Histiocytosis syndromes in children

Langerhans cell histiocytosis of the sella in a pediatric patient: case report with review of the literature

PURPOSE

Langerhans cell histiocytosis (LCH) is a rare condition arising from the monoclonal expansion of myeloid precursor cells, which results in granulomatous lesions that characteristically express CD1a/CD207. We report a case of LCH in a 3-year-old male involving the sphenoid bone with extension into the sellar/suprasellar region.

CASE REPORT

A 3-year-old male presented with progressively worsening headaches and associated night sweats, neck stiffness, and fatigue over the previous 4 weeks. Magnetic resonance imaging (MRI) revealed a 2.4-cm lytic lesion within the basisphenoid, exerting mass effect upon the pituitary gland. A biopsy was performed to determine the etiology of the lesion. Postoperatively, the patient developed an intralesional hematoma with visual complications requiring emergent surgical resection via endoscopic endonasal approach. Final pathology confirmed LCH. The patient had improvement in his vision long term.

CONCLUSIONS

LCH extending into the sella is a rare but important diagnosis to consider in pediatric patients presenting with lesions in this region. We presented a case of a pediatric patient presenting with LCH of the sphenoid bone extending into the sella, with subsequent apoplexy and vision loss. Review of the literature showed varying treatment options for these patients, including purely surgical and non-surgical treatments. Early intervention may be necessary to avoid potentially devastating neurologic sequelae.

Additive Prognostic Impact of Gastrointestinal Involvement in Severe Multisystem Langerhans Cell Histiocytosis

OBJECTIVE

To evaluate the prognostic impact of gastrointestinal involvement on the survival of children with Langerhans cell histiocytosis (GI-LCH) registered with the international clinical trials of the Histiocyte Society.

STUDY DESIGN

This was a retrospective analysis of 2414 pediatric patients registered onto the consecutive trials DAL-HX 83, DAL-HX 90, LCH-I, LCH-II, and LCH-III.

RESULTS

Among the 1289 patients with single-system LCH, there was no single case confined to the GI tract; 114 of 1125 (10%) patients with multisystem LCH (MS-LCH) had GI-LCH at initial presentation. GI-LCH was significantly more common in children aged <2 years at diagnosis (13% vs 6% in those aged >2 years; P < .001) and in those with risk organ involvement (15% vs 6% in those without risk organ involvement; P < .001). The 5-year overall survival (OS) in patients without risk organ involvement was excellent irrespective of GI disease (98% vs 97% in patients with GI-LCH; P = .789). In patients with risk organ involvement, the 5-year OS was 51% in 70 patients with GI-LCH vs 72% in 394 patients without GI-LCH (P < .001).

CONCLUSIONS

GI-LCH has an additive unfavorable prognostic impact in children with MS-LCH and risk organ involvement. The emerding need for more intensive or alternative treatments mandates prospective evaluation.

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

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

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

BACKGROUND

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

RESULTS

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

CONCLUSIONS

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

Disseminated juvenile xanthogranuloma occurring after treatment of Langerhans cell histiocytosis: a case report

CASE PRESENTATION

An 11-year-old boy presented with a complaint of a painful temporal mass. Brain magnetic resonance imaging (MRI) showed a 3-cm-sized, homogeneously enhancing mass in the greater wing of the left sphenoid bone, which was diagnosed as Langerhans cell histiocytosis (LCH). Chemotherapy with vincristine and prednisolone was performed for 1 year. After 1 year and 11 months off treatment, he developed symptoms such as polydipsia and polyuria. Brain MRI showed thickening of the pituitary stalk with enhancement, suggestive of LCH involvement, and no recurrence in the sphenoid bone. After 4 years and 4 months off treatment, he developed multiple, subcutaneous, asymptomatic, and yellowish variable-sized papules on his face, posterior neck, and back, which were pathologically diagnosed as juvenile xanthogranuloma (JXG). Brain MRI revealed multifocal enhancing skull lesions in the left parietal, right frontal, and left occipital bones, which were also diagnosed as JXG. After 5 years and 8 months off treatment, the number of variable-sized skin lesions was increased without changes in the lesions in the skull and pituitary stalk.

