Adult Langerhans Cell Histiocytosis Research Articles

BRAF-V600E Mutation on Circulating Cell-Free DNA Is a Promising Biomarker of High-Risk Adult Langerhans Cell Histiocytosis

Background: Langerhans cell histiocytosis (LCH) is a rare disorder characterized by clonal proliferation of Langerhans cells and significant infiltration of immune cells. Although the precise pathophysiology is to be elucidated, oncogenic BRAF-V600E mutation could be detected in LCH lesions from the majority of patients (Badalian-Very, et al. Blood. 2010). Furthermore, Berres ML et al. found that patients with active, high-risk LCH carried BRAF-V600E in circulating CD11c+/CD14+ cell fractions. In patients with various kinds of cancers, circulating cell-free DNA (cfDNA) in peripheral blood contains cancer-derived genomic DNA and has been applied to non-invasive diagnostic procedure, so called liquid biopsy. In the very recent report, BRAF-V600E was successfully detected on cfDNA from patients with colorectal cancer in 100% sensitivity and specificity (Thierry AR, et al. Nature Med. 2014). Then, in this study, we evaluated BRAF mutation on cfDNA as a potential biomarker of LCH using allele-specific quantitative polymerase chain reaction (ASQ-PCR).Methods: We cloned normal and mutant BRAF alleles that include exon 15 and neighboring sequences into pCR2.1 to make the standard curve. cfDNA was prepared from plasma of adult LCH patients and was subjected to genotyping BRAF alleles by ASQ-PCR, which was specifically designed for detection of BRAF-V600E with a 3′-phosphate-modified oligonucleotide blocker according to Thierry AR, et al. Mutant BRAF load was estimated from the standard curve in each assay and was expressed as the percentage of mutant alleles to total number of alleles.Results and Discussion: Plasma cfDNA was prepared from 8 adult patients with LCH listed in Table.1 as well as normal subjects including cancer-free patients. The mean quantity of recovered cfDNA in LCH vs normal was 316.5pg/ml (median, 290.4) vs 92.0pg/ml (median, 91.8). Three high-risk patients with active multiple lesions were positive for BRAF-V600E. In these patients, the mean ratio of mutant BRAF alleles to total was 3.25 % (median, 2.59 %). Next, we compared the sensitivity of ASQ-PCR of BRAF-V600E between cfDNA and cellular DNA in the same blood sample. Naturally, too much more DNA was recovered from mononuclear cells than plasma in the same blood volume, whereas the ratio of mutant to total alleles was more than 10-fold higher in cfDNA, suggesting that LCH-derived genomes are significantly enriched in cfDNA compared with cellular DNA, and that cfDNA is more adequate for liquid biopsy in LCH with BRAF-V600E. Then, in a BRAF-V600E-positive patient, we followed the mutant BRAF load during the course of initial chemotherapy. The ratio of mutant to total alleles was estimated as 1.00% prior to chemotherapy and not detectable after one course of chemotherapy consisting of vinblastine, prednisolone, methotrexate and 6-mercaptopurine. The validity of this ASQ-PCR data was confirmed by a series of routine imaging analysis performed at the same time. Taken together, ASQ-PCR of BRAF-V600E on cfDNA may contribute to planning of risk-based treatment as well as monitoring of treatment efficacy in LCH, especially in an active, high-risk group. A number of BRAF-targeted inhibitors have been approved or under clinical trial for various cancers with BRAF mutant, and one of those, vemurafenib is also active against LCH with BRAF-V600E (Haroche J, et al. Blood. 2013). Hereafter, the utility of BRAF-V600E on cfDNA should be validated in a large cohort of LCH patients.Conclusion: In spite of a very small cohort, we demonstrated the feasibility of BRAF-V600E on cfDNA as a biomarker of active, high-risk LCH.Disclosures: This work was supported by grants from "Japan LCH Study Group" (JLSG).Can’t read 3B2 tag because stream don’t exist.Tag: _LTable15 DisclosuresKobayashi:Japan LCH Study Group (JLSG): Research Funding. Fukuyama:Pfizer Japan Inc.: Employment. Tojo:Bristol-Myers Squibb.: Research Funding; Chugai Pharmaceutical Co Ltd.: Research Funding, Speakers Bureau; Sumitomo Dainippon Pharma Co Ltd.: Research Funding; Pfizer Japan Inc.: Research Funding; Celgene: Consultancy; Novartis Pharmaceuticals Japan.: Research Funding, Speakers Bureau.

