Langerhans cell histiocytosis in children: History, classification, pathobiology, clinical manifestations, and prognosis

Characteristics and Treatment Outcomes of Pediatric Langerhans Cell Histiocytosis with Thymic Involvement

OBJECTIVE

To evaluate the characteristics and treatment outcomes of patients with pediatric Langerhans cell histiocytosis (LCH) with thymic involvement.

STUDY DESIGN

We retrospectively described the clinical, biological, and imaging characteristics of a series of 19 patients with pediatric LCH with thymic involvement in our center between September 2016 and December 2019. We further analyzed the treatment response and outcomes of patients treated with chemotherapy or targeted therapy.

RESULTS

Thymic involvement was found in 4.4% of a 433-consecutive pediatric LCH cohort; all LCH-thymic involvement presented with multisystem disease. Patients with thymic involvement were typically younger, harboring more lung and thyroid involvement and less bone involvement than those without thymic involvement. Most patients with thymic involvement had alteration of immunocompetence with decreased numbers of T-lymphocyte subsets and immunoglobulin G levels. Overall, 47.1% of patients demonstrated a response after 6 weeks of induction therapy, and 92.3% of the patients who did not respond to the first-line treatment had resolution of thymus after the second-line and/or targeted therapy. The progression/relapse rate showed no difference between patients who shifted to second-line therapy and those to dabrafenib (33.3% vs 25%, P = 1.000). The survival for patients with thymic involvement did not differ from those without thymic involvement. More patients treated with second-line chemotherapy had severe adverse events than those given dabrafenib (88.9% vs 0, P < .001).

CONCLUSIONS

Thymic involvement was observed rarely in LCH and had specific clinical characteristics. Chemotherapy could resolve most thymic lesions, and BRAF inhibitors might provide a promising treatment option with less toxicity for infants with BRAF-V600E mutation.

TRIAL REGISTRATION

http://www.chictr.org.cn, identifier: ChiCTR2000030457 (BCH-LCH 2014 study); ChiCTR2000032844 (dabrafenib study).

Multisystem Langerhans cell histiocytosis: Literature review and case report

Langerhans cell histiocytosis (LCH) refers to a group of diseases of unknown etiology, typically discovered in childhood, characterized by the accumulation of Langerhans cells (white blood cells with large cell nuclei that may contain cytoplasmic histiocytosis X bodies) involving one or more organ systems, including bones, lungs, pituitary gland, skin, lymph nodes, and liver. This disease is also known as histiocytosis X or eosinophilic granuloma. Pulmonary LCH is common (identified in 40% of LCH patients) and may be isolated to the lung or involve other organs. Although LCH is characterized by clonal cell proliferation, adult LCH is considered likely to represent the manifestation of an aberrant immune response to an unspecified antigenic stimulus rather than a manifestation of tumor proliferation. We report a very complicated clinical case of LCH, with multiple organ damage that received a variety of different diagnoses. An LCH diagnosis was confirmed based on postoperative spinal cord pathology results and immunohistochemistry examinations. This case report highlights the clinical, laboratory, and imaging signs observed in this case that should be noted to help doctors more quickly recognize, diagnose, and treat similar cases.

Dermoscopic feature analysis of different skin lesions of Langerhans cell histiocytosis

Dermoscopy was used to investigate skin lesions in 15 children with Langerhans cell histiocytosis (LCH). Purplish red globules or patches could be seen in different rashes under dermoscopy, and histopathology showed extravasation of red blood cells. Dermoscopy findings were highly consistent with histopathology results. Purplish red globules or patches could be used as important features in dermoscopy test and differential diagnosis.of LCH.

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

BACKGROUND

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

CASE SUMMARY

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

CONCLUSION

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

A Risk Model Composed of Complete Blood Count, BRAF V600E and MAP2K1 Predicts Inferior Prognosis of Langerhans Cell Histiocytosis in Children

Background

In children, Langerhans cell histiocytosis (LCH), which is the most prevalent histiocytic disorder, exhibits a wide variety of manifestations and outcomes. There is no standard prognosis evaluation system for LCH. We investigated the combined predictive significance of complete blood counts (CBCs), BRAF V600E and MAP2K1 in childhood LCH.

Methods

A cohort of 71 childhood LCH patients was retrospectively studied. The prognosis predictive significance of platelet-to-lymphocyte ratio (PLR), neutrophil-to-lymphocyte ratio (NLR), systemic inflammation response index (SIRI), systemic immune inflammation index (SII), BRAF V600E, and MAP2K1 were analyzed.

Results

Histiocyte Society (HS) classification of LCH patients was correlated with NLR, SIRI, and progression free survival (PFS), bone involvement was correlated with SIRI, liver involvement was correlated with NLR, SII, SIRI, and PFS, spleen involvement was correlated with SIRI, lung involvement was correlated with NLR and PFS, CNS involvement was correlated with PFS, while BRAF V600E was correlated with PLR, NLR, SIRI, SII, PFS, and OS (p <0.05). MAP2K1 was correlated with NLR, SIRI, PFS, and OS (p <0.05). Elevated NLR, PLR SIRI, and SII predicted inferior PFS and OS (p <0.05). PLR, NLE, SIRI, SII, BRAF V600E, and MAP2K1 were used to establish a risk model for stratifying the LCH patients into 3 different risk groups. Respective median PFS for low-, mediate-, and high-risk groups were not reached, 26, and 14 months (p <0.001), and all median OS were not reached (p <0.001).