CONCLUSION

We report a case of disseminated JXG occurring after treatment of LCH. These clinical co-presentations suggested a close relationship between their pathogenesis.

Cutaneous Hematolymphoid and Histiocytic Proliferations in Children

This article focuses on cutaneous hematopoietic neoplasms that are more likely to be encountered in the pediatric age-group and includes both lymphoproliferative and histiocytic disorders. The cutaneous hematologic disorders in children have a different epidemiologic profile to what is seen during adulthood. Although mycosis fungoides is the most frequent form of cutaneous lymphoma in adults, it is very rare in children. Because lymphoblastic leukemias and lymphomas are more frequent in the pediatric setting, cutaneous leukemic infiltrates are relatively common in this age-group. Similarly, histiocytic disorders are more common in children, particularly Langerhans cell histiocytosis and juvenile xanthogranuloma. Notably, the histiocytic disorders have undergone significant modifications on their nomenclature in the basis of the molecular characteristics that are present in them. A summary of the most frequent cutaneous hematopoietic disorders in children will be discussed further in this review.

Prognostic factors for histiocytic and dendritic cell neoplasms

Histiocytic and dendritic cell neoplasms are rare and poorly studied. We report the clinical characteristics and prognostic factors in such cases in Japan. We investigated the clinical characteristics and survival in 87 adult patients with histiocytic and dendritic cell neoplasms. Fifty patients had histiocytic sarcoma, 12 had Langerhans cell histiocytosis, 11 had follicular dendritic cell sarcoma, 8 had Langerhans cell sarcoma, 6 had interdigitating cell sarcoma and 1 had indeterminate dendritic cell sarcoma. The median follow-up period was 18.0 (range: 9.6-71.8) months, and median overall survival (OS) was 23.5 months. The 2-year OS rate was 49.2%. In the multivariate analysis, elevated lactate dehydrogenase (LDH) (p =.004), ECOG performance status (PS) 2-4 (p =.006), and Ann Arbor stage III-IV (p =.008) affected OS. Stratification by elevated LDH, ECOG PS 2-4, and Ann Arbor stage III-IV allowed classification of patients into low risk, intermediate risk, and high risk groups. The same classification was applicable for HS and non-HS categories. In the rare neoplasms of histiocytic and dendritic cell sarcoma, ECOG PS, Ann Arbor stage, and LDH are important prognostic factors for predicting survival.

Genetic homogeneity of adult Langerhans cell histiocytosis lesions: Insights from BRAFV600E mutations in adult populations

Langerhans cell histiocytosis (LCH) is a heterologous disease with a recognized disparity in incidence, affected sites and prognosis between adults and children. The recent identification of BRAF^V600E mutations in LCH prompted the investigation of the frequency of these mutations in adult and childhood disease with the involvement of single or multiple sites in the present study. The study analysed the BRAF^V600E status in a cohort of adult LCH patients by DNA sequencing, and performed a broader meta-analysis of BRAF^V600E mutations in LCH in order to investigate any association with disease site and severity. A review of the literature revealed that ~47% of lesions from cases of adult disease (patient age, >18 years) were V600E-positive compared with 53% in those under 18 years. When single and multiple site disease was compared, there was a slight increase in the former (61 vs. 51%, respectively). A greater difference was observed when high- and low-risk organs were compared; for example, 75% of liver biopsies (a high-risk organ) were reported to bear the mutation compared with 47% of lung biopsies. In the adult LCH population, DNA sequencing identified mutations in 38% of 29 individuals, which is slightly lower than the figure identified from the meta-analysis (in which a total of 132 individuals were sampled), although we this value could not be broken down by clinical status. Thus, V600E status at presentation in itself is not predictive of tumour course, but a considerable proportion of LCH patients may respond to targeted V600E therapies.

