2-Chlorodeoxyadenosine therapy for disseminated Langerhans cell histiocytosis

Pulmonary Langerhans cell histiocytosis presenting as an uncommon mass in the lung: A rare case report and literature review

A comprehensive diagnostic approach, including immunohistochemistry, is crucial for confirming pulmonary Langerhans cell histiocytosis in adults. Individualized treatment with dynamically adjusted chemotherapy based on therapeutic response leads to significant absorption of lesions and symptom alleviation. Regular follow-up and timely treatment adjustments according to the patient's condition are essential in managing this rare disease.

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.

Ultra-rare cystic disease

Diffuse cystic lung diseases include a group of heterogeneous disorders characterised by the presence of cysts within the lung parenchyma, sometimes showing a characteristic computed tomography scan pattern that allows diagnosis. The pathogenetic mechanisms underlying cyst formation in the lung are still not clear and a number of hypotheses have been postulated according to the different aetiologies: ball-valve effect, ischaemic dilatation of small airways and alveoli related to infiltration and obstruction of small vessels and capillaries that supply the terminal bronchioles and connective tissue degradation by matrix metalloproteases. A wide number of lung cyst diseases have been classified into six diagnostic groups according to the aetiology: neoplastic, congenital/genetic, lymphoproliferative, infective, associated with interstitial lung diseases, and other causes. This article focuses on lymphangioleiomyomatosis, pulmonary Langerhans cell histiocytosis and Erdheim–Chester disease, Birt–Hogg–Dubé, follicular bronchiolitis and lymphocytic interstitial pneumonia, light-chain deposition disease and amyloidosis, congenital lung disease associated with aberrant lung development and growth, and cystic lung disease associated with neoplastic lesion. These cystic diseases are epidemiologically considered as ultra-rare conditions as they affect fewer than one individual per 50 000 or fewer than 20 individuals per million. Despite the rarity of this group of disorders, the increasing use of high-resolution computed tomography has improved the diagnostic yield, even in asymptomatic patients allowing prompt and correct therapy and management without the need for a biopsy.

Diffuse cystic lung diseases show a characteristic CT scan pattern that often allows for diagnosis, even in asymptomatic patients, allowing prompt correct therapy and management without the needing of a biopsyhttps://bit.ly/2wIUKet

Long-term efficacy and safety of 2CdA (cladribine) in extra-pulmonary adult-onset Langerhans cell histiocytosis: analysis of 23 cases from the French Histiocytosis Group and systematic literature review

Langerhans cell histiocytosis (LCH) is a rare protean disease that usually affects children. Few data are available for management of adult-onset cases. A complete picture of the efficacy and safety of 2CdA (2-chlorodeoxyadenosine, cladribine) is lacking. We report a retrospective multicentre study of 23 adult LCH (a-LCH) patients who received single-agent 2CdA and a systematic literature review. All had previously received systemic therapy (vinblastine, n = 19). Response to 2CdA was evaluable in 22 cases. Overall response rate (ORR) was 91%. Complete response (CR) occurred in 11 cases (50%). Nine patients (39%) developed grade 3-4 neutropenia and/or severe infection. A literature review yielded 48 additional cases. A pooled analysis confirmed our findings (ORR: 88%, CR: 49%). CRs were rare with cumulative dose <50 mg/m² . Disease progression rates were 20% and 30% at two and five years, respectively. Partial response (PR) to 2CdA was predictive of disease progression. Among eight re-treated patients, five went into CR, two in PR, and one died. Single-agent 2CdA is effective in reactivated a-LCH, including at intermediate doses. Toxicity, significant but acceptable, warrants infectious prophylaxis. Complete responders may enter prolonged remission. Further studies are needed to determine 2CdA sequencing with other agents (vinblastine, cytarabine).

A Very Rare Case of Right Insular Lobe Langerhans Cell Histiocytosis (CD1a+) Mimicking Glioblastoma Multiforme in a Young Adult

BACKGROUND

Langerhans cell histiocytosis (LCH) is a multisystemic dendritic cell proliferation that is relatively uncommon in adults. Central nervous system LCH outside the pituitary gland is even more uncommon.

