlate the histologic findings with the radiologic imaging. This review discusses the clinical, the pathologic features including the differential diagnosis, and the treatment of some of the more commonly encountered giant cell rich entities in this region.

Bone metabolism in Langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH) is a rare disease of not well-defined etiology that involves immune cell activation and frequently affects the skeleton. Bone involvement in LCH usually presents in the form of osteolytic lesions along with low bone mineral density. Various molecules involved in bone metabolism are implicated in the pathogenesis of LCH or may be affected during the course of the disease, including interleukins (ILs), tumor necrosis factor α, receptor activator of NF-κB (RANK) and its soluble ligand RANKL, osteoprotegerin (OPG), periostin and sclerostin. Among them IL-17A, periostin and RANKL have been proposed as potential serum biomarkers for LCH, particularly as the interaction between RANK, RANKL and OPG not only regulates bone homeostasis through its effects on the osteoclasts but also affects the activation and survival of immune cells. Significant changes in circulating and lesional RANKL levels have been observed in LCH patients irrespective of bone involvement. Standard LCH management includes local or systematic administration of corticosteroids and chemotherapy. Given the implication of RANK, RANKL and OPG in the pathogenesis of the disease and the osteolytic nature of bone lesions, agents aiming at inhibiting the RANKL pathway and/or osteoclastic activation, such as bisphosphonates and denosumab, may have a role in the therapeutic approach of LCH although further clinical investigation is warranted.

Langerhans Cell Histiocytosis: A Case Report with Unusual Cutaneous Manifestation

Langerhans cell histiocytosis (LCH) is characterized by idiopathic monoclonal infiltration of Langerhans cells in different organs such as the skeleton, skin, pituitary gland, liver, spleen, lungs, and the hematopoietic system. Skin lesions are common in LCH and affect about 40% of cases. It is reported that skin lesions are usually the first manifestation of LCH in 80% of patients. Usually, cutaneous presentations of LCH in adults are generalized or seborrhea-like lesions and it is often the first manifestation of disease. Here, we describe a 45-year old female who was known case of hypothyroidism, systemic lupus erythematosus, and diabetes insipidus. In our patient, cutaneous involvement was unusual. It was single and presented in unusual site (ankle) and before developing such lesion, she had diabetes insipidus for several years due to the involvement of pituitary gland.

Successful management of multiple-systemic Langerhans cell histiocytosis involving endocrine organs in an adult: A case report and review of literature

RATIONALE

Langerhans cell histiocytosis (LCH) involving non-endocrine organs has been frequently reported, whereas LCH involving endocrine organs is rare and the mechanism is unclear.

PATIENT CONCERNS

We report a case of multiple-systemic Langerhans cell histiocytosis (LCH) that first manifested with thyroid goiter, followed by pituitary and liver involvement.

DIAGNOSES

The diagnosis was confirmed based on immunohistochemistry of the thyroid and liver.

INTERVENTIONS

The patient was treated with thyroidectomy combined with chemotherapy and radiation therapy for thyroid and liver, respectively.

OUTCOMES

Surprisingly, the patient presented with clinical remission and no new lesion of LCH was found during follow-up over 10 years.

LESSONS

LCH involving the endocrine system is unusual and easily misdiagnosed or delayed, especially when the thyroid and pituitary glands are involved. Pathological examination is necessary for a definitive diagnosis. Regular examinations, such as anterior and posterior pituitary hormones, should be especially evaluated annually in the patients with LCH involving endocrine system.

Congenital Langerhans cell histiocytosis: a good prognosis disease?

Langerhans cell histiocytosis is rare and more frequent in children. The skin is affected in 50% of the cases and is the only site in 10%. Its course varies from self-limited and localized forms to severe multisystemic forms. Congenital cases are usually exclusively cutaneous and self-limited, with spontaneous remission in months. This study presents a rare congenital case, initially restricted to the skin, with subsequent dissemination and fatal outcome. A male newborn presented congenital disseminated erythematous scaly lesions. The biopsy was conclusive for Langerhans cell histiocytosis. The patient evolved into the multisystemic form in weeks, when chemotherapy was started, according to the LCH-2009 protocol; however, the patient was refractory to treatment and died.

Clinical implications of oncogenic mutations in pulmonary Langerhans cell histiocytosis

PURPOSE OF REVIEW

Langerhans cell histiocytosis (LCH) is a neoplasm of dendritic cells with a wide clinical spectrum. Localized pulmonary LCH occurs in young adults with a history of smoking and can either resolve spontaneously or lead to progressive decline in pulmonary function. Young children can also present with localized disease - frequently bone or skin - or with multifocal or multisystem disease. Clinical outcomes in these patients also vary widely, ranging from spontaneous resolution to multiorgan failure and death. This review describes recent developments in our understanding of the underlying pathogenesis of LCH and how these discoveries and other research are affecting how the disease is classified, treated and monitored.

RECENT FINDINGS

Somatic mutations resulting in activation of the mitogen-activated protein kinase (MAPK) pathway were recently identified as a key pathogenetic mechanism in both pediatric and pulmonary LCH.

SUMMARY

Knowledge of underlying pathogenetic mechanisms of LCH transforming how this disease and other histocytic/dendritic disorders are classified, treated and monitored.