Langerhans cell histiocytosis in children diagnosed by fine-needle aspiration

BACKGROUND

Langerhans cell histiocytosis (LCH) is a rare intricate pediatric neoplasm with varied clinical manifestations and multiple treatment modalities.

AIM

To study the cytological features of LCH and the differential diagnoses on fine-needle aspiration (FNA).

MATERIALS AND METHODS

FNA was performed using a 23-gauge needle fitted to a 10 mL syringe mounted on syringe holder. LCH was diagnosed on FNA smears in seven cases confined to the head and neck region, which included three cases of lymphadenopathy, three cases of scalp swelling, and one case of orbital swelling.

RESULTS

The age of the patients ranged from 25 days to 11 years and male-to-female ratio was 1:1.3. Clinically, the diagnoses suggested were tuberculosis, inflammatory lesion, abscess, and malignancy. The cytologic findings included high cellularity, isolated Langerhans cells (LCs) with prominent nuclear indentation, grooves and abundant vacuolated cytoplasm, multinucleated giant cells, eosinophils, and lymphocytes. Areas of necrosis were noted in one case. Histopathology, along with positive S-100 immunohistochemistry, confirmed the diagnosis of LCH.

CONCLUSIONS

LCH is a rare disease occurring predominantly in children and can be diagnosed with ease on FNA cytology by the presence of characteristic Langerhans cells. The S-100 positivity aids in suggesting a diagnosis of LCH.

Potential clinical implications of BRAF mutations in histiocytic proliferations

For a growing number of tumors the BRAF V600E mutation carries therapeutic relevance. In histiocytic proliferations the distribution of BRAF mutations and their relevance has not been clarified. Here we present a retrospective genotyping study and a prospective observational study of a patient treated with a BRAF inhibitor. Genotyping of 69 histiocytic lesions revealed that 23/48 Langerhans cell lesions were BRAF-V600E-mutant whereas all non-Langerhans cell lesions (including dendritic cell sarcoma, juvenile xanthogranuloma, Rosai-Dorfman disease, and granular cell tumor) were wild-type. A metareview of 29 publications showed an overall mutation frequency of 48.5% and with N=653 samples this frequency is well defined. The BRAF mutation status cannot be predicted based on clinical parameters and outcome analysis showed no difference. Genotyping identified a 45 year-old woman with an aggressive and treatment-refractory, ultrastructurally confirmed systemic BRAF-mutant LCH. Prior treatments included glucocorticoid/vinblastine and cladribine-monotherapy. Treatment with vemurafenib over 3 months resulted in a dramatic metabolic response by FDG-PET and stable radiographic disease; the patient experienced progression after 6 months. In conclusion, BRAF mutations in histiocytic proliferations are restricted to lesions of the Langerhans-cell type. While for most LCH-patients efficient therapies are available, patients with BRAF mutations may benefit from the BRAF inhibitor vemurafenib.

Eosinophilic granuloma in the anterior mandible mimicking radicular cyst

Eosinophilic granuloma is a common expression of Langerhans cell histiocytosis and corresponds with typical bone lesions. The radiographic appearance of eosinophilic granuloma in the jaw is variable and not specific. It may resemble periodontitis, radicular cyst, or malignancies. The purpose of this report is to describe the characteristic radiographic features of eosinophilic granuloma of a 39-year-old male. The lesion in the anterior mandible was first diagnosed as radicular cyst because the radiographic findings were ovoid radiolucent lesion with well-defined border. However, careful interpretation revealed a non-corticated border and floating tooth appearance that were the characteristic radiographic features for the differential diagnosis. Early clinical signs of eosinophilic granuloma can occur in the jaw and a bony destructive lesion might be mistaken for periodontitis or an odontogenic cystic lesion; therefore, careful interpretation of radiographs should be emphasized.