Conclusion

The risk model combined with CBCs, BRAF V600E, and MAP2K1 might be a promising prognostic system for LCH in children.

Diagnostic Challenge in Rapidly Growing Langerhans Cell Histiocytosis with Aneurysmal Bone Cyst in the Maxilla: A Case Report

Langerhans cell histiocytosis (LCH) is a rare neoplastic disorder characterized by the clonal proliferation of CD1a +/CD 207 + dendritic cells, whose features are similar to those of epidermal Langerhans cells. LCH is more common in children than in adults. Localized osteolytic lesions in the craniofacial bones are the most common manifestations of LCH. However, LCH can also present as a multifocal and multisystem disease with poor prognosis. Locally aggressive LCH needs to be differentiated from various diseases such as osteomyelitis, malignant bone tumors, and soft tissue sarcomas. However, it is difficult to diagnose, since the imaging findings are nonspecific. We report a case of a highly aggressive LCH in the maxilla accompanied by a fluid-fluid level.

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.

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

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

A Hematologic Disease Disguised as Cutaneous Candidiasis

Langerhans cell histiocytosis is a rare hematologic neoplasm with a myeloid origin, which can affect numerous organs, the skin being the second most frequently affected by this disease. In this report, a case of a 44-year-old female, who was intermittently followed due to a suspected persistent cutaneous candidiasis in which a skin biopsy revealed Langerhans cell histiocytosis with immunohistochemistry positive for CD1a and S100 protein, is described. The management of Langerhans cell histiocytosis is difficult because these disorders respond inconsistently to immunosuppressive and chemotherapeutic strategies. The authors present this case to highlight a differential diagnosis of refractory cutaneous candidiasis and raise awareness of the importance of skin biopsy in these cases.

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.

Scalp Nodules and Facial Droop in an Infant

A previously healthy, term, 5-week-old girl initially presented to her primary care physician with a solitary, enlarging scalp nodule. The infant was otherwise well without additional signs or symptoms of illness. Over the next several weeks, the nodule continued to grow, and additional lesions appeared on her scalp. An ultrasound of the primary nodule revealed a hypoechoic structure favored to represent a serosanguinous fluid collection. After evaluation by general surgery and dermatology, she underwent a scalp biopsy of the largest lesion. While biopsy specimen results were pending, her parents noted that she was developing increased irritability, difficulty closing her right eye, and facial weakness. She was referred to the emergency department where a right-sided facial droop involving the brow and forehead was noted. The skin biopsy specimen results, along with subsequent laboratory studies and imaging, led to the final diagnosis.

Characterization of PD-1/PD-L1 immune checkpoint expression in the pathogenesis of musculoskeletal Langerhans cell histiocytosis: A retrospective study

Recent data suggest that programmed cell death -1 (PD-1) and programmed cell death ligand-1 (PD-L1) are involved in the pathogenesis of Langerhans cell histiocytoma (LCH); however, their contributions are not well established. Also, the involvement of PD-1/PD-L1 molecules in musculoskeletal LCH remains particularly unclear. The current study aims to characterize the involvement of PD-1/PD-L1 immune checkpoint system in the pathogenesis of musculoskeletal LCH. PD-1/PD-L1 expression was evaluated in 6 patients, 3 men and 3 women with a mean age of 13.5 years, with musculoskeletal LCH who were treated at Kindai University Hospital and Osaka Women's and Children's Hospital between November 2005 and December 2020. The median follow-up period for all patients with musculoskeletal LCH was 41 months. We surveyed symptoms, number of lesions, treatment modality, and outcomes. Immunostaining for CD4, CD8, PD-1, and PD-L1 was also performed on pathological specimens obtained by biopsy. Multiple lesions were observed in 5 cases, and a single lesion was observed in 1 case. The chief complaint in 5 cases was pain. Four patients underwent spontaneous regression. The other 2 patients received chemotherapy. The outcomes included continuous disease-free (n = 5) and alive with the disease (n = 1). The CD4-, CD8-, PD-1-, and PD-L1-positive rates among all specimens were 100%, 100%, 16.6%, and 83.3%, respectively. The CD4/PD-L1, CD8/PD-L1, and PD-1/PD-L1 positive rates in all the specimens were 83.3%, 83.3%, and 16.6%, respectively. We believe that the PD-1/PD-L1 immune checkpoint molecules may play some role in the microenvironment of musculoskeletal LCH.

Epidemiology of paediatric central nervous system tumours in Queensland, Australia

Within Australia, there is little epidemiologic information regarding paediatric central nervous system (CNS) tumours. This study examined the epidemiology of childhood CNS tumours at Queensland Children's Hospital (QCH), the major paediatric referral centre for Queensland and northern New South Wales. We assessed the data from 221 newly diagnosed childhood CNS tumours across a five-year period from 2015 to 2019. Recurrent tumours were excluded. Data was collected on patient age, gender, histopathological diagnosis, tumour grade, anatomical site, and residential geographical location. The incidence within this period ranged from 2.65 to 3.85 cases per 100,000 children. The median symptom interval was 30 days (IQR 14-122) with presenting features similar to previous studies. The symptom interval was shorter for children zero to three years compared to children four years or older. The most frequent tumour was pilocytic astrocytoma, followed by medulloblastoma and Langerhans cell histiocytosis. The posterior fossa was the most frequent anatomical location for tumours. Our study demonstrated a shorter symptom interval in comparison to previous literature. The study was able to determine the incidence and presenting features within an Australian population.