CASE DESCRIPTION

We report the case of a 42-year-old man who had complained of right-side hemicranial pain and left arm minor paresis. The symptoms were due to a right insular lobe heterogeneous-enhancing lesion associated with extensive vasogenic edema. The first diagnostic impression suggested glioblastoma multiforme or localized metastasis. The thoracic, abdominal, pelvic computed tomography scan only detected small upper lung inactive nodules suggesting silent focal LCH. A very hard lesion was almost completely removed through a pterional craniotomy approach, with no fluorescence after aminolevulinic acid infusion. The intraoperative biopsy findings ruled out glioma but could not confirm lymphoma. The definitive cerebral biopsy findings showed lymphocytes and histiocytes (CD1a⁺, S-1001⁺), with a diagnosis of intracerebral parenchymal LCH. Fractioned radiotherapy resulted in clinical and radiological remission.

CONCLUSIONS

The present case is so rare it should not be used as a guide. We probably will never see a single intraparenchymal supratentorial central nervous system LCH lesion. However, we hope our report will help colleagues in the future with the thought process.

Current understanding and management of pulmonary Langerhans cell histiocytosis

Pulmonary Langerhans cell histiocytosis (PLCH) is a diffuse lung disease that usually affects young adult smokers. PLCH affects different lung compartments; bronchiolar, interstitial and pulmonary vascular dysfunction may coexist to varying extents, resulting in diverse phenotypes. Analyses of PLCH tissues have identified activating mutations of specific mitogen-activated protein kinases (BRAF^V600E and others). The current consensus is that PLCH represents a myeloid neoplasm with inflammatory properties: the myeloid tumour cells exhibit surface CD1a expression and up to 50% of the cells harbour activating BRAF or other MAPK mutations. PLCH may be associated with multisystem disease. The detection of disease outside of the thorax is facilitated by whole body positron emission tomography. The natural history of PLCH is unpredictable. In some patients, disease may remit or stabilise following smoking cessation. Others develop progressive lung disease, often associated with evidence of airflow limitation and pulmonary vascular dysfunction. Due to the inability to accurately predict the natural history, it is important that all patients undergo longitudinal follow-up at least twice a year for the first few years following diagnosis. The treatment of PLCH is challenging and should be individualised. While there is no general consensus regarding the role of immunosuppression or chemotherapy in management, selected patients may experience improvement in lung function with therapy. Determination of BRAF^V600E or other mutations may assist with the development of an individualised approach to therapy. Patients with progressive disease should be referred to specialised centres and considered for a trial of pharmacotherapy or evaluated for transplantation.

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.

Successful Treatment of Multifocal Histiocytic Sarcoma Occurring after Renal Transplantation with Cladribine, High-Dose Cytarabine, G-CSF, and Mitoxantrone (CLAG-M) Followed by Allogeneic Hematopoietic Stem Cell Transplantation

Histiocytic sarcoma (HS) is a rare, aggressive malignancy. Lesions previously called HS were typically non-Hodgkin lymphomas, not HS. As such, chemotherapy directed at lymphoid neoplasms was frequently successful, but it is unclear if these regimens are ideal for HS. We present a 33-year-old African gentleman who underwent sequential renal transplants for glomerulonephritis. He subsequently developed HS of the upper airway and multiple cutaneous sites. The patient received cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) followed by salvage ifosfamide, carboplatin, and etoposide (ICE) but had continuous progression of cutaneous involvement. Cladribine, high-dose cytarabine, G-CSF, and mitoxantrone (CLAG-M) yielded a partial response with near resolution of disease. Ultimately, the patient achieved a complete remission after myeloablative allogeneic hematopoietic stem cell transplant. HS occurring after solid organ transplant raises the possibility of HS as a potential posttransplant malignancy. The use of CLAG-M has not been reported in HS. In this case, histiocyte-directed chemotherapy with CLAG-M was superior to lymphoma-directed regimens.