Therapy prolongation improves outcome in multisystem Langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH)-III tested risk-adjusted, intensified, longer treatment of multisystem LCH (MS-LCH), for which optimal therapy has been elusive. Stratified by risk organ involvement (high [RO+] or low [RO-] risk groups), > 400 patients were randomized. RO+ patients received 1 to 2 six-week courses of vinblastine+prednisone (Arm A) or vinblastine + prednisone + methotrexate (Arm B). Response triggered milder continuation therapy with the same combinations, plus 6-mercaptopurine, for 12 months total treatment. 6/12-week response rates (mean, 71%) and 5-year survival (84%) and reactivation rates (27%) were similar in both arms. Notably, historical comparisons revealed survival superior to that of identically stratified RO+ patients treated for 6 months in predecessor trials LCH-I (62%) or LCH-II (69%, P < .001), and lower 5-year reactivation rates than in LCH-I (55%) or LCH-II (44%, P < .001). RO- patients received vinblastine+prednisone throughout. Response by 6 weeks triggered randomization to 6 or 12 months total treatment. Significantly lower 5-year reactivation rates characterized the 12-month Arm D (37%) compared with 6-month Arm C (54%, P = .03) or to 6-month schedules in LCH-I (52%) and LCH-II (48%, P < .001). Thus, prolonging treatment decreased RO- patient reactivations in LCH-III, and although methotrexate added no benefit, RO+ patient survival and reactivation rates have substantially improved in the 3 sequential trials. (Trial No. NCT00276757 www.ClinicalTrials.gov).

Sonographic diagnosis and monitoring of localized langerhans cell histiocytosis of the skull

PURPOSE

Langerhans cell histiocytosis (LCH) is an infrequent disorder of unknown origin associated with histiocytic proliferation. The bones' involvement (including cranial bones) is the most frequent manifestation of pediatric LCH. Imaging of skull LCH is based predominantly on conventional radiography, CT, scintigraphy, and sometimes MRI. The aim of the study was to investigate the role of sonography (US) in the diagnosis and monitoring of bone lesions in children with localized LCH of the skull.

METHODS

Twenty-seven children (15 boys/12 girls, mean age 6.1 years) were diagnosed between 1991 and 2005 in the Department of Pediatrics at the Medical University of Gdansk, Poland. Fourteen children (52%) had localized LCH of the skull.

RESULTS

All lesions of the skull visible on CT were visualized on US examination. Overall, 30 focal lesions were revealed by US. The largest bone lesions were accompanied by changes within the adjacent soft tissues. CT revealed 26 lesions, the location and size of which corresponded to the lesions seen on US, but soft-tissue changes adjacent to the bony lesions were difficult to visualize.

CONCLUSIONS

The US appearance of focal LCH lesions in cranial bones in children is not pathognomonic, but is characteristic enough to suggest an initial diagnosis and to monitor the evolution of lesions during treatment. US should be considered an additional diagnostic tool for LCH of the skull. Although US of localized LCH cannot replace CT, it could reduce the number of follow-up CT examinations.

Pathological consequence of misguided dendritic cell differentiation in histiocytic diseases

Histiocytic disorders represent a group of complex pathologies characterized by the accumulation of histiocytes, an old term for tissue-resident macrophages and dendritic cells. Langerhans cell histiocytosis is the most frequent of histiocytosis in humans and has been thought to arise from the abnormal accumulation of epidermal dendritic cells called Langerhans cells. In this chapter, we discuss the origin and differentiation of Langerhans cells and dendritic cells and present accumulated evidence that suggests that Langerhans cell histiocytosis does not result from abnormal Langerhans cell homeostasis but rather is a consequence of misguided differentiation programs of myeloid dendritic cell precursors. We propose reclassification of Langerhans cell histiocytosis, juvenile xanthogranuloma, and Erdheim-Chester disease as inflammatory myeloid neoplasias.