A deep learning-machine learning fusion approach for the classification of benign, malignant, and intermediate bone tumors

OBJECTIVES

To build and validate deep learning and machine learning fusion models to classify benign, malignant, and intermediate bone tumors based on patient clinical characteristics and conventional radiographs of the lesion.

METHODS

In this retrospective study, data were collected with pathologically confirmed diagnoses of bone tumors between 2012 and 2019. Deep learning and machine learning fusion models were built to classify tumors as benign, malignant, or intermediate using conventional radiographs of the lesion and potentially relevant clinical data. Five radiologists compared diagnostic performance with and without the model. Diagnostic performance was evaluated using the area under the curve (AUC).

RESULTS

A total of 643 patients' (median age, 21 years; interquartile range, 12-38 years; 244 women) 982 radiographs were included. In the test set, the binary category classification task, the radiological model of classification for benign/not benign, malignant/nonmalignant, and intermediate/not intermediate had AUCs of 0.846, 0.827, and 0.820, respectively; the fusion models had an AUC of 0.898, 0.894, and 0.865, respectively. In the three-category classification task, the radiological model achieved a macro average AUC of 0.813, and the fusion model had a macro average AUC of 0.872. In the observation test, the mean macro average AUC of all radiologists was 0.819. With the three-category classification fusion model support, the macro AUC improved by 0.026.

CONCLUSION

We built, validated, and tested deep learning and machine learning models that classified bone tumors at a level comparable with that of senior radiologists. Model assistance may somewhat help radiologists' differential diagnoses of bone tumors.

KEY POINTS

• The deep learning model can be used to classify benign, malignant, and intermediate bone tumors. • The machine learning model fusing information from radiographs and clinical characteristics can improve the classification capacity for bone tumors. • The diagnostic performance of the fusion model is comparable with that of senior radiologists and is potentially useful as a complement to radiologists in a bone tumor differential diagnosis.

Isolated Bone Lesions in the Mandible and Maxilla of Langerhans Cell Histiocytosis Treated with Fractionated Stereotactic Low-Dose Radiotherapy: Case Report and 5-Year Follow-Up

Langerhans cell histiocytosis is a benign histiocytic disorder touching both genders and can occur at any age. It is currently classified by the Histiocyte Society as an inflammatory myeloid neoplasm of mixed cellularity. Clinically, it is illustrated by single or multiple osteolytic bone lesions associated with ulceration of the skin and soft tissues. Disease outcome is highly variable, depending on the degree of involvement. Bone pathologies are observed in 60% of cases as uni- or multifocal lesions. Several treatment modalities have been proposed and include surgical excision, intralesion steroid injection, chemotherapy, and low-dose radiotherapy. In this paper, we report a case of a 42-year-old male suffering from gingival swelling in the left side of his mandible and the right side of the maxilla. Clinical, radiological, and histological examinations confirm the diagnosis of Langerhans cell histiocytosis. Hematological investigation, entire body CT scan, and bone scintigraphy confirmed the limitation of the lesions in the right maxilla and on the left mandible. The lesions were treated with fractionated stereotactic low-dose radiotherapy, 24 Gy in 16 fractions, by using a linear accelerator with a custom-made rigid mask for accurate immobilization of the head with confirmed precision, which allows noninvasive approaches. Complete remission was achieved clinically and radiologically after one year, and a panoramic X-ray after 5 years confirms the bone healing process. Fractionated stereotactic low-dose RT could be adopted as an effective treatment.

Langerhans cell histiocytosis in the oral and maxillofacial region: An update

BACKGROUND

Langerhans cell histiocytosis (LCH) is a rare disorder characterized by abnormal proliferation and infiltration of histiocytic cells.

METHODS

This review focused on the main aspects associated with LCH.

RESULTS

LCH can involve single or multiple organs and systems, with bone and skin being the most commonly affected sites. Regarding skeletal manifestations, the jawbones are involved in about 20%-30% of all cases. Such lesions may present as unilocular or multilocular images mainly affecting the posterior mandible. Oral soft tissue lesions may also occur, with the gingiva and hard palate being the most frequently affected sites.

CONCLUSION

The diagnosis and management of LCH are challenging, requiring a multidisciplinary approach, with dentists playing a central role since oral manifestations can be the first sign of the condition.

Frequency detection of BRAF V600E mutation in a cohort of pediatric langerhans cell histiocytosis patients by next-generation sequencing

BACKGROUND

Langerhans cell histiocytosis (LCH) is a rare neoplastic disease that occurs in both children and adults, and BRAF V600E is detected in up to 64% of the patients. Several studies have discussed the associations between BRAF V600E mutation and clinicopathological manifestations, but no clear conclusions have been drawn regarding the clinical significance of the mutation in pediatric patients.

RESULTS

We retrieved the clinical information for 148 pediatric LCH patients and investigated the BRAF V600E mutation using next-generation sequencing alone or with droplet digital PCR. The overall positive rate of BRAF V600E was 60/148 (41%). The type of sample (peripheral blood and formalin-fixed paraffin-embedded tissue) used for testing was significantly associated with the BRAF V600E mutation status (p-value = 0.000 and 0.000). The risk of recurrence declined in patients who received targeted therapy (p-value = 0.006; hazard ratio 0.164, 95%CI: 0.046 to 0.583). However, no correlation was found between the BRAF V600E status and gender, age, stage, specific organ affected, TP53 mutation status, masses close to the lesion or recurrence.