BRAFV600E mutation in cutaneous lesions of patients with adult Langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH) is characterized by the proliferation of pathologic Langerhans cells. The disease can develop in any age and can affect almost any organ. Cutaneous involvement is frequent in LCH. The recent demonstration of the activating, oncogenic BRAFV600E gene mutation in LCH samples strongly supports the neoplastic origin of the disease. Our aim was to analyse the clinical data of the patients and whether BRAFV600E mutation is present in skin lesions of patients with adult onset LCH, and to investigate whether the BRAFV600E mutation status has any effect on the clinical presentation and the outcome of the disease. We diagnosed and treated 15 adult LCH patients in the period of 1987-2012 and collected their clinical data. Three of our patients suffered from skin involvement and 12 patients had multiorgan disease (five patients out of the multisystem group died). Eleven formalin-fixed paraffin-embedded skin samples from 10 patients were available for BRAFV600E mutation analysis. Among the 11 examined samples, 6 contained the BRAFV600E mutation (54.5%). Our results indicate that in the adult group of LCH patients the presence of BRAFV600E mutation is similar to what was previously suggested in case of the childhood forms, at least as far as skin lesions are concerned. The BRAF mutation status of our patients does not seem to correlate with the extent and/or the outcome of the disease. Our results support the neoplastic origin of LCH and suggest that skin lesions of LCH are sufficient for the diagnosis of the disease and for assessing its BRAF status. In addition, analysis of BRAF status of patients with LCH can lead to the administration of new targeted therapies which may provide better disease control and prognosis.

A Rare Presentation of Langerhans Cell Histiocytosis Tonsil Infiltration: Review of the Literature: Atypical Presentation of Langerhans Cell Histiocytosis

Langerhans cell histiocytosis (LCH) is a rare disease that can infiltrate various organs. LCH presents with solitary organ involvement or as a multi-system disease. We present a patient who has tonsillary infiltration with LCH. A 74year-old Caucasian male was admitted for swelling of the neck and difficulty swallowing for 3months. Physical examination showed submandibular lymph node enlargement of approximately 3cm and tonsil enlargement. A tonsillectomy and excisional biopsy of the lymph node were done. Histiocyte-like cell infiltration was seen in the tonsil biopsy. CD3, CD20, CD15, CD30, CD5, CD138, Lambda, Kappa, Bcl-2, ALK, CD23, CD10, Bcl-6, keratin, EMA, HMB-45, and Cyl D1 were negative. CD68, S-100, CD1a, and fascin were positive, and the Ki-67 proliferation index was 20% in immunocytochemical staining. The most commonly infiltrated bones are the skull, femur, lower jaw, pelvis, and vertebrae in LCH. Oral or perioral lesions are present in 30% of cases. Oral lesions most often involve bone loss, unexpected tooth loss, and gum inflammation. We administered oral prednisolone to our patient due to the presence of lytic lesion of the bone, mild anemia and a higher sedimentation rate, which was from a separate, explained cause. Isolated tonsillar involvement in adult LCH was reported in only 2 cases in the literature. There is no standard recommendation for treatment. Our patient responded well to steroid therapy.

Recent advances in Langerhans cell histiocytosis.

The purpose of this review is to provide an updated overview of the pathogenesis and treatment of Langerhans cell histiocytosis (LCH). The pathogenesis of LCH remains obscure and the optimal treatment for LCH has not been established, although incremental progress has been made. Proinflammatory cytokines and chemokines are known to play a role in LCH, which suggests that LCH is an immune disorder. However, the oncogenic BRAF mutation is also detected in more than half of LCH patients, which suggests that LCH is a neoplastic disorder. Remaining major issues in the treatment of LCH are how to rescue patients who have risk-organ involvement but do not respond to first-line therapy, the optimal treatment for the orphan disease of multifocal adult LCH, and how to reduce and treat central nervous system-related consequences, such as central diabetes insipidus and neurodegeneration. More research is needed to better understand the pathogenesis of this disease and to resolve the treatment issues.