Long-term efficacy and safety of cladribine (2-CdA) in adult patients with mastocytosis

Mastocytosis (M) is a clonal myeloid-disabling disorder for which no curative therapy is currently available. Cladribine (2-chlorodeoxyadenosine [2-CdA]) is a synthetic purine analog cytoreductive treatment, for which efficacy is mostly reported in advanced M. Here we report, with a long-term follow-up period (>10 years) efficacy and safety in 68 adult patients with M (36 [53%] had indolent M and 32 [47%] had advanced M) treated by 2-CdA (0.14 mg/kg in infusion or subcutaneously, days 1-5; repeated at 4-12 weeks until 1 to 9 courses). Median 2-CdA courses number was 3.7 (1-9). The overall response rate was 72% (complete remission [R]/major/partial R: 0%/47%/25%) and according to indolent/advanced M was 92% (major/partial R: 56%/36%) and 50% (major/partial R: 37.5%/12.5%), respectively. Clinical improvement was observed for 10 of 11 mediator release and 6 of 7 mast cell infiltration-related symptoms including urticaria pigmentosa and organomegaly (P < .02). Serum tryptase levels decreased (P = .01). Median durations of response were 3.71 (0.1-8) and 2.47 (0.5-8.6) years for indolent and aggressive M, respectively. The most frequent grade 3/4 toxicities were lymphopenia (82%), neutropenia (47%), and opportunistic infections (13%). 2-CdA appears to provide a significant efficacy with some toxicity in various M subtypes, mostly in indolent M, refractory to multiple symptomatic therapies.

Effectiveness of cladribine therapy in patients with pulmonary Langerhans cell histiocytosis

Background

Pulmonary Langerhans cell histiocytosis (PLCH) is a rare disorder characterised by granulomatous proliferation of CD1a-positive histiocytes forming granulomas within lung parenchyma, in strong association with tobacco smoking, and which may result in chronic respiratory failure. Smoking cessation is considered to be critical in management, but has variable effects on outcome. No drug therapy has been validated. Cladribine (chlorodeoxyadenosine, 2-CDA) down-regulates histiocyte proliferation and has been successful in curbing multi-system Langerhans cell histiocytosis and isolated PLCH.

Methods and patients

We retrospectively studied 5 patients (aged 37–55 years, 3 females) with PLCH who received 3 to 4 courses of cladribine therapy as a single agent (0.1 mg/kg per day for 5 consecutive days at monthly intervals). One patient was treated twice because of relapse at 1 year. Progressive pulmonary disease with obstructive ventilatory pattern despite smoking cessation and/or corticosteroid therapy were indications for treatment. Patients were administered oral trimethoprim/sulfamethoxazole and valaciclovir to prevent opportunistic infections. They gave written consent to receive off-label cladribine in the absence of validated treatment.

Results

Functional class dyspnea improved with cladribine therapy in 4 out of 5 cases, and forced expiratory volume in 1 second (FEV1) increased in all cases by a mean of 387 ml (100–920 ml), contrasting with a steady decline prior to treatment. Chest high-resolution computed tomography (HRCT) features improved with cladribine therapy in 4 patients. Hemodynamic improvement was observed in 1 patient with pre-capillary pulmonary hypertension. The results suggested a greater treatment effect in subjects with nodular lung lesions and/or thick-walled cysts on chest HRCT, with diffuse hypermetabolism of lung lesions on positron emission tomography (PET)-scan, and with progressive disease despite smoking cessation. Infectious pneumonia developed in 1 patient, with later grade 4 neutrocytopenia but without infection.

Discussion

Data interpretation was limited by the retrospective, uncontrolled study design and small sample size.

Conclusion

Cladribine as a single agent may be effective therapy in patients with progressive PLCH.