CONCLUSIONS

This is the largest pediatric LCH study conducted with a Chinese population to date. BRAF V600E in LCH may occur less in East Asian populations than in other ethnic groups, regardless of age. Biopsy tissue is a more sensitive sample for BRAF mutation screening because not all of circulating DNA is tumoral. Approaches with low limit of detection or high sensitivity are recommended for mutation screening to avoid type I and II errors.

A possible case of Langerhans-cell histiocytosis? Differential diagnosis in a rare case from the Late Antiquity Bavaria (Germany)

OBJECTIVE

To outline the importance of accurate diagnosis in ancient rare diseases by presenting a possible case of Langerhans-cell histiocytosis.

MATERIALS

Skeletal elements from a well-preserved skeleton of a nine to eleven-year-old, probably female child who lived around 300-400 AD Late Roman Neuburg / Donau (Germany).

METHODS

Macroscopic, radiologic, light and scanning-electron microscopic and physical techniques were used.

RESULTS

Resorptive defects, particularly in the cranium, but also in the left hip bone and the right femur, suggest the presence of Langerhans-cell histiocytosis macroscopically and radiologically. The presence of morphological changes along the edges of osteolytic lesions and in the diploic spaces appear to be post-mortem artifacts based on microscopic investigation and elemental analysis.

CONCLUSIONS

Re-evaluation of morphological structures and elemental constitution of lesions is critical to differential diagnosis. In the case examined here, the identification of post-mortem structures rules out the former diagnosis of Langerhans-cell histiocytosis. Re-evaluation of cases of rare diseases require applying a range of methods during the analysis, as every single case makes a difference in the numbers of this very small group of diseases.

SIGNIFICANCE

This study emphasizes the importance of utilizing different analytical techniques to avoid false diagnoses.

LIMITATIONS

Not all morphological features can reliably be diagnosed using microscopic and elemental techniques.

SUGGESTIONS FOR FURTHER RESEARCH

In the case of rare diseases that are difficult to diagnose, the widest possible spectrum of techniques should always be used, particularly microscopy.

Radiologic findings that aid in the reduction of misdiagnoses of Langerhans cell histiocytosis of the bone: a retrospective study

BACKGROUND

This study aimed to identify the characteristic radiological signs for the diagnosis of Langerhans cell histiocytosis (LCH) of the bone.

METHODS

We retrospectively studied 82 cases of LCH with bone lesions confirmed by pathology. Clinical and radiological features of the patients were analyzed.

RESULTS

A total of 64 and 18 patients had single and multiple bone lesions, respectively. With regard to LCH with single bone lesions, 37.5% (24/64) of lesions were located in the skull and presented as bone destruction with or without soft tissue mass. The correct diagnosis rate of these lesions was 60.0% (9/15) in children and adolescents, but was only 22.2% (2/9) in adults. A total of 26.5% (17/64) of the solitary lesions were found in the spine. Of these, 88.2% (15/17) were located in the vertebral body and appeared to have different degrees of collapse, and 66.7% (10/15) of these lesions were correctly diagnosed. Of the unifocal lesions, 21.8% (14/64) were located in other flat and irregular bones and manifested as osteolysis. Only 21.4% (3/14) of these cases were correctly diagnosed. In total, 14.1% (9/64) of the isolated bone LCH lesions were located in the long bones. Of these, 77.8% (7/9) were located in the diaphysis and presented as central bone destruction with or without fusiform periosteal reaction and extensive peripheral edema, of which 42.9% (3/7) were correctly diagnosed before surgery or biopsy. With regard to LCH with multiple bony destructive lesions, 71.4% (10/14) of cases in children and adolescents were correctly diagnosed; however, all four cases among adults were misdiagnosed.

CONCLUSION

In all age groups, isolated diaphyseal destruction of the long bone with fusiform periosteal reaction and extensive peripheral edema, vertebra plana of the spine, and bevelled edge of skull defects accompanied by soft tissue masses strongly suggest LCH diagnosis. Moreover, the multiple bone osteolytic destruction in children and adolescents strongly suggests LCH diagnosis. Familiarity with these typical radiological signs of LCH is necessary to decrease misdiagnoses.

Treatment Outcomes of Langerhans Cell Histiocytosis: A Retrospective Study

Background and Objectives: Langerhans cell histiocytosis (LCH) is a rare disease characterized by the infiltration of one or more organs by Langerhans cell-like dendritic cells. LCH often involves the bone, and its clinical evidence is limited. The purpose of this study is to report on the treatment of LCH at our institution and to add to the evidence for LCH. Materials and Methods: We reviewed six cases of LCH treated in our hospital between November 2005 and February 2016. Patient age at the first visit, sex, site of origin, symptoms, image tools used for diagnosis, biopsy site, complications, treatment, and final clinical outcome were evaluated. The median follow-up period was 41 months. Results: The median patient age at the first visit was 13.5 years. Three male and three female individuals were enrolled. Multiple lesions were observed in five cases, and a solitary lesion was observed in one case. Pain was the chief complaint in five cases. Radiography was the most commonly used imaging tool. Bone scintigraphy or magnetic resonance imaging and positron emission tomography-computed tomography were also used to diagnose systematic LCH. Biopsy of the femur was performed in two cases, and biopsy of the tibia, lumbar vertebrae, rib, and radius was performed in one case each. Regarding comorbidities, one case of hepatitis B and one case of autism were observed. Chemotherapy was initiated in two patients. The other four patients were observed naturally. Continuous disease-free survival was observed in five patients. One patient remained alive but not without disease during the final follow-up examination. Conclusion: LCH should be diagnosed as early as possible to treat it appropriately.