The multiple faces of Langerhans cell histiocytosis in childhood: A gentle reminder

Langerhans cell histiocytosis (LCH) is a rare hematologic disorder that results from the clonal multiplication and accumulation of immature dendritic Langerhans cells. Its reported incidence rate varies, but is considered to be 2.6-8.9 per million children who are <15 years of age each year. It may affect any system or organ. The present study reported 4 pediatric LCH cases in order to highlight the heterogeneity of the initial presentation, and the pitfalls that may mislead clinicians and delay diagnosis. The clinical features, as well as the pathognomonic imaging, pathology findings and treatment options were presented. LCH may be rare, but it should always be included in the differential diagnosis of persistent eczema, unexplained skin lesions, diabetes insipidus and persistent bone pain, among others. While the debate on pathogenesis and treatment is ongoing, high index of suspicion among pediatricians, pediatric oncologists and other specialists (pathologists, dermatologists, orthopaedic surgeons, general practitioners or family physicians) is essential for early diagnosis, and optimal outcome.

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

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

Ninety-year-old man with hypereosinophilia, lymphadenopathies and pruritus

We report a case of a 90-year-old man with hypereosinophilia, lymphadenopathies and skin lesions, namely lichenification and pruritus. An aetiological investigation was performed, and a bone marrow (BM) biopsy and aspirate showed a hypercellular marrow with hypereosinophilia without dysmorphia or abnormal elements, and the BM and inguinal node's immunophenotyping denied any presence of abnormal lymphoid cell population. The inguinal node biopsy revealed a multinodular proliferation of large cells S100 and CD1a⁺, and a diagnosis of Langerhans cell histiocytosis was made. The hypereosinophilia and skin lesions were managed with corticotherapy with substantial improvement of cutaneous lesions and lymphadenopathies and normalisation of eosinophil count. Finally, to define if it is a single or multisystem disease, a skin biopsy will be necessary.

A rare case of solitary unifocal Langerhans cell histiocytosis with orbital extension: Diagnostic dilemma

Langerhans cell histiocytosis (LCH) is rarely encountered in ophthalmology practice. It is a spectrum of disorder characterized by accumulation of histiocytes in various tissues. Diagnosis is challenging as it may simulate periorbital hematoma, rhabdomyosarcoma, and neuroblastoma. We report a case of unifocal LCH with orbital extension. Diagnosis was obtained from incisional biopsy, and histopathological examination showed numerous histiocytes with eosinophilic infiltrations. The presence of Langerhans cells was confirmed by the presence of protein S-100, CD1a, and/or Langerin (CD207). Treatment depends on the degree of organ involvement. She responded well to cytotoxic drugs and steroids. This emphasized that prompt tissue diagnosis is crucial for early management.

Clinical course of the bony lesion of single-system single-site Langerhans cell histiocytosis - Is appropriate follow-up sufficient treatment?

BACKGROUND

Langerhans cell histiocytosis (LCH) is categorized into three types, which include single-system single-site (SS-s), single-system multiple-site (SS-m) and multisystem (MS). The most commonly affected site in LCH is bone, and the bony lesion of SS-s LCH has a good prognosis. The bony lesion of SS-s LCH has been thought to regress spontaneously. Although treatments such as curettage, direct injection of corticosteroids, and chemotherapy have been performed, regular follow-up is the first line of treatment for the bony lesion of SS-s LCH. For preventing orthopedic sequelae, strict and appropriate follow-up should be performed, but the appropriate period and method of follow-up has not yet been established.

METHODS

In the present study, we retrospectively analyzed a series of 7 cases of patients with SS-s LCH with a bony lesion treated in the Department of Orthopedic Surgery at Kagoshima University Hospital (Kagoshima, Japan) from 2006 to 2015.

RESULTS

The bony lesion regressed spontaneously in all patients. Factors such as location, size, preoperative C-reactive protein (CRP) value, standardized uptake (SUV) value of positron emission tomography (PET), age, sex and direct steroid injection were not related to the clinical course. Temporary expansion of the lesion occurred in 3 patients and a temporary worsening of pain occurred in 1 patient during the follow-up period. These events occurred within 6 weeks after biopsy.

CONCLUSION

Careful follow-up and the use of an appropriate orthosis can lead to a good clinical course for the bony lesion of SS-s LCH. Future research should seek to determine the appropriate follow-up period.

RAF/MEK/extracellular signal-related kinase pathway suppresses dendritic cell migration and traps dendritic cells in Langerhans cell histiocytosis lesions

Langerhans cell histiocytosis (LCH) is an inflammatory myeloid neoplasia characterized by granulomatous lesions containing pathological CD207⁺ dendritic cells (DCs) with constitutively activated mitogen-activated protein kinase (MAPK) pathway signaling. Approximately 60% of LCH patients harbor somatic BRAFV600E mutations localizing to CD207⁺ DCs within lesions. However, the mechanisms driving BRAFV600E⁺ LCH cell accumulation in lesions remain unknown. Here we show that sustained extracellular signal-related kinase activity induced by BRAFV600E inhibits C-C motif chemokine receptor 7 (CCR7)-mediated DC migration, trapping DCs in tissue lesions. Additionally, BRAFV600E increases expression of BCL2-like protein 1 (BCL2L1) in DCs, resulting in resistance to apoptosis. Pharmacological MAPK inhibition restores migration and apoptosis potential in a mouse LCH model, as well as in primary human LCH cells. We also demonstrate that MEK inhibitor-loaded nanoparticles have the capacity to concentrate drug delivery to phagocytic cells, significantly reducing off-target toxicity. Collectively, our results indicate that MAPK tightly suppresses DC migration and augments DC survival, rendering DCs in LCH lesions trapped and resistant to cell death.