Langerhans cell histiocytosis: Differences and similarities in long-term outcome of paediatric and adult patients at a single institutional centre

PurposeThis study determined the frequency of clinical features, reactivations, sequelae, mortality, and overall survival (OS) and compared paediatric with adult Langerhans cell histiocytosis (LCH) patients.Materials and methodsNinety patients (60 paediatric and 30 adults) with LCH treated during 28 years were analysed retrospectively.ResultsCraniofacial lesion was the most frequent lesion at LCH presentation in children and adults. However, some differences were found. Orbital lesions were more frequent in paediatric than adult patients (P = 0.001). There was a tendency for mandible lesions to be more common in adults than the paediatric group (P = 0.0710). Mucocutaneous lesions were observed in a higher proportion in adults compared to paediatric patients (P = 0.0395). Reactivation episodes (36.8 versus 62.5%) and deaths (10.7 versus 24.0%) occurred in lower proportions in paediatric than adult patients, respectively. The probability of OS in 10 years for both groups was similar (P = 0.137).ConclusionThe OS was similar in both groups despite clinical differences between paediatric and adult patients, and higher reactivation and death rates in adults.

A Case of Adult Langerhans Cell Histiocytosis Presenting as Isolated Central Diabetes Insipidus: A Powerful Tool to Detect the Hypophyseal and Extrahypophyseal Involvement (P3.034)

A Case of Adult Langerhans Cell Histiocytosis Presenting as Isolated Central Diabetes Insipidus: A Powerful Tool to Detect the Hypophyseal and Extrahypophyseal Involvement (P3.034)

Adult Pulmonary Langerhans Cell Histiocytosis Successfully Treated With 2-Chlorodeoxyadenosine

Adult Pulmonary Langerhans Cell Histiocytosis Successfully Treated With 2-Chlorodeoxyadenosine

Langerhans cell histiocytosis misdiagnosed as liver cancer and pituitary tumor in an adult: A case report and brief review of the literature.

Langerhans cell histiocytosis (LCH) is a rare proliferative disorder in which pathological Langerhans cells accumulate in a variety of organs. LCH usually affects the bone, skin and lymph nodes of children; however, LCH occasionally affects vital organs, including the liver, spleen and pituitary gland. The present study reports a case of an adult LCH patient with marked liver damage, splenomegaly and pituitary damage treated using a new therapeutic strategy. This case was misdiagnosed as liver cancer and pituitary tumor on the basis of abdominal ultrasound, abdominal magnetic resonance imaging (MRI) and head MRI. The final diagnosis was established by identifying the proliferation of cluster of differentiation 1a-positive LCs in liver tissues. A new regimen of combined 12-week therapy of prednisolone/desmopressin/vincristine and 10 months of maintenance therapy of prednisolone/vinblastine/6-mercaptopurine improved symptoms, liver function and blood cell tests.

Successful Treatment of Adult Onset Langerhans Cell Histiocytosis with Bi-weekly Administration of Pegylated Interferon-α

© 2014 The Authors. doi: 10.2340/00015555-1807 Journal Compilation © 2014 Acta Dermato-Venereologica. ISSN 0001-5555 Langerhans cell histiocytosis (LCH) is characterised by the clonal proliferation of Langerhans cells (LC) that predominantly occurs in infants and small children, but LCH is rare in adults (1). Generally in children, local therapy would be an appropriate treatment, since patients with localised disease or disease limited to a single organ system have a good prognosis (1). However, the clinical picture of LCH in adults is not fully understood and the optimal treatment for it is still under discussion. In this report, we describe a case of adult onset LCH successfully treated with bi-weekly pegylated interferon (PEG-IFN)α2a and discuss the immunological background focusing on the tumour microenvironment immunologically.

Adult multisystem langerhans cell histiocytosis presenting with central diabetes insipidus successfully treated with chemotherapy.

We report the rare case of an adult who was diagnosed with recurrent multisystem Langerhans cell histiocytosis (LCH) involving the pituitary stalk and lung who present with central diabetes insipidus and was successfully treated with systemic steroids and chemotherapy. A 49-year-old man visited our hospital due to symptoms of polydipsia and polyuria that started 1 month prior. Two years prior to presentation, he underwent excision of right 6th and 7th rib lesions for the osteolytic lesion and chest pain, which were later confirmed to be LCH on pathology. After admission, the water deprivation test was done and the result indicated that he had central diabetes insipidus. Sella magnetic resonance imaging showed a mass on the pituitary stalk with loss of normal bright spot at the posterior lobe of the pituitary. Multiple patchy infiltrations were detected in both lung fields by computed tomography (CT). He was diagnosed with recurrent LCH and was subsequently treated with inhaled desmopressin, systemic steroids, vinblastine, and mercaptopurine. The pituitary mass disappeared after two months and both lungs were clear on chest CT after 11 months. Although clinical remission in multisystem LCH in adults is reportedly rare, our case of adult-onset multisystem LCH was treated successfully with systemic chemotherapy using prednisolone, vinblastine, and 6-mercaptopurine, which was well tolerated.