Pulmonary langerhans cell histiocytosis: case series and literature review

Pulmonary Langerhans cell histiocytosis (PLCH) is a rare disease with insidious onset and nonspecific manifestations. The objective of this article was to characterize the clinical manifestations and features of PLCH by retrospectively analyzing clinical data of patients with PLCH in addition to simultaneous review of literature.A retrospective analysis was conducted on clinical data of patients with PLCH (n = 7), whose conditions were diagnosed by biopsy from pulmonary tissue (n = 6) or enlarged lymph nodes in the neck (n = 1) and confirmed by PLCH typical radiological features on computed tomography (CT) scan, between January 2001 and September 2012 at the Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, China. The review of published reports was made to further emphasize the clinical manifestation and radiological features of PLCH.Long history of cigarette smoking was found in 6 patients. Two patients had recurrent pneumothorax and the other 2 had pulmonary arterial hypertension (World Health Organization group 5 pulmonary hypertension), diagnosed through ultrasonic cardiogram. The nodular shadows were revealed by chest CT scan in 5 patients, cystic shadows in 5 patients, and reticular shadows in 2 patients, as major manifestations, respectively; most of the lesions were located in the middle or upper segments of the lung. The obvious shrank of lesion was found in 1 patient after completely quitting smoking.The pathogenesis of PLCH might be closely associated with smoking. The cystic or nodular lesion was the typical radiological features. Further prospective studies with large sample size are required to further validate the study results and understand the clinical characteristics of PLCH to avoid misdiagnosis.

Cladribine (2-chlorodeoxyadenosine) in frontline chemotherapy for adult Langerhans cell histiocytosis: A single-center study of seven cases

BACKGROUND

Adult Langerhans cell histiocytosis is a rare disorder with diverse clinical manifestations and inconsistent treatment outcomes to conventional therapeutic regimens. Cladribine (2-chlorodeoxyadenosine) repeatedly proved effective in cases of relapsed multifocal and multisystem disease forms. In this retrospective study we present an analysis of cladribine in frontline systemic therapy.

MATERIAL AND METHODS

A cohort of seven male patients with biopsy proved multisystem (six cases) and multifocal (one case) Langerhans cell histiocytosis received cladribine at a dose of 5 mg/m(2) subcutaneously (five cases) or by two-hour intravenous infusion (two cases) over five consecutive days, every four weeks for a median of four courses (range 4-6). The treatment was enhanced with cyclophosphamide (300 mg intravenously on days 1-5 in cycles 4-6) and corticoids (dexamethasone 24 mg orally or methylprednisolone 250 mg intravenously on days 1-5 in cycles 4-6) in two patients, with radiotherapy (20 Gy on skin or bone lesions) in three patients and with photochemotherapy (psoralen plus ultraviolet A light, PUVA) on skin lesions in one patient.

RESULTS

All patients achieved clinically relevant treatment response confirmed by positron emission tomography (PET). Durable complete remissions were maintained in six patients (86%), including two patients with hypophysis involvement, with the median follow-up of 37 months (range 15-94; 49.8 ± 35.2 [ 6 ]). One patient had an aggressive, early relapsing disease requiring further treatment lines. The treatment-related toxicities consisted of transient bone marrow suppression affecting the leukocytes predominantly. Grade 3 lymphopenia occurred in five patients (71%) and grade 3 neutropenia in one patient (14%).

CONCLUSION

Cladribine, both as a single agent as well as in combination with an alkylating cytostatic and corticoids, represents an effective treatment option with favorable toxicity profile for adult patients with multisystem or aggressive multifocal form of Langerhans cell histiocytosis.

Pulmonary langerhans cell histiocytosis

Pulmonary Langerhans Cell Histiocytosis (PLCH) is a relatively uncommon lung disease that generally, but not invariably, occurs in cigarette smokers. The pathologic hallmark of PLCH is the accumulation of Langerhans and other inflammatory cells in small airways, resulting in the formation of nodular inflammatory lesions. While the overwhelming majority of patients are smokers, mechanisms by which smoking induces this disease are not known, but likely involve a combination of events resulting in enhanced recruitment and activation of Langerhans cells in small airways. Bronchiolar inflammation may be accompanied by variable lung interstitial and vascular involvement. While cellular inflammation is prominent in early disease, more advanced stages are characterized by cystic lung destruction, cicatricial scarring of airways, and pulmonary vascular remodeling. Pulmonary function is frequently abnormal at presentation. Imaging of the chest with high resolution chest CT scanning may show characteristic nodular and cystic abnormalities. Lung biopsy is necessary for a definitive diagnosis, although may not be required in instances were imaging findings are highly characteristic. There is no general consensus regarding the role of immunosuppressive therapy in smokers with PLCH. All smokers must be counseled on the importance of smoking cessation, which may result in regression of disease and obviate the need for systemic immunosuppressive therapy. The prognosis for most patients is relatively good, particularly if longitudinal lung function testing shows stability. Complications like pneumothoraces and secondary pulmonary hypertension may shorten life expectancy. Patients with progressive disease may require lung transplantation.