Clinical profile of Langerhans Cell Histiocytosis at a tertiary centre: a prospective study

OBJECTIVE

To study the varied presentations of Langerhans Cell Histiocytosis (LCH), the differential diagnosis of the varied presentations and the time lag in achieving the diagnosis. Prospective analysis of children diagnosed to have LCH over a period of 51 mo was done. A complete history and physical examination was undertaken in all patients, followed by relevant laboratory and radiological evaluation. Biopsy of the appropriate specimen was done. The extent of the disease was documented, accordingly treated and followed up.

RESULTS

There were 16 children with LCH from October 2005 through December 2009. The age ranged from 8 mo to 72 mo. Diagnosis was confirmed by CD1a/S 100 in 15 children (93.75%). The mean time to arrive at the diagnosis was 9.9 mo. Multisystem disease was documented in 11 (68.75%) children and there were 4 (25.0%) cases of pulmonary LCH. The mean time of follow-up was 14.4 mo (range, 1 mo to 50.6 mo). Most common referral diagnoses in LCH patients was recurrent pneumonia and immunodeficiency.

CONCLUSIONS

There is a need for high index of suspicion for diagnosis of LCH; misdiagnosis is frequent. Pulmonary involvement in children with LCH appears common. It is possibly still underdiagnosed. Nail changes are uncommon, but may act as a marker for multisystem disease. In addition to survival data and analysis of prognostic factors, the prospective collection of data on diverse presentations is essential, along with a high index of suspicion for the diagnosis of LCH.

The usefulness of F-18 fluorodeoxyglucose positron emission tomography/computed tomography in patients with Langerhans cell histiocytosis

OBJECTIVE

Langerhans cell histiocytosis (LCH) has a wide spectrum of clinical manifestations, ranging from spontaneous resolution to rapid progression or death, with the risk of permanent consequences. F-18 FDG PET/CT has been used for assessment of LCH patients. However, its clinical implication has not been well elucidated, mainly due to very low incidence of LCH. The aim of this study was to evaluate the clinical usefulness of F-18 FDG PET/CT in LCH patients.

METHODS

A database of 12 patients (mean age 17.8 ± 17.9 years; 7 children, 5 adults) who were diagnosed histopathologically as LCH was retrospectively reviewed. Two patients underwent F-18 FDG PET/CT before and after therapy, 6 patients underwent only before therapy and 4 patients underwent only after therapy.

RESULTS

Nine (75.0%) and 3 patients (25.0%) had single-system (single site and multiple sites) and multisystem involvements, respectively. Pretreatment SUV(max) of patients with multisystem or multiple site involvement of a single-system was significantly higher than that of patients with single site involvement of a single-system (3.29 ± 2.52 vs. 1.63 ± 0.52, p = 0.025). One patient showed multisystem risk organs (lung and bone marrow) involvement. In 2 patients, F-18 FDG PET/CT detected additional active LCH lesions not identified on conventional imaging modalities. In follow-up F-18 FDG PET/CT scans, complete resolution was identified in 2 patients and reactivation in another 2 patients.

CONCLUSIONS

Results of this study suggest that F-18 FDG PET/CT is useful for identification of active lesions, stratification of disease stages, monitoring of therapeutic response, and detection of reactivation in LCH patients.

Pulmonary involvement in pediatric-onset multisystem Langerhans cell histiocytosis: effect on course and outcome

OBJECTIVES

To assess the effect of pulmonary involvement on the course and outcome of multisystem Langerhans cell histiocytosis (MS-LCH) in children.

STUDY DESIGN

We conducted a retrospective analysis of 420 consecutive patients with MS-LCH. In this analysis, the term "risk organs" is defined as involvement of the liver, spleen, and/or hematopoietic system. The effect of pulmonary involvement on survival was assessed with multivariate Cox regression with adjustment for risk organs involvement and age.