Discrepancies between F-18-FDG PET/CT findings and conventional imaging in Langerhans cell histiocytosis

BACKGROUND

Accurate risk stratification of Langerhans cell histiocytosis (LCH) is essential as management can range from conservative in single system, low risk for central nervous system (CNS) involvement lesions to intensive chemotherapy for multisystem or high-risk disease. Additionally, being able to differentiate metabolically active from inactive lesions is essential for both prognostic reasons and to avoid potentially unnecessary treatment.

METHODS

A retrospective review was performed on all patients with histopathology-confirmed LCH at Cincinnati Children's Hospital Medical Center (CCHMC) between 2009 and 2019.

RESULTS

One hundred seven positron emission tomography (PET)/computerized tomography (CT) images were included in the review. A discrepancy between PET/CT and conventional imaging occurred on 53 occasions. On 13 occasions, increased uptake was observed on PET in an area with no identifiable lesion on conventional imaging. On 40 occasions, lesions were found on conventional imaging where no increased uptake was observed on PET. On eight skeletal surveys, three other radiographs, four diagnostic CTs, five localization CTs, and one bone scan, no lesion was identified in an area with increased fluorodeoxyglucose (FDG) uptake. This occurred exclusively in bone. On nine skeletal surveys, one other radiograph, four diagnostic CTs, six localization CTs, 19 magnetic resonance imaging (MRI) scans, and one bone scan, a lesion was identified in a location without increased FDG uptake. This occurred in bone, CNS, and lungs.

CONCLUSION

F-18-FDG PET/CT is vital in the evaluation of LCH lesions given its ability to detect LCH lesions not detectable on conventional imaging modalities, as well as its ability to distinguish metabolically active from inactive disease. MRI and diagnostic CT are still useful adjunctive tests for identification of CNS and lung lesions.

[Bone and soft tissue Langerhans cell histiocytosis with multinucleated giant cells and BRAF V600E mutation]

Langerhans cell histiocytosis (LCH) is a heterogeneous disease characterized by proliferation of Langerhans cells and BRAF mutation in almost half of the cases. Bone involvement is common but large soft tissue disease is uncommon. We report a pediatric patient with a large tumor mass involving the left iliac bone and the adjacent soft tissue. The computed tomography scan showed an osteolytic lesion with soft tissue extension. Surgical curettage of the lesion was performed and the final histopathologic diagnosis was LCH with CD1a immunoreactivity in tumor cells. The molecular analysis revealed a BRAF V600E mutation. We discuss the histopathological and immunohistochemical differential diagnosis with histiocytosis other than LCH.

Adult multifocal Langerhan's cell histiocytosis involving periodontal tissues

Langerhans cell histiocytosis (LCH) is a rare inflammatory neoplasia characterized by uncontrolled stimulation and abnormal proliferation of Langerhans cells (LCs). It can present as unifocal or multifocal with local and systemic manifestations which involves various internal organs and mucosal tissues. The clinical course varies among individuals, ranges from spontaneous resolution to life-threatening conditions with multisystem involvement. Prognosis relies on the involvement of risk organs (liver, spleen, and bone marrow) at diagnosis, mainly on organ dysfunction, and response to initial therapy. The diagnosis is based on histological study of tissues samples and shows tissue infiltration with LCs and the tumor cells immunopositive for s100/CD1a/Langerin/CD68 focal). In the oral cavity, LCH affects the alveolar or cortical bone and causes ulcerated lesions involving various mucosal and periodontal tissues. This article reports a case of adult multifocal LCH involving periodontal tissues with 1½ year posttreatment follow-up showing regression of the lesion.

Unisystem Langerhans cell histiocytosis in maxillofacial region in pediatrics: comprehensive and systematic review

BACKGROUND

The study aimed to identify, enlist, and analyze cases of unisystem LCH in the maxillofacial pediatric population to understand the clinical presentation and encourage the consideration of this rare disease in the differential diagnosis. Langerhans cell histiocytosis (LCH) is an aggressive benign condition affecting mainly the pediatric population. It can be easily masked as periodontal disease in the maxillofacial region. Early diagnosis and a systemic evaluation are of utmost importance.

METHODOLOGY

We are presenting a complete review of literature in the pediatric population according to PRISMA guidelines for clinicopathologic, histopathological, immunohistochemistry, and treatment for unisystem LCH. The risk of bias assessment across studies was done using a Case series appraisal checklist by Guo et al. 53 RESULTS: Forty-nine articles (152 cases) were selected which met our inclusion and exclusion criteria to be included in our review. Most of the patients fall in 6-12 years of age with the involvement of the mandibular body region in 40.79% cases. This disease mainly presents as erythematous gingiva, pain, swelling, and mobile teeth. Management can range from minimal intervention to chemotherapy and surgery.

CONCLUSION AND PRACTICAL IMPLICATIONS

Although this is a rare condition, it should be considered especially in the pediatric population with periodontitis type lesions and floating teeth and comprehensive management should be followed. Early diagnosis of the disease is very important.