Smoking-related interstitial lung diseases

Cigarette smoke, a toxic collection of thousands of chemicals generated from combustion of tobacco, is recognized as the primary causative agent of certain diffuse interstitial and bronchiolar lung diseases. Most patients afflicted with these disorders are cigarette smokers, and smoking cessation has been shown to be capable of inducing disease remission and should occupy a pivotal role in the management of all smokers with these diffuse lung diseases. The role of pharmacotherapy with corticosteroids or other immunomodulating agents is not well established but may be considered in patients with progressive forms of smoking-related interstitial lung diseases.

Smoking-related interstitial lung diseases

Cigarette smoke, a toxic collection of thousands of chemicals generated from combustion of tobacco, is recognized as the primary causative agent of certain diffuse interstitial and bronchiolar lung diseases. Most patients afflicted with these disorders are cigarette smokers, and smoking cessation has been shown to be capable of inducing disease remission and should occupy a pivotal role in the management of all smokers with these diffuse lung diseases. The role of pharmacotherapy with corticosteroids or other immunomodulating agents is not well established but may be considered in patients with progressive forms of smoking-related interstitial lung diseases.

Rare lung diseases III: pulmonary Langerhans' cell histiocytosis

Pulmonary Langerhans' cell histiocytosis (PLCH) is an unusual cystic lung disease that is also characterized by extrapulmonary manifestations. The current review discusses the presenting features and relevant diagnostic testing and treatment options for PLCH in the context of a clinical case. While the focus of the present article is adult PLCH and its pulmonary manifestations, it is important for clinicians to distinguish the adult and pediatric forms of the disease, as well as to be alert for possible extrapulmonary complications. A major theme of the current series of articles on rare lung diseases has been the translation of insights gained from fundamental research to the clinic. Accordingly, the understanding of dendritic cell biology in this disease has led to important advances in the care of 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.

Outcome of pediatric patients with Langerhans cell histiocytosis treated with 2 chlorodeoxyadenosine: a nationwide survey in Japan

The aim of this study was to assess the outcome of treatment with 2-chlorodeoxyadenosine (2-CdA) in pediatric patients with Langerhans cell histiocytosis (LCH) in Japan. We retrospectively identified 17 pediatric LCH patients treated with 2-CdA. All patients were refractory or reactivated cases who had been initially treated according to the JLSG-02 protocol of the Japan LCH study group. At initiation of 2-CdA therapy, 4 patients had primary refractory multisystem (MS) disease with risk organ (RO) involvement (MS+), 9 patients had reactivated MS disease [5 MS+ and 4 without RO involvement (MS-)], and the remaining 4 patients had refractory/reactivated multifocal bone disease (MFB). Treatment with 2-CdA (4-9 mg/m(2)/day) was administered on 2-5 consecutive days and repeated every 3-4 weeks for a period that ranged from 2 to 12 months. Four primary refractory patients were treated with 2-CdA combined with high dose of cytarabine. In MS+ patients, response to treatment was observed in 5 of the 9 patients. In MS-/MFB patients, 5 of the 8 patients showed response to treatment. In the patients who were primary refractory or had reactivation during initial chemotherapy, 4 of 10 patients showed good response. On the other hand, in the patients having reactivation while off therapy, 6 of 7 patients showed good response. These findings suggest that 2-CdA is effective for reactivated LCH while off therapy.

Treatment of recurrent Langerhans cell histiocytosis in children with 2-chlorodeoxyadenosine

The objective of this study was to evaluate the efficacy of 2-chlorodeoxyadenosine (2-CdA), a purine nucleoside analog, in treating recurrent Langerhans cell histiocytosis (LCH) in children. This study retrospectively analysed the clinical records of 13 patients who were seen in the department for recurrent LCH. These patients were treated consecutively with 2-CdA chemotherapy between July 1997 and May 2005. Median age at diagnosis was 4 years 7 months and median pre-treatment duration of disease was 16.4 months. Four children received 0.1 mg kg-1 per day for 7 days and nine patients 5 mg m-2 per day for 5 days, repeated every 21 days. The maximum number of courses of 2-CdA per patient was limited to six. Seventy-six courses of 2-CdA were administered without difficulty. All 13 patients (100%) had a clinical response documented by radiographic investigation. Nine patients did not require additional therapy and remain in complete remission (CR). Four remaining children are currently disease-free after receiving other therapy as irradiation (two cases) or maintenance chemotherapy (vinblastine, prednisone and 6-mercaptopurine) (one case) or chemotherapy (vinblastine) + irradiation (one child) ( Table I). Hematologic toxicity was minimal and no infectious complications were documented. Median follow-up after initiation of 2-CdA treatment was 4 years 3 months (range 7 months - 8 years 2 months). This experience confirms the reported efficacy of 2-CdA in the treatment of LCH. However, further studies are needed to determine the role of this agent in high-risk patient who did not achieve complete remission after 2-CdA administration.

Langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH) is a poorly understood proliferative disease, with different patterns of clinical presentation. Currently it is classified according to the number and type of system involved and the degree of organ dysfunction. The aetiology of the disease remains uncertain, and in some cases the disease is polyclonal, suggesting a reactive condition. Many cytokines have been implicated in the pathogenesis of LCH. Different therapeutic approaches can be considered depending on the affected organ, including surgery, radiotherapy and chemotherapy. Long-term organ dysfunction may remain, despite disease control and/or eradication, making indefinite supportive treatment mandatory. Here we present a literature review on all of the aspects of the disease, treatment approaches and existing protocols, and finally an adult clinical case.

Treatment of refractory Langerhans cell histiocytosis (LCH) with a combination of 2-chlorodeoxyadenosine and cytosine arabinoside

The combination of 2-chlorodeoxyadenosine (2-CDA) and cytosine arabinoside (Ara-C) has been shown to be effective in children with refractory Langerhans cell histiocytosis (LCH). We have treated 5 patients with recurrent LCH with 2-CDA/Ara-C chemotherapy and closely followed immune and hematopoietic function. These patients display a decline in the absolute CD4, CD8, and natural killer cell number, decrease in the CD4/CD8 ratio. Septic events, including pneumocystis infection were present after most of the treatment courses (15/21). These data suggest that 2-CDA /Ara-C, should be considered in resistant and relapsed pediatric patients with LCH with high-risk multiorgan involvement. Consequent profound prolonged combined immune deficiency and myelosupression should be anticipated.

Analysis of outcome for patients with mass lesions of the central nervous system due to Langerhans cell histiocytosis treated with 2-chlorodeoxyadenosine

PURPOSE

To assess the activity and tolerability of 2-chlorodeoxyadenosine (2-CDA) in treating mass lesions of the central nervous system (CNS) due to Langerhans cell histiocytosis (LCH).

PATIENTS AND METHODS

The records of eight children and four adults with CNS LCH who were treated with 2-CDA were reviewed. The pattern of CNS disease included involvement of the hypothalamic-pituitary axis, gadolinium enhancing parenchymal as well as dural and choroid plexus based mass lesions, and atrophy. 2-CDA (5-13 mg/m(2)/day) was given on 3-5 consecutive days and repeated every 2-8 weeks for a period ranging from 3 to 12 months.

RESULTS

Eight patients demonstrated a complete radiographic response to 2-CDA with resolution of all enhancing mass lesions and four patients showed a sustained, partial radiographic response. One patient died from a non-treatment related cause without evidence of LCH on autopsy. With a follow-up ranging from 2 to 10 years after completion of therapy, the 11 surviving patients remain in continuous remission or are progression free. Prolonged bone marrow suppression was the most common toxicity (four patients). Permanent sequelae of CNS LCH, such as panhypopituitarism, diabetes insipidus (DI) and neurocognitive dysfunction, were not found to be reversible with 2-CDA therapy.

CONCLUSIONS

2-CDA is an active agent in patients with CNS LCH, with the possible exception of neurodegenerative disease, and should be further evaluated in a prospective multi-center clinical trial for LCH patients with enhancing mass lesions of the CNS.

Paediatric neuroradiological aspects of Langerhans cell histiocytosis

Langerhans cell histiocytosis, previously known as histiocytosis X, is a complex disease consisting of three entities that are all characterized by a proliferation of the Langerhans cell. The clinical course is variable and ranges from a solitary lytic bone or skin lesion with complete remission to a multisystem disorder with possible lethal outcome. The clinical suspicion can be increased based on radiological findings that are important criteria in defining the extent of the disease involvement. A biopsy is often necessary for establishing the final diagnosis. The lytic craniofacial bone lesions are the most common craniospinal abnormality in Langerhans cell histiocytosis. Abnormalities in the hypothalamic-pituitary region are the most frequent manifestations, often accompanied with diabetes insipidus as the presenting symptom. A range of different central nervous system abnormalities can be recognized. It is important to be able to recognize the extensive spectrum of neuroradiological abnormalities in order to arrive at the diagnosis. Neuroimaging plays an even more important role in assessing the response to treatment or possible relapse.

Systemic and endocrine manifestations of Langerhans' cell histiocytosis: current concepts in diagnosis and management

Langerhans' cell histiocytosis (LCH) is a rare disease of unknown etiology and variable biologic behavior and course. Almost every organ can be affected; however, it frequently involves the bones, lungs, skin and lymph nodes. LCH exhibits a particular predilection for involvement of the hypothalamo-pituitary axis resulting in diabetes insipidus and/or other anterior pituitary deficiencies. Although LCH can sometimes resolve spontaneously, it usually follows a chronic course and systemic treatment is mandatory for the management of multisystem disease. However, a significant number of patients will develop at least one permanent sequela as a consequence of the disease, with diabetes insipidus being the most common. A multidisciplinary approach is always needed in diagnosis, treatment and follow-up of all patients with LCH.

Endocrine manifestations in Langerhans cell histiocytosis

Langerhans cell histiocytosis is a rare, multisystem disease that shows a particular predilection for hypothalamo-pituitary axis involvement. Diabetes insipidus is the most frequent permanent consequence of Langerhans cell histiocytosis, developing in around a quarter of patients. Although the exact prevalence of anterior pituitary hormone deficiencies is not known, it is probably high and is almost always associated with diabetes insipidus. Established pituitary hormone deficiencies are mostly permanent and require prompt diagnosis and treatment, whereas continuous follow-up is needed to detect deficiencies that might evolve later during the course of the disease. Involvement of endocrine tissues other than the pituitary has also been described but is relatively rare. Further studies are needed to evaluate the effect that endocrine deficiencies exert on the overall prognosis of patients with Langerhans cell histiocytosis.

Langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH) is a complex disease entity comprised of three distinct clinical syndromes that demonstrate indistinguishable histology. These syndromes are: eosinophilic granuloma, which is predominantly osseous or pulmonary; Hand-Schûller-Christian's disease, which involves multiple organ systems and, most typically, the skull base; and Letterer-Siwe's disease, the most severe disease manifestation, which typically involves the abdominal viscera. This article reviews our current understanding of Langerhans cell histiocytosis by discussing the history, histology, etiology, and treatment of the disease. It focuses on the radiographic findings and imaging modalities that are the most useful in disease diagnosis and management.

Langerhans cell histiocytosis of vulva in adolescent

Langerhans cell histiocytosis (LCH) affecting child vulva alone is a very rare disease. Only 13 cases of primary vulvar LCH have been previously reported in the medical literature. We describe an additional case in which the LCH was confined to the vulva, with review of the literature. A 16.5-year-old girl presented with papulous and ulcerative lesions on her labia majora and minora. The biopsy revealed a typical histopathologic finding consistent with LCH. A metastatic work-up did not reveal any evidence of the disease except on the vulva. Treatment was carried out according to LCH II protocol. The patient was diagnosed with a recurrent disorder in the vulva 8 months after the completion of primary chemotherapy. For this reason, she underwent second line treatment with 2-chlorodeoxyadenosine. Eighteen months after the second line chemotherapy, the patient has no signs of a local or systemic recurrence. Primary LCH of vulva is very unusual, but we have to keep in mind this possibility when an adolescent girl presents with an atypical chronic lesion on the vulva. This patient appears to be the first case of adolescent 16.5 year old having a solely cutaneous lesion of the vulva

Adult Langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH) is a proliferative histiocytic disorder of unknown cause originating from dendritic cells. The clinical presentation of LCH is highly variable. Although the features of this disease have been well described in children, they remain poorly defined in adults. Here, we review the current knowledge about adult LCH, focussing on clinical presentation, diagnosis, treatment, and prognosis.

Predictors of outcome in children with Langerhans cell histiocytosis

BACKGROUND

Our goal was to examine the clinical course of patients with Langerhans cell histiocytosis (LCH), with a special emphasis on bone disease and to attempt to identify and examine the factors that may predict reactivation and overall prognosis.

PROCEDURE

We conducted a retrospective chart review of 132 consecutive pediatric patients treated at Children's Hospital Los Angeles for LCH from 1984 to 2001.

RESULTS

The risk for reactivation after initial management is significantly higher for patients with multiple bone and those with multiple organ involvement as compared with patients who had a single bone lesion (hazard ratios are 7.1 and 11.6). Patients younger than 1 year in the multiple organ group have an increased risk of death at 2 years when compared with the older patients in that group (hazard ration = 6.2, P = 0.022). Endocrine abnormalities were seen in 20% and 7.5% of patients with or without skull lesions respectively.

CONCLUSIONS

Patients with LCH involving only the bones have a significantly better outcome than those with other organ involvement. Patients with multiple organ involvement who are less than 1 year of age are at high risk of death and should be approached more aggressively upfront.

Multi-centre pilot study of 2-chlorodeoxyadenosine and cytosine arabinoside combined chemotherapy in refractory Langerhans cell histiocytosis with haematological dysfunction

The aim of this study was to assess the efficacy and adverse effects of 2-chlorodeoxyadenosine (2-CdA) and cytosine arabinoside (Ara-C) in children with refractory Langerhans cell histiocytosis (LCH) and haematopoietic dysfunction. Ten patients, with a median age at diagnosis of 0.5 years, were enrolled in this study. Treatment comprised at least two courses of Ara-C (1000 mg/m(2)/d) and 2-CdA (9 mg/m(2)/d) administered for 5d every 4 weeks; subsequent median follow-up was 2.8 years (range 0.03-6.4 years). Among the 7 patients who received at least two courses of therapy, disease activity decreased in 6 patients, and control of disease was achieved in all patients after a median delay of 5.5 months. All patients suffered World Health Organisation (WHO) grade 4 haematological toxicity. Two septic deaths occurred shortly after administration of the first course of 2-CdA/Ara-C; a third patient was withdrawn from the trial after the first course and subsequently died following haematopoietic stem cell transplantation. This series is small, but we conclude that 2-CdA and Ara-C combined chemotherapy probably has major activity in childhood refractory Langerhans cell histiocytosis.

Clinical, genetic, and therapeutic insights into systemic mast cell disease

PURPOSE OF REVIEW

Mast cell disease is markedly heterogeneous in its underlying molecular pathogenesis, clinical presentation, natural history, and specific treatment. Skin-only disease (cutaneous mastocytosis) is infrequent in adults and systemic mastocytosis may be broadly classified as an indolent or aggressive variant based on the absence or presence of impaired organ function. Urticaria pigmentosa and mast cell mediator release symptoms can occur in all categories of mast cell disease and may not be prognostically detrimental. The purpose of this review is to summarize current concepts and recent advances in the pathogenesis and treatment of adult mast cell disease.

RECENT FINDINGS

A series of laboratory investigations has revealed that mast cell disease is a clonal stem cell disorder, and at least two genes (c-kit and PDGFRA) with pathogenetically relevant mutations have been identified. FIP1L1-PDGFRA+ mast cell disease responds completely to imatinib mesylate. Both Asp816Val c-kit+ and molecularly undefined cases have been shown to respond to 2-chlorodeoxyadenosine therapy after failing treatment with interferon-alpha.

SUMMARY

A partial molecular classification of mast cell disease is now possible; Asp816Val c-kit+, FIP1L1-PDGFRA+, and molecularly undefined cases. Such molecular classification is therapeutically relevant.