RESULTS

Pulmonary involvement in MS-LCH was present at diagnosis in 102 patients (24%). Of the 318 patients without pulmonary involvement at diagnosis, it developed in 28 within a median of 10 months (range, 1 month-5.5 years). The 5-year overall survival rate in patients without risk organ involvement at diagnosis was 96% in patients without pulmonary involvement and 94% in those with pulmonary involvement. In patients with risk organ involvement at diagnosis, the 5-year overall survival rate was 73% in patients without pulmonary involvement and 65% in patients with pulmonary involvement. In multivariate analysis, pulmonary involvement at diagnosis had no significant impact on survival rats (P = .109, hazard ratio = 1.5).

CONCLUSIONS

In multivariate analysis, pulmonary involvement was not an independent prognostic variable and should therefore be excluded from the definition of risk organ involvement in MS-LCH.

Multisystem Langerhans cell histiocytosis in children: current treatment and future directions

Langerhans cell histiocytosis (LCH) is a rare (about 3-5 cases per million children aged 0-14 years), non-malignant disease characterized by proliferation and accumulation of clonal dendritic cells, extreme clinical heterogeneity, and an unpredictable course. Three large-scale, international, prospective therapeutic studies (LCH-I to III) for multisystem LCH (MS-LCH) have been conducted by the Histiocyte Society since 1991. The cumulative lessons from these studies are summarized in this review. Patients with MS-LCH represent a heterogeneous group with respect to disease severity and outcome, therefore treatment stratification and risk-tailored treatment are mandatory. The risk for mortality can be predicted based on involvement of 'risk organs' (e.g. hematopoietic system, liver, and/or spleen) at diagnosis and on response to initial therapy (assessed after 6-12 weeks of treatment). Thus, patients without involvement of risk organs (low-risk group) are not at risk for mortality but need systemic therapy in order to control the disease activity and avoid reactivations and permanent consequences. Patients with risk organ involvement (risk group) are at risk for mortality, and lack of therapy response defines a subgroup with a particularly dismal prognosis (high-risk group). Those patients in the risk group who respond to therapy and survive are at risk for reactivations and permanent consequences. The LCH-I study compared the efficacy of vinblastine and etoposide, and concluded that they are equivalent single-agent treatments for children with MS-LCH. However, the results of this trial were inferior with respect to response rate at week 6, disease reactivation rate, and sequelae, when compared with historical trials using more intensive regimens. The combination of prednisolone and vinblastine was established as a standard first-line treatment through the LCH-II and LCH-III studies. The regimen consists of one to two 6-week courses (continuous oral corticosteroids 40 mg/m2/day for 4 weeks, tapered over 2 weeks plus weekly vinblastine intravenous push) of initial therapy, followed by a continuation phase (three weekly pulses of oral prednisolone 40 mg/m2/day for 5 days plus a vinblastine injection). The addition of a third drug to the standard combination (etoposide in LCH-II and methotrexate in LCH-III) failed to significantly improve survival in the risk group. The remaining mortality in the risk group is about 20%, and up to 40% in the high-risk group. Concerning low-risk MS-LCH, comparison of results of the LCH-II study with historical data suggested that the remaining reactivation rate of about 50% (and possibly permanent consequences) could be reduced by prolongation of the total treatment duration. To study this hypothesis, in the low-risk group of the LCH-III study standard maintenance therapy was randomly given for a total treatment duration of 6 and 12 months. Unpublished preliminary data from this recently closed trial suggested that prolongation of the treatment duration may significantly improve reactivation-free survival. In summary, several studies have shown that systemic therapy is indicated for all patients with MS-LCH. A standard two-drug regimen consisting of an initial 'intensive' phase for 6-12 weeks, followed by a less intensive 'maintenance phase' for a total treatment duration of at least 12 months is recommended for patients treated outside of clinical trials. Non-responders, particularly those with progressive disease in risk organs, are eligible for experimental salvage approaches. Remaining questions will be addressed in the upcoming LCH-IV trial, which is in the process of intensive preparation.

Langerhan's cell histiocytosis: A single institutional experience

Background:

Langerhans cell histiocytