MACOP-B regimen in the treatment of adult Langerhans cell histiocytosis: experience on seven patients

Case Report: Langerhans cell histiocytosis involving the cervical spine in an adult patient

Langerhans Cell Histiocytosis (LCH) is a typically benign disorder that affects infants predominately, with adult occurrence being uncommon. We discuss the case of a 22-year-old guy who visited our clinic complaining of three months of acute nape pain and upper limb radiculopathy. Notably, the patient had no history of trauma, fall injuries, or tuberculosis. Radiological tests identified a single osteolytic lesion within the C3 vertebral body. The lesion was removed, an anterior C3 corpectomy and discectomy were performed, and the patient's spine was reconstructed with a titanium cage and plating. The patient's nape discomfort and radiculopathy vanished almost instantly after surgery. A definitive diagnosis of LCH was confirmed through histological examination. This case report illustrates the unusual and uncommon occurrence of LCH at the C3 vertebral body, for which fusion surgery was the only viable therapeutic option. The patient's recovery from radiating pain following the surgical procedure demonstrates the effectiveness of the intervention. LCH in the cervical spine is rather rare, but it is nevertheless important to be aware of the possibility of developing it.

Clinical and prognostic features of Langerhans cell histiocytosis in adults

Langerhans cell histiocytosis (LCH) is a rare disease characterized by clonal expansion of CD1a+ CD207+ myeloid dendritic cells. The features of LCH are mainly described in children and remain poorly defined in adults; therefore, we conducted a nationwide survey to collect clinical data from 148 adult patients with LCH. The median age at diagnosis was 46.5 (range: 20-87) years with male predominance (60.8%). Among the 86 patients with detailed treatment information, 40 (46.5%) had single system LCH, whereas 46 (53.5%) had multisystem LCH. Moreover, 19 patients (22.1%) had an additional malignancy. BRAF V600E in plasma cell-free DNA was associated with a low overall survival (OS) rate and the risk of the pituitary gland and central nervous system involvement. At a median follow-up of 55 months from diagnosis, six patients (7.0%) had died, and the four patients with LCH-related death did not respond to initial chemotherapy. The OS probability at 5 years post-diagnosis was 90.6% (95% confidence interval: 79.8-95.8). Multivariate analysis showed that patients aged ≥60 years at diagnosis had a relatively poor prognosis. The probability of event-free survival at 5 years was 52.1% (95% confidence interval: 36.6-65.5), with 57 patients requiring chemotherapy. In this study, we first revealed the high rate of relapse after chemotherapy and mortality of poor responders in adults as well as children. Therefore, prospective therapeutic studies of adults with LCH using targeted therapies are needed to improve outcomes in adults with LCH.

Update on Pulmonary Langerhans Cell Histiocytosis

Pulmonary Langerhans cell (LC) histiocytosis (PLCH) has unknown cause and is a rare neoplastic disorder characterized by the infiltration of lungs and various organs by bone marrow-derived Langerhans cells with an accompanying strong inflammatory response. These cells carry somatic mutations of BRAF gene and/or NRAS, KRAS, and MAP2K1 genes, which cause activation of the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) signaling pathway. PLCH occurs predominantly in young smokers, without gender predominance. Lungs might be involved as an isolated organ or as part of a multiorgan disease. High-resolution computed chest tomography plays an outstanding role in PLCH diagnosis. The typical radiological picture of PLCH is the presence of small intralobular nodules, “tree in bud” opacities, cavitated nodules, and thin- and thick-walled cysts, frequently confluent. Histological examination of the lesion and demonstration of characteristic eosinophilic granulomas with the presence of LCs that display antigen CD1a or CD207 in immunohistochemistry are required for definite diagnosis. Smoking cessation is the most important recommendation for PLCH patients, but treatment of progressive PLCH and multisystem disease is based on chemotherapy. Recently, new targeted therapies have been implemented.

Highlights of the Management of Adult Histiocytic Disorders: Langerhans Cell Histiocytosis, Erdheim-Chester Disease, Rosai-Dorfman Disease, and Hemophagocytic Lymphohistiocytosis

Histiocytic disorders are an exceptionally rare group of diseases with diverse manifestations and a paucity of approved treatments, thereby leading to various challenges in their diagnosis and management. With the discovery of novel molecular targets and the incorporation of targeted agents in the management of various adult histiocytic disorders, their management has become increasingly complex. In an attempt to improve the understanding of the clinical features and management of common adult histiocytic disorders (Langerhans cell histiocytosis, Erdheim-Chester disease, Rosai-Dorfman disease, and hemophagocytic lymphohistiocytosis), we created this document based on existing literature and expert opinion.

Langerhans Cell Histiocytosis in the Adult Lumbar Spine - A Case Report and Literature Review

Introduction:

Langerhans cell histiocytosis (LCH) in spine is a benign disorder that mainly affects children and is rare in adults. The treatment of LCH in adults is still controversial. The literature is drought with reports regarding management of LCH in adults with pathological fracture. We report a case of LCH at L5 vertebra in an adult patient treated with posterior stabilization, decompression, and anterior corpectomy and reconstruction.

Case Presentation:

A 30-year-old manual laborer working in Middle East, presented to us with severe pain in the lower back (VAS-8) with the right lower limb radiculopathy for 6 months. Radiological investigations revealed to have a solitary osteolytic lesion with pathological fracture at L5 vertebral body. MRI showed hyperintense lesion in T2 sagittal images and hypointense in T1 sagittal images in L5 vertebral body. PET scan showed metabolically active lesion involving L5 vertebra body and right ischium. CT-guided biopsy from L5 vertebral body was performed, but was inconclusive. The patient underwent surgical management in the form of posterior stabilization L4-S1 and transpedicular biopsy. The sample was sent for frozen section and confirmed the presence of neoplasia but did not provide sufficient information about the nature of pathology. Intraoperatively, the decision was made to do anterior excision biopsy, corpectomy, and reconstruction with titanium mesh cage filled with cement. The precise diagnosis of LCH was established on histopathological examination and confirmed with immunohistochemistry positivity for CD1a and S100. The patient had immediate relief of his back pain and radicular pain. He was able to resume his daily activities at 1 month after the surgery. At 2-year follow-up patient was asymptomatic and no local recurrence was noticed.

Conclusion:

Surgical excisionfor LCH in adults should be considered in patients with refractory low back pain with pathological fracture, neurological deficits, or spinal instability.

Clinical features and outcomes of adult Langerhans cell histiocytosis: a single-center experience

Langerhans cell histiocytosis (LCH) is a clonally expanding neoplasm characterized by the accumulation of CD1a + CD207 + myeloid dendritic cells. As LCH is a rare disease and is presumed to mainly affect children, the clinical features and treatment outcomes of adult LCH have been poorly documented. We retrospectively reviewed 53 adult patients with LCH who were referred to the Institute of Medical Science, the University of Tokyo from 2005 to 2018. The median age at diagnosis was 42 years with a slight female predominance (57%). The time between onset and diagnosis varied among patients (median, 8 months; range, 0-144 months). In total, 40% of the patients had single organ involvement and 60% had multiple organ involvement. Overall, the most frequently affected organ was bone (62%), followed by the central nervous system (34%), and the lung (28%). Twenty-six patients required systemic treatment, and 25 patients underwent the Special C regimen. Twenty patients (80%) who underwent Special C regimen showed a partial response or better with favorable toxicity. All but one patient is still alive. Median progression-free survival has not been reached despite a median follow-up of 35.5 months. Immunohistochemistry revealed that 39% of patients were positive for BRAF-V600E, which was a lower proportion than in previous reports from North America and Europe.

Adult Langerhans cell histiocytosis and immunomodulatory drugs: Review and analysis of thirty-four case reports

Langerhans cell histiocytosis (LCH) is a rare neoplastic disease in dendritic cells. LCH is classified as either a single-system (SS) or multisystem (MS) disease. There is not a standard first-line treatment for LCH in adults. We analyzed the efficacy and safety of immunomodulatory drugs (IMiDs) by searching PubMed/MEDLINE for case reports previously published. The clinical response (nonactive disease or active disease that regressed) was 94% in SS and 53% in MS. IMiDs should only be considered for adults with cutaneous SS involvement; in MS, they should be used only for patients not eligible for more aggressive treatments.

Adult Langerhans cell histiocytosis with pulmonary and colorectoanal involvement: a case report

BACKGROUND

Langerhans cell histiocytosis is a rare systemic disease characterized by the abnormal overproduction of histiocytes that tend to infiltrate single or multiple organ systems leading to significant tissue damage. It mainly affects - by order of decreasing frequency - the bone, the skin, the lymph nodes, the liver, and lungs. Gastrointestinal tract involvement is extremely rare in adults.

CASE PRESENTATION

We describe the case of a 32-year-old Middle Eastern man with Langerhans cell histiocytosis involving his lungs and the colorectoanal part of his gastrointestinal tract, with complete resolution of gastrointestinal tract lesions following a non-standardized chemotherapy regimen.

CONCLUSIONS

Gastrointestinal tract lesions are a rare manifestation of Langerhans cell histiocytosis, especially when associated with extraintestinal involvement, such as the lungs. Chemotherapy protocols have not been well established for the treatment of the disease. The clinical impact of the effective chemotherapy regimen used to treat this uncommon presentation of Langerhans cell histiocytosis will be viewed in this case report.

Vinblastine chemotherapy in adult patients with langerhans cell histiocytosis: a multicenter retrospective study

Background

Vinblastine is the standard treatment for children with Langerhans cell histiocytosis (LCH). Whether this treatment could be extended to adults with LCH is questionable. This retrospective multicenter study included 35 adult patients (median age 33 years; 23 men; 80% with multisystem LCH) who were treated with vinblastine + steroids as a first-line chemotherapy and followed for a median time of 83 months. The objectives were to determine the overall response rate (based on the Histiocyte Society criteria), disease reactivation rate, toxicity, permanent consequences, and survival rate corresponding to this treatment. The lung involvement outcome was based on serial lung function tests. The distribution of right-censored end points was estimated by the Kaplan-Meier method. Univariate Cox model with time-fixed and time-varying covariates was used for the predictive analysis of reactivation in the responders. Univariate analyses of risk factors for neurotoxicity were based on nonparametric Wilcoxon rank sum tests and exact Fisher tests.

Results

The median duration of the first course of vinblastine was 7.6 months, with a median cumulative dose of 160 mg [IQR 120–212]. Seventy percent of the patients were responders at the end of this treatment. Subsequently, LCH reactivation occurred with a 5-year cumulative incidence of 40%. During the study, 27 reactivations were observed in 17 patients, and half of these episodes were retreated with vinblastine. At the end of the last vinblastine treatment, 70% of the patients were responders. None of the patients with impaired lung function improved. No grade 3–4 peripheral neuropathy was observed. At the final vinblastine treatment, permanent LCH consequences, primarily pituitary stalk involvement, were present in 15 (43%) patients, and all were present at the time of vinblastine initiation. The 10-year survival rate was 86.2% (95CI, 71.8–100%), and the 2 patients who died from LCH had risk organ localizations.

Conclusions

Vinblastine is an effective and well-tolerated first-line treatment for adult LCH except in patients with lung involvement and impaired lung function. However, a significant portion of patients experienced LCH reactivation during long-term follow up. As in childhood LCH, the presence of risk organ involvement has a negative impact on patient prognosis.