Multifocal Langerhans Cell Histiocytosis: A Unique Presentation of Eosinophilic Granuloma with Intracranial Extension, Massive Lymphadenopathy, and Epstein-Barr Viral Infection in an Adolescent Female

We report the case of an otherwise healthy 17-year-old female who presented for surgical removal of an enlarging “atypical cyst” on her scalp. During subtotal excision, only friable serosanguinous translucent ribbons of tissue were found. A histopathologic diagnosis of Langerhans cell histiocytosis (LCH) was rendered and imaging studies revealed extradural invasion of the tumor. Within weeks, the patient also developed progressive lymphadenopathy with grossly elevated levels of Epstein-Barr virus viral capsid antigen antibody levels. This report aims to highlight a unique presentation of LCH with discussion of workup, management, and avoidance of potential surgical complications.

Head and neck tumors in children and adolescents: Impact of a multidisciplinary tumor board

INTRODUCTION

Cancer treatment in France is based on Multidisciplinary Tumor Board (MTB). In the Ile-de-France region (IDF), which includes 12 million inhabitants from Paris and the surrounding area, pediatric tumors of head and neck are discussed since 2013 in a dedicated Interregional Pediatric Multicentric MTB (IPMTB). The purpose of this study is to analyze the impact of the IDF head and neck IPMTB on the management of these tumors, 5 years after their implementation.

MATERIALS AND METHODS

Retrospective study of all patient files presented in the IPMTB for a benign or malignant head-and-neck tumor, between 2013 and 2018.

RESULTS

A total of 679 discussions were analyzed representing 428 patients. Median age was 7.5 years (range: 0-31 years). Malignant tumors represented 71% of cases, including 36% of rhabdomyosarcoma. Overall, 12% percent of the cases discussed came from centers outside of IDF. All meetings complied with multidisciplinary criteria required by French law. Proposals made during the IPMTB were followed in 86% of cases. Among the 251 proposals made by the referring teams prior to the IPMTB, 29% were secondarily modified after being discussed in the IPMTB.

CONCLUSION

Thanks to their multidisciplinarity, high number of cases discussed and usual respect of their proposals, the IPMTB have made it possible to improve the coordination between all specialties involved in the patient's management, to apply the most recent and scientifically validated protocols, and to share the knowledge of different teams concerning the management of particularly rare tumors.

Langerhans cell histiocytosis in children: A retrospective case series of 126 cases

BACKGROUND/OBJECTIVES

Langerhans cell histiocytosis (LCH), a rare neoplasm of hematopoietic myeloid precursor cells, is clinically characterized by spontaneously resolving lesions to a progressive life-threatening multisystem disorder. Diagnosing LCH in children is challenging as it mimics other skin disorders. This study describes the varied clinical presentation and disease course in children less than 18 years diagnosed with LCH.

METHODS

We performed a retrospective observational study of all cases diagnosed with LCH presenting to a children's hospital in the last 26 years. Data on history, cutaneous and systemic examination, and laboratory evaluation performed, were recorded.

RESULTS

A total of 126 children diagnosed with LCH were included in the study. There were 68% cases limited only to skin, and 32% children with multisystem involvement at the initial presentation. Scaly papules were the most common morphologic finding in skin. The skeletal system was the second most common organ system to be affected. Failure to thrive was a common symptom. Progression of skin to systemic involvement was seen in 27.9%. In 76.7%, skin lesions cleared over a period of 2 to 4 years. Complete remission was seen in 56.9% of children over a period of 3 to 7 years, while 8.1% children died of complicationsand 31.8% were lost to follow-up.

CONCLUSIONS

Long-term follow-up in this study has shown cutaneous LCH without systemic involvement has a good prognosis. Skin involvement,along with failure to thrive, was the most common clinical presentation in our study. The skeletal system was the second most common organ system involved.

Combination of Neoadjuvant Therapy and Liver Transplantation in Pediatric Multisystem Langerhans Cell Histiocytosis With Liver Involvement

Background: Langerhans cell histiocytosis (LCH) is characterized by misguided myeloid differentiation, whose prognosis was poor with involvement of risk organs. Remaining issues include how to improve the outcomes of patients with risk-organ involvement.

Methods: A retrospective study was conducted in Renji Hospital exploring the effects of neoadjuvant therapy in combination with pediatric liver transplantation (LT) for LCH patients based on data collected between October 2006 and October 2019.

Results: We presented here five cases of multisystem LCH patients underwent systemic chemotherapy to control active lesions, followed by LT to treat end-stage liver diseases. Manifestations before LT included elevated transaminase levels (n = 5, 100%), jaundice (n = 4, 80%), ascites (n = 3, 60%), and variceal hemorrhage (n = 1, 20%). Three patients underwent orthotopic liver transplantation (OLT) and two underwent living donor liver transplantation (LDLT). Until December 2019, median follow-up time was 32 months (range, 2–67 months). Liver functions significantly improved compared with pre-operative conditions. One patient had perioperative hepatic artery complications and one patient had a recurrence in the lung. EBV infection occurred in four (80%) patients and CMV infection occurred in one (20%). There was one case of drug-induced liver injury diagnosed on biopsy 13 months after LT. None underwent re-transplantation and there were no rejection or portal vein and biliary complications.

Conclusion: Combination of neoadjuvant therapy and LT is an effective paradigm in treatment of multisystem LCH with severe liver dysfunction. With advances in chemotherapy regimen for multisystem LCH and LT surgery, perspectives on prognosis for LCH children are promising.

Case series of cutaneous Langerhans cell histiocytosis in Indonesian children; The clinicopathological spectrum

Langerhans Cell Histiocytosis (LCH) is a rare disease characterized by the clonal proliferation of Langerhans cells, which are immunoreactive to S-100 and CD-1a/ CD207 (Langerin). Cutaneous involvement is the most common presentation of LCH in children. It is suggested that the patients with single-system LCH limited to the skin have a better prognosis than those with systemic involvement. Three histologic reactions of cutaneous LCH have been reported and are associated with the clinical types of LCH. These histological reactions include: proliferative, granulomatous, and xanthomatous. This study presents the clinicopathological features of ten cutaneous LCH cases collected from Dr. Sardjito General Hospital Yogyakarta Indonesia between 2014-2018. The ten cases showed various clinical features, in which some features mimic other diseases. The microscopic features of skin biopsies showed granulomatous reaction in 80% of cases and proliferative reaction in the other 20%. Five patients (50% of cases) who died had systemic manifestation of thrombocytopenia, anemia, icterus, hepatosplenomegaly, and revealed the granulomatous type from their skin biopsy specimens. The clinical recognition of LCH and subsequent histological reaction determination are important since some cases may develop multisystem disease and have a poor prognosis.

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.

Clinical and pathological features of 124 patients with indistinguishable sellar lesions and central diabetes insipidus

BACKGROUND

Sellar lesions with central diabetes insipidus have a wide range of causes, and diagnosis is relatively difficult. The indication and clinical value of biopsy are still controversial.

OBJECTIVE

To describe the etiology, demographic characteristics, manifestations, laboratory tests and imaging findings of this disease and to explore the clinical value and safety of endoscopic transsphenoidal biopsy.

METHODS

Retrospective analysis of 124 patients with sellar lesions and central diabetes insipidus who underwent endoscopic transsphenoidal biopsy at the Neurosurgery Department, Peking Union Medical College Hospital, from 2011 to 2019.

RESULTS

The main etiology includes congenital diseases, inflammatory/infectious diseases and tumor diseases. The most common diseases were germ cell tumors, Langerhans cell histiocytosis, lymphocytic hypophysitis, and Rathke's cleft cysts. Except for the age at the time of biopsy of patients with tumor diseases, which was significantly lower than that of the other two, the other clinical manifestations of the three types of diseases were not significantly different. Among the 124 patients, biopsy was performed via an endoscopic transsphenoidal approach for 101 with intrasellarly available lesions or via an endoscopic extended transsphenoidal approach for 23 with intrasellarly unavailable lesions. 6 patients had central nervous system infections after surgery, and 3 had cerebrospinal fluid rhinorrhea, of which 2 were surgically repaired. These incidences were basically the same as those of classic surgery. 2 patients had worse visual acuity, 2 had worse visual field, and 2 had worse eye movement. Excepting one patient, all of whom have recovered after treatment.

CONCLUSIONS

Noninvasive examination is difficult for identifying the common causes of this type of disease. Endoscopic transsphenoidal biopsy is relatively safe and effective, helps doctors to select the best treatment for patients, and is worth promoting.

Isolated Cutaneous Langerhans Cell Histiocytosis Presenting in an Adult Male

Langerhans cell histiocytosis (LCH) is an infrequent clonal proliferative disorder of myeloid dendritic cells. It has a wide variety of cutaneous manifestations and retains the possibility of systemic implications. Because LCH is predominantly a disease of childhood, there are well-established clinical definitions, as well as guidelines regarding workup and treatment, in the context of pediatric disease. Here we present a case of isolated cutaneous LCH in an adult male, followed by a discussion of our diagnostic plan and treatment course. The patient exhibited a small, excoriated, yellow papule on his inferior forehead during a skin examination. The specimen underwent tangential shave biopsy; histopathologic evaluation with appropriate immunohistochemical staining confirmed a diagnosis of cutaneous LCH. After thorough investigation via serologic and imaging diagnostics, we confirmed isolated cutaneous disease. The patient underwent wide local excision (WLE) with no evidence of recurrence. It is crucial to appropriately screen all patients diagnosed with cutaneous LCH for internal organ involvement. The authors aim to highlight the need for further investigations to ultimately dictate standardized management and treatment for isolated cutaneous LCH in the adult population.

Effective rescue treatment with vemurafenib of an infant with high-risk Langerhans cell histiocytosis

INTRODUCTION

The recently identified role of a BRAF somatic mutation in the pathophysiology of Langerhans cell histiocytosis (LCH) offers new therapeutic options. Herein we describe the case of a 10-month-old infant with refractory high-risk LCH successfully treated with vemurafenib.

OBSERVATION

The patient first presented with cutaneous LCH at the age of 2 months. The disease remained undiagnosed until she was 6 months old, when it rapidly evolved to a multisystemic high-risk and life-threatening disease, refractory to 2 lines of chemotherapy. BRAFV600E mutation was found at skin biopsy, and targeted therapy with vemurafenib was started when she was 10 months old. The treatment induced a fast and sustained response, but rapid relapse occurred after treatment discontinuation, leading to resumption of treatment, once more resulting in a sustained response.

CONCLUSION

Our case highlights the first-line role of dermatologists in establishing the diagnosis of LCH, especially in children, in whom the eruption may be difficult to identify, leading to delayed diagnosis. Targeted therapy with vemurafenib has recently been described in children in this indication and our results support its efficacy, highlighting the need for prolonged treatment and raising the question of maintenance therapy, as well as the necessity for large-scale and long-term studies.

[Cancer in the first 18 months of life]

INTRODUCTION

Oncological-haematological disease continues to be the first cause of non-traumatic mortality in childhood, as well as a significant cause of morbidity. The patient less than 18-months-old has special clinical, diagnostic, and therapeutic features that all paediatricians are interested in determining, with the aim of achieving greater survival and a lower morbidity throughout the lives of their patients.

MATERIAL AND METHODS

A retrospective, descriptive study was carried out using the clinical, diagnostic, and therapeutic variables in patients less than 18-months-old diagnosed with an oncological-haematological that received chemotherapy in a Paediatric Oncology Unit between January 2007 and August 2019.

RESULTS

A total of 72 patients were diagnosed with 76 cancers that required chemotherapy. The most common cancer was leukaemia (21 patients), followed by neuroblastoma (15 patients), and tumours of the central nervous system (12 patients). The presentation of "life-threatening symptoms" was seen in 20.8% of cases, particularly in tumours of neural origin (13/15). Although 18% of patients showed no symptoms on diagnosis, just over half (51%) of the diagnoses took place in the "advanced stages". Particularly in the case of solid tumours in which 23.6% were diagnosed with metastases. A significant percentage of genetic alterations implicated in the aetiopathogenesis of the different cancers were found.

CONCLUSIONS

Cancer in the first stages of life is a diagnostic and therapeutic challenge due to its phenotypical diversity, its genetic load, and its therapeutic difficulties. Knowledge of its particular features is essential for its early and effective approach.

[Mandibular Langerhans cell histiocytosis: a case report]

Langerhans cell histiocytosis is commonly found in cranial bones and rarely found in the mandible. This article presents a case of mandibular Langerhans cell histiocytosis and discusses its pathogeny, clinical features, diagnosis, and treatment.

Retrospective study of Langerhans cell histiocytosis in ear, nose and neck

OBJECTIVE

Langerhans cell histiocytosis (LCH) is a rare clinical disorder. We retrospectively analysed the clinical manifestations, treatments and prognoses of LCH cases involving the ear, nose, and neck.

MATERIALS AND METHODS

28 cases with confirmed LCH in ear, nose or neck were reviewed. We recorded patient age, sex, chief complaints, accompanying symptoms, lesional sites, radiological data, treatments and pathologies. Whole-exome sequencing was performed on the patient diagnosed with LCH and Treacher-Collins syndrome (TCS).

RESULTS

The mean age was 14.86 years. Most LCH was in the ear (93%), usually in the mastoid. The most common symptoms were an ear mass and a purulent discharge. Imaging was not very useful. Treatments included surgery, chemotherapy, and radioactive particle implantation. Some cases exhibited multisystem involvement. Most patients enjoyed good prognoses. One patient was diagnosed with both temporal LCH and TCS. Whole-exome sequencing revealed a heterozygous c.261_272delAGGTACCCTTCC(p.87_91delRGTLPinsR) mutation in exon 2 of the POLR1D gene (NM_015972).

CONCLUSION

LCH mostly occurs in children. In head and neck it affects principally the mastoid part of the temporal bone. Treatments include surgery, chemotherapy, and irradiation. Most patients enjoy good prognoses. LCH accompanied by TCS is rare and increases the difficulty of diagnosis; molecular data aid in TCS identification.

Childhood Langerhans cell histiocytosis: a disease with many faces

BACKGROUND

Langerhans cell histiocytosis (LCH) is a group of diseases characterized by the proliferation and accumulation of Langerhans cells. Clinical presentations of LCH vary widely.

DATA SOURCES

A PubMed search was conducted using Clinical Queries with the key term "Langerhans cell histiocytosis". The search strategy included meta-analyses, randomized controlled trials, clinical trials, observational studies, and reviews. This paper is based on, but not limited to, the search results.

RESULTS

Generally, patients with LCH can be divided into two groups based on the extent of involvement at diagnosis, namely, single-system LCH and multisystem LCH. The involvement may be unifocal or multifocal. Patients with isolated bone lesions typically present between 5 and 15 years of age, whereas those with multisystem LCH tend to present before 5 years of age. The clinical spectrum is broad, ranging from an asymptomatic isolated skin or bone lesion to a life-threatening multisystem condition. Clinical manifestations include, among others, "punched out" lytic bone lesion, seborrheic dermatitis-like eruption, erythematous/reddish-brown crusted/scaly papules/maculopapules/plaques/patches, and eczematous lesions, diabetes insipidus, hepatosplenomegaly, cytopenias, lymphadenopathy, and an acute fulminant disseminated multisystem condition presenting with fever, skin rash, anemia, thrombocytopenia, lymphadenopathy, and hepatosplenomegaly. The diagnosis is clinicopathologic, based on typical clinical findings and histologic/immunohistochemical examination of a biopsy of lesional tissue. Positive CD1a, S100, and/or CD207 (Langerin) immunohistochemical staining of lesional cells is required for a definitive diagnosis. Watchful waiting is recommended for patients with skin-only LCH. Patients with symptomatic or refractory skin-only LCH may be treated with topical tacrolimus/corticosteroids, topical nitrogen mustard, oral methotrexate, or oral hydroxyurea. The current recommended first-line therapy for patients with multisystem LCH is 12 months therapy with prednisone and vinblastine. Mercaptopurine is added for patients with risk organ involvements.

CONCLUSIONS

Because of the broad spectrum of clinical manifestations and the extreme diversity of disease, LCH remains a diagnostic dilemma. Morphological identification of LCH cells and positive immunochemical staining with CD1a, S100, and/or CD207 (Langerin) of lesional cells are necessary for a definitive diagnosis.