Plasma Biomarker Profiling In Langerhans Cell Histiocytosis: Risk-Stratifying The Inflammatory Storm

IntroductionDespite indistinguishable histology and the common feature of Birbeck granules in lesion biopsies, clinical presentation of patients with Langerhans Cell Histiocytosis (LCH) is highly variable, from single lesion cured by curretage, to multi-system disease requiring aggressive chemotherapy or stem cell transplant. Risk stratification for Langerhans Cell Histiocytosis has historically assigned clinical risk groups based on anatomic location and extent of LCH lesions, which is the basis for dose and duration of chemotherpy on recent Histiocyte Society trials. In this study, we test the hypothesis that distinct subgroups of patients with LCH may be identified by relative levels of circulating biomarkers. MethodsPre-therapy plasma was collected on 97 patients with LCH (82 Pediatric: 17 High-Risk, 23 Multisystem/Multifocal “Non-risk”, 42 Single Lesion “Non-risk”; 15 Adult: 5 High-Risk, 5 Multisystem/Multifocal “Non-risk”, 5 Single Lesion “Non-risk”) and 49 control subjects (32 Pediatric, 17 Adult). Quantitative levels of plasma proteins (158 analytes) was determined by multiplex analysis with Millipore MagPix kits and the Luminex plate reader. Data were analyzed with both unsupervised and supervised methodologies. ResultsConsensus clustering with non-negative matrix factorization (NMF) clusters identified three groups which were analyzed along with clinical categories. Significant clinical variables included age (adult samples clustered in NMF group 1) and LCH risk category (High-Risk LCH samples clustered in NMF group 3). Samples from patients with the BRAF-V600Emutation or relapse within 1 year did not cluster into any NMF group with signifiance. Additionally, supervised analysis identified specific molecules that were significantly differentially expressed between different clinical categories after multiple testing correction (FDR<0.10): Pediatric LCH vs Adult LCH (72 molecules significant, largest differences in MMP-3, MMP-2 and osteopontin); Pediatric Control vs Pediatric LCH (66 molecules significant, largest differences in SDF-1a, IL-20, MIP-1d, FGF-2 and sIL-4R); Pediatric Low-Risk vs Pediatric High-Risk (47 molecules significant, largest differences in sTNF-R11, sTNF-RI, I-309, sIL2Ra and osteopontin). While previous studies have analyzed expression differences of cytokines in LCH lesions and plasma, in this study the most striking differences are between control vs LCH samples are chemokine molecules. The largest differences between Low-Risk and High-Risk LCH patients include inflammatory cytokines and receptors. ConclusionsDespite mounting evidence supporting pathogenesis of LCH as a myeloid neoplasia arising from immature dendritic cell precursors, these results are consistent with exuberant chemokine and cytokine expression in patients with active LCH, supporting a potential role for inflammation in pathogenesis. This study demonstrates the feasibility of identifying novel LCH sub-groups according to plasma protein profiles with unsupervised analysis, and significant differences can be detected in protein levels between clinical risk groups. Future studies will validate the clinical utility of plasma biomarkers in diagnosis, risk-stratification and determining response to therapy. Finally, feasibility of collecting plasma compared to viable lesions makes plasma studies ideal for prospective collection and analysis in cooperative group studies. Disclosures:No relevant conflicts of interest to declare.

Rare, Isolated, Langerhans Cell Histiocytosis in a Colonic Polyp

Purpose: Langerhans cell histiocytosis (LCH) is a rare disorder of unknown pathogenesis. It is characterized by abnormal proliferation and dissemination of Langerhans cells, which are derived from the bone marrow. The disease most commonly affects the bones and the skin. Involvement of the GI tract is extremely rare. We report a case of isolated LCH in a colonic polyp. A 49-year-old woman presented with complaints of constipation, abdominal bloating, and mild change in bowel habits. She denied abdominal pain, early satiety, or weight loss. Family history was positive for colon cancer in her mother and maternal aunt. Physical exam was non-revealing. She underwent a diagnostic colonoscopy, which showed three diminutive polyps at the splenic flexure. These were removed by cold biopsy polypectomy. The rest of the colon exam was unremarkable. On histology, one of the polyps showed an ovoid collection of atypical cells within the submucosa. The cells were intermediate in size with eosinophilic cytoplasm and ovoid nuclei. The nuclei were convoluted. No cytoplasmic inclusions were identified. The atypical cells extended into the lamina propria. Immunohistochemical staining showed the cells to be strongly positive for CD1a and S100, which confirmed the diagnosis of LCH. The other polyps were hyperplastic. Subsequent extensive clinical work-up showed no evidence of disseminated LCH. Only mild eosinophilia (10.3% eosinophils) was evident. Liver function tests and urinalysis were normal. Chest x-ray showed no acute disease. CT chest showed no pulmonary lesions suggestive of Langerhans cell histiocytosis. There was no mediastinal lymphadenopathy. Review of published literature shows only a handful of cases of colonic involvement with LCH in adults. Most patients are either asymptomatic or have nonspecific GI symptoms. Polyps have usually been found incidentally on screening colonoscopy. The polyps are reported as small (less than 1 cm) and solitary, as in our patient. Only two patients have been reported to have progressed to multisystem disease with skin involvement.Figure: Langerhans cell histiocytosis in a colonic polyp.

Efficacy of radiotherapy for adult patients with Langerhans cell histiocytosis

To analyze efficacy of radiotherapy for adult patients with Langerhans cell histiocytosis (LCH). Clinical features and efficacy of radiotherapy for biopsy-proven adult patient with LCH from January 2000 to October 2012 in our hospital were retrospectively analyzed. Seventeen (11 male and 6 female) adult LCH patients with a mean age of 31 (18-56) years old were treated by irradiation, all patients presented as single-system disease. The mean duration from diagnosis to irradiation was 8.3 (0-108) months. Although 12 of 17 patients (70.6%) had short-term response to radiotherapy, all patients but one (94.1%) progressed during long-term follow-up, the mean progression-free survival (PFS) was 14 (0-131) months. Of the progressed patients, one relapsed in situ, the remaining 15 patients progressed outside the irradiated region. Thirteen patients (76.5%) eventually progressed to multisystem disease. Though radiotherapy for LCH in adults produced a high short-term response up to 70.6%, most of patients eventually progressed in situ or outside the irradiation region during long-term follow-up.

Langerhans cell histiocytosis in cervical node in an adult female - a case report

A case of Langerhans Cell Histiocytosis (LCH) in a 58 year old woman who presented with bilateral cervical adenopathy without any other complaints is reported. Clinical examination did not reveal any other positive finding except the adenopathy. Histopathological examination confirmed the node to be Langerhans cell histiocytosis. In conclusion, LCH is a rare disease with varied clinical presentation, including cervical adenopathy. Diagnosis should be confirmed by histopathological examination of biopsy specimen. Observation may be an effective management strategy in cases of adult LCH with cervical adenopathy as the only symptom, due to its possible spontaneous regression. (Med J Indones. 2013;22:114-6) Keywords: Langerhans cell histiocytosis

Langerhans cell histiocytosis in adult

Langerhans cell histiocytosis (LCH) is a very rare benign disease.It belongs to a class of histologically non-malignant dendritic cell disorder showing atypical clonal proliferation of immature Langerhans cell histiocytes with dissemination to various tissues. This is a case report of a 40 year old woman with a past history of eosinophilic granuloma involving multiple skeletal systems. She was treated in our institute with surgery for left parietal bone lesion in 2006 and with chemotherapy for multiple skeletal involvements in 2007. She presented again on 2010 with new lesions in oral cavity, left parotid gland, bilateral cervical lymphnodes, inguinal lymphnodes and skeletal involvement other than the previous sites of 2006. She was treated for this reactivation of the disease as per LCH-III treatment protocol considering it as a new one. This case is being reported due to rarity of LCH in adults and its rare presentation in parotid gland (only 3 cases have been reported in literature). This is also to report the reactivation of LCH after four years with presentation at different sites and the management we did.

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

Langerhans Cell Histiocytosis (LCH) is an orphan disease of clonal dendritic cells which may affect any organ of the body. Most of the knowledge about the diagnosis and therapy is based on pedriatic studies. Adult LCH patients are often evaluated by physicians who focus on only the most obviously affected organ without sufficient evaluation of other systems, resulting in patients being underdiagnosed and/or incompletely staged. Furthermore they may be treated with pediatric-based therapies which are less effective and sometimes more toxic for adults. The published literature on adult LCH cases lacks a comprehensive discussion on the differences between pediatric and adult patients and there are no recommendations for evaluation and comparative therapies. In order to fill this void, a number of experts in this field cooperated to develop the first recommendations for management of adult patients with LCH. Key questions were selected according to the clinical relevance focusing on diagnostic work up, therapy, and follow up. Based on the available literature up to December 2012, recommendations were established, drafts were commented by the entire group, and redrafted by the executive editor. The quality of evidence of the recommendations is predominantly attributed to the level of expert opinion. Final agreement was by consensus.

Management of adult Langerhans cell histiocytosis based on the characteristic clinical features

Management of adult Langerhans cell histiocytosis based on the characteristic clinical features

Therapeutic outcome of multifocal Langerhans cell histiocytosis in adults treated with the Special C regimen formulated by the Japan LCH Study Group

Little information is available regarding effective systemic therapies for adult Langerhans cell histiocytosis (LCH). The Japan LCH Study Group has formulated an ambulatory treatment regimen for adult patients with LCH. In total, 14 patients (median age 43years, range 20-70years) with multifocal LCH with biopsy-confirmed histology were enrolled. None had received cytoreductive agents for LCH previously. Four had single system (SS) and ten had multi system (MS) disease. All were treated with the Special C regimen, which consists of vinblastine/prednisolone and methotrexate with daily 6-mercaptopurine for 36weeks. At the end of the therapeutic regimen, all SS patients achieved no active disease (NAD), and six of the ten MS patients showed a response (NAD in two, partial response in four). At the last follow-up (median 34months), 11 patients were alive (NAD in eight and active disease in three). Of the three deceased, one died of hemorrhage during the Special C treatment, and two of infections during subsequent therapy. Although this study is limited by the small sample size, this ambulatory regimen shows signs of efficacy for adult LCH. This was particularly evident for patients with multifocal SS disease, but half of those with MS disease also benefited.

P114 Pulmonary Function Progression in Langerhans Cell Histiocytosis

Langerhans Cell Histiocytosis (LCH) is a rare, dendritic cell disorder commonly involving the lungs either alone, (PLCH) or as part of multi-system disease (MSLCH). The natural history is variable, ranging...

Clinicopathologic analysis of Langerhans cell histiocytosis in adults

To explore the clinical features, pathomorphology, immunohistochemical characteristics and prognosis of Langerhans cell histiocytosis (LCH) in adults. Twenty-three cases of adult LCH were retrieved from Ningbo Diagnostic Pathology Center during the period from January 2005 to December 2011. And their clinical presentation, pathomorphology and immunohistochemical characteristics were analyzed. The mean age of patients was 37.2 years (range: 20 - 58). The male-to-female ratio was 1.6:1. Of 23 LCH patients, 26 lesions were found including 14 bone tissue lesions (53.8%), followed by 4 lymph node lesions and 4 skin lesions (both 15.4%), as well as 1 soft tissue, liver, parotid and buccal lesion respectively (all 3.8%). Clinically, uni-system and unifocal disease was predominant (19 cases, 82.6%), followed by uni-system and multifocal disease (1 case, 4.3%), multi-system disease (3 cases, 13.0%). Histologically, all cases of LCH revealed diffused distribution of Langerhans cells, accompanied by a variable number of eosinophils, lymphocytes, neutrophils and multinucleated giant cells. Immunohistochemically, the expression of CD1a, Langerin, S-100 protein and CD68 was 100% (23/23), 100% (20/20), 95.6% (22/23) and 90.5% (19/21) respectively. All lesions were treated by surgical therapy. Sixteen patients were available for follow-up examination and 14 patients survived. The 3 and 5-year cumulative survival rates were 92.9% and 79.6% respectively. LCH of adults occurs predominantly in bone and presents mainly as uni-system or unifocal defects. Surgical excision is generally effective and the prognosis is fair.