A phase IIa study of afuresertib, an oral pan-AKT inhibitor, in patients with Langerhans cell histiocytosis

BACKGROUND

Langerhans cell histiocytosis (LCH) is a clonal neoplasm characterized by widely varied clinical presentations, including multisystem involvement and systemic inflammatory symptoms. The AKT pathway is relevant to survival and proliferation of dendritic cells, and is also often upregulated in hematopoietic malignancies. A clinical response in an adult patient with LCH participating in the first-in-human trial of afuresertib prompted this prospective trial.

PROCEDURE

The population in the current study included treatment-naïve (n = 7) and recurrent/refractory patients with LCH (n = 10), who received oral afuresertib (125 mg). The majority of patients were treated for > 24 weeks, with four patients receiving treatment for > 48 weeks.

RESULTS

Pharmacokinetic analysis showed similar exposures in previously reported patients with other hematologic malignancies. Primary drug-related toxicities included Grade 1/2 nausea, diarrhea, dyspepsia, and vomiting. Grade 3 toxicities included fatigue, diarrhea, and pain (one of each). Another severe adverse event involved soft tissue necrosis. The overall response rate in evaluable subjects was 33% in treatment-naïve patients and 28% in patients with recurrent/refractory disease, which did not meet the predefined Bayesian criteria for efficacy.

CONCLUSION

Afuresertib has clinical activity in some patients with newly diagnosed and advanced LCH.

Treatment of Langerhans cell histiocytosis: role of BRAF/MAPK inhibition

Langerhans cell histiocytosis (LCH) is a clonally derived neoplasm with a highly variable clinical course. Although LCH was once considered a disorder of immune regulation, the identification of activating mutations in the proto-oncogene BRAF-V600E in ∼50%-60% of cases and MEK and ERK phosphorylation in 100% of examined cases, has changed the definition of LCH to a dendritic cell neoplasm with a strong inflammatory component. Current international LCH trials are focused on further improving the outcome of high-risk multisystem LCH patients, by decreasing the reactivation rate, optimizing early salvage regimens, and preventing late sequelae. Anecdotal responses to vemurafenib, a BRAF-V600E inhibitor, have been reported in a few cases of LCH and Erdheim–Chester disease. However, the development of resistance, as well as the potential risks of cutaneous and pancreatic cancers in patients with BRAF-V600E-mutated melanoma treated with single inhibitors, suggest the need for prospective trials with BRAF inhibitors, alone or in combination with other inhibitors of this pathway, for patients with refractory or multiply-relapsed LCH. The recent discovery of somatic mutations in ARAF and in MAP2K1, which lead to activation of the RAS-RAF-MEK –ERK pathway in the setting of wild-type BRAF, as well as the finding that activating mutation in MAP2K1 are relatively insensitive to MEK inhibitors, suggest that a more detailed understanding of this pathway in LCH may be necessary for the development of more effective targeted therapies.

Treatment of Langerhans cell histiocytosis: role of BRAF/MAPK inhibition

Langerhans cell histiocytosis (LCH) is a clonally derived neoplasm with a highly variable clinical course. Although LCH was once considered a disorder of immune regulation, the identification of activating mutations in the proto-oncogene BRAF-V600E in ∼50%-60% of cases and MEK and ERK phosphorylation in 100% of examined cases, has changed the definition of LCH to a dendritic cell neoplasm with a strong inflammatory component. Current international LCH trials are focused on further improving the outcome of high-risk multisystem LCH patients, by decreasing the reactivation rate, optimizing early salvage regimens, and preventing late sequelae. Anecdotal responses to vemurafenib, a BRAF-V600E inhibitor, have been reported in a few cases of LCH and Erdheim–Chester disease. However, the development of resistance, as well as the potential risks of cutaneous and pancreatic cancers in patients with BRAF-V600E-mutated melanoma treated with single inhibitors, suggest the need for prospective trials with BRAF inhibitors, alone or in combination with other inhibitors of this pathway, for patients with refractory or multiply-relapsed LCH. The recent discovery of somatic mutations in ARAF and in MAP2K1, which lead to activation of the RAS-RAF-MEK –ERK pathway in the setting of wild-type BRAF, as well as the finding that activating mutation in MAP2K1 are relatively insensitive to MEK inhibitors, suggest that a more detailed understanding of this pathway in LCH may be necessary for the development of more effective targeted therapies.

High efficacy of the MACOP-B regimen in the treatment of adult Langerhans cell histiocytosis, a 20 year experience

BACKGROUND

Adult Langerhans cell histiocytosis (LCH) is an orphan disease. Chemotherapy is usually reserved to patients presenting with single system multifocal (SS-m) or multisystem (MS) disease but due to the lack of randomized studies no standard first line therapy has been defined yet. Pediatric regimens based on the vinblastine/prednisone backbone are not well tolerated in adults and probably less effective. We previously demonstrated high efficacy of the dose dense polichemotherapy regimen MACOP-B in 7 adult patients with SS-m or MS-LCH, in terms of high response rate and durable responses. Here we report an update of these data with the purpose of evaluating the long term efficacy of MACOP-B in adult LCH.

METHODS

Clinical data of all adult LCH patients (n = 17) diagnosed and treated at our Institution during the past 20-year period were retrospectively reviewed.

RESULTS

A total of 11 patients (6 with SS-m and 5 with MS-LCH) were treated with MACOP-B from 1995 to 2014. The overall response rate was confirmed to be 100 %, with a complete response of 73 % and a partial response rate of 27 %. Overall progression free survival was 64 %, and disease free survival after achievement of initial CR was 87 %. Overall survival rate was 82 % after 6.7 years of median follow-up.

CONCLUSIONS

These data confirm high activity of MACOP-B in adult LCH, indicating that a substantial fraction of patients achieve long lasting responses and can be cured with this therapeutic approach.

Transplantation in rare lymphoproliferative and histiocytic disorders

BACKGROUND

Some uncommon lymphoproliferative and histiocytic disorders may present with an aggressive course and require hematopoietic stem cell transplantation (HSCT) as part of the therapeutic approach.

METHODS

Published research on the use of HSCT for the treatment of these disorders was reviewed and summarized.

RESULTS

Allogeneic HSCT may be indicated in patients with blastic plasmacytoid dendritic cell neoplasia, familial or secondary recurrent hemophagocytic lymphohistiocytosis, and resistant Langerhans cell histiocytosis. Autologous HSCT may be considered in patients with Castleman disease resistant to treatment. No role has been established for the use of HSCT for dendritic cell sarcoma.

CONCLUSIONS

HSCT has an evolving role in the treatment of select aggressive lymphoproliferative and histiocytic disorders.

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.

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

To find out the most appropriate management, clinical features of 18 cases of adult multisystem langerhans cell histiocytosis (LCH) have been analyzed. The patients comprising of 9 males and 9 females were median age of 36 years, ranging from 18-53 years at diagnosis. Regarding the initial symptoms, 7 patients (2 males and 5 females) showed central diabetes insipidus (CDI) and other endocrine symptoms with thickened pituitary stalk or a mass at the hypothalamic region. Additional 2 patients initiated the disease with CDI with no immediate diagnosis. In the remaining patients, the disease begun with single (n = 3) or multiple (n = 1) spinal bone lesion(s) in 4 patients (all males), with multiple bone lesions in 3 patients (1 male and 2 females), with single skull lesion in one female patient and with ambiguous symptoms including hypothyroidism in the remaining one male patient. We also recognized the correlation between pregnancy/childbirth and LCH in 4 patients. In terms of treatment, 9 patients received systemic immuno-chemotherapy alone, of which the majority received vinblastine-based chemotherapy while 4 received 2-chlorodeoxyadenosine. Five had a combination of immuno-chemotherapy with surgical resection or radiotherapy, 2 had immunotherapy alone, 2 had surgical resection followed by observation alone to date. Three patients received hematopoietic stem cell transplantation after extensive chemotherapy. In terms of outcome, 15 patients are alive (9 with active disease, 6 without active disease), with a median of 66 mo (range 17-166 mo), two died of disease while the remaining 1 lost to follow-up. Based on these results, we think that early diagnosis and rapid introduction of appropriate treatment are essential, in order to overcome the problems relevant to adult LCH.

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.

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 43 years, range 20-70 years) 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 36 weeks. 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 34 months), 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.

Recurrent adult-onset hypophyseal Langerhans cell histiocytosis after radiotherapy: a case report

Introduction

Langerhans cell histiocytosis is a rare disease within the adult population, with very few cases reported as solitary hypophyseal lesions in adults. Of the reported cases, most have been treated successfully with surgery, radiotherapy, and/or chemotherapy. Radiotherapy has been thought to be curative at the relatively low dose of 20Gy. Here we report a case of recurrent hypophyseal Langerhans cell histiocytosis 9 months after radiotherapy with an interval period of symptomatic and radiographic response to therapy.

Case presentation

A 50-year-old Caucasian woman who had headaches, memory difficulties, and diabetes insipidus was found to have a 2.5cm suprasellar mass. Langerhans cell histiocytosis was diagnosed following stereotactic brain biopsy. Further workup revealed no other lesions. Initial radiation treatment succeeded in shrinking the tumor and relieving clinical symptoms temporarily; however, growth and recurrence of clinical symptoms was noted at 9 months. Re-irradiation was well tolerated and the patient had no acute side effects.

Conclusion

Isolated hypophyseal involvement by Langerhans cell histiocytosis in adults is a unique presentation of a rare disease. Although radiotherapy doses as low as 20Gy have been reported to offer control, this case demonstrates that higher doses may be warranted to ensure tumor control. With modern imaging and radiotherapy techniques higher doses should offer little increased more durable risk to surrounding critical structures.

Optimal therapy for adults with Langerhans cell histiocytosis bone lesions

Background

There is little data on treatment of Langerhans cell histiocytosis (LCH) in adults. Available data is on small numbers of patients with short follow-up times and no comparison of results from different treatment regimens. We analyzed the responses of adult LCH patients with bone lesions to three primary chemotherapy treatments to define the optimal one.

Methods and Findings

Fifty-eight adult patients with bone lesions, either as a solitary site or as a component of multisystem disease, were analyzed for disease location and response to surgery, curettage, steroids, radiation, vinblastine/prednisone, 2-Chlorodeoxyadenosine (2-CdA), or cytosine arabinoside (ARA-C). The mean age of patients was 32 years, with equal gender distribution. Twenty-nine patients had 1 lesion; 16, 2 lesions; 5, 3 lesions; and 8 had 4 or more. Most bone lesions were in the skull, spine, or jaw. Chemotherapy, surgery, curettage, or radiation, but not steroids alone, achieved improvement or resolution of lesions in a majority of patients. Comparison of the three chemotherapy regimens revealed 84% of patients treated with vinblastine/prednisone either did not respond or relapsed within a year, whereas 59% of patients treated with 2-CdA and 21% treated with ARA-C failed. Toxicity was worse with the vinblastine/prednisone group as 75% had grade 3–4 neuropathy. Grade 3–4 cytopenias occurred in 37% of the 2-CdA -treated patients and 20% of the ARA-C-treated patients. The major limitation of this study is it is retrospective and not a clinical trial.

Conclusions

ARA-C is an effective and minimally toxic treatment for LCH bone lesions in adults. In contrast, vinblastine/prednisone results in poor overall responses and excessive toxicity.

Langerhans cell histiocytosis: 40 years' experience

OBJECTIVES

Our study analyzes 40 years' experience with pediatric Langerhans cell histiocytosis patients.

MATERIALS AND METHODS

Between June 1968 and December 2009, 121 patients (79 males, 42 females; median age 4.13 y) were diagnosed at our center (74% monosystemic disease; 26% multisystemic), treated according to current protocols. We evaluated the response, the survival, and the neuroendocrinological sequelae.

RESULTS

Overall survival (OS) for all patients was 93% at 10 years from diagnosis, event-free survival (EFS) 77%. OS for patients younger than 2 years and older than or equal to 2 years was 82% and 97% (P = 0.003); EFS 48% and 87% (P = 0.001). OS for patients diagnosed before and after April 1, 1991 was 84% and 98% (P = 0.007), EFS 66% and 85% (P = 0.03). OS for monosystemic and multisystemic disease was 100% and 71% (P < 0.001); EFS 88% and 45% (P < 0.001). OS for "risk" patients (involvement of bone marrow, spleen, liver, lungs) and "low-risk" patients was 50% and 94% (P = 0.007), EFS 37% and 54% (P = 0.06). Fourteen patients developed diabetes insipidus, 7 patients growth hormone deficiency, 2 hypothyroidism, and 1 neurodegeneration.

CONCLUSIONS

Our study confirms improvement of pathogenetic knowledge and treatment over the last 20 years. Age at diagnosis older than or equal to 2 years and standardized treatment are associated with improved prognoses. Multisystemic involvement, especially with "risk" organs seem to be correlated to a worse outcome.

Measuring diffuse metabolic activity on FDG-PET/CT: new method for evaluating Langerhans cell histiocytosis activity in pulmonary parenchyma

INTRODUCTION

Pulmonary Langerhans cell histiocytosis (PLCH) is a rare cause of interstitial lung disease characterized by formation of nodules in the active phase of the disease that evolve into nonactive cystic lesions later on. To evaluate PLCH activity in patients, we developed a new method for measuring diffuse metabolic activity on fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) using a lung-to-liver activity ratio.

MATERIAL AND METHODS

We retrospectively studied a series of 4 FDG-PET and 23 FDG-PET/CT scans from 7 patients with PLCH and analyzed a sample of 100 randomly chosen FDG-PET/CT studies free from any known lung or hepatic diseases. Maximum standardized uptake value (SUVmax) in a spherical volume (6-8 cm in diameter) in the right lung was put into relation with SUVmax in a spherical volume (9-10 cm in diameter) in the reference liver parenchyma to set up the SUVmaxPULMO/SUVmaxHEPAR index. The index values were compared to the disease course in each patient.

RESULTS

In patients with PLCH, a close correlation between the index value and the disease course was found in all seven subjects, where the increasing index values indicated disease activity, while decreasing index values were observed after therapy administration. In the group of 100 healthy control subjects, we found index values lower than 0.3 in 80% and lower than 0.4 in 96% [range: 0.14-0.43; 0.24±0.07 (100)].

CONCLUSION

Measuring SUVmaxPULMO/SUVmaxHEPAR values and their time-trend monitoring represent simple, noninvasive screening tools allowing an early diagnosis and treatment response follow-up assessment in patients with PLCH.

Langerhans cell histiocytosis: old disease new treatment

Langerhans cell histiocytosis (LCH) has been previously thought of as a rare illness, but is now increasingly diagnosed as a result of the more intensive investigations of patients with cystic pulmonary disease. In recent years, treatments developed from our new understanding of the molecular biology of malignant disease have been applied to patients with LCH, and responses seen. In this review, we describe the origins, presentation and modern treatment of LCH, showing that there is new hope for patients with this condition.

Successful treatment of adult onset Langerhans cell histiocytosis with multi-drug combination therapy

Adult onset Langerhans cell histiocytosis (LCH) is a rare disorder. Its clinical features have been well described in children, however remain poorly defined in adults. Optimal treatment strategy is still under debate. We have encountered two cases of adult onset LCH, which obtained a durable disease control by combination chemotherapy using prednisone, vinblastine and 6-mercaptopurine. Herein, we report their clinical features together with a review of the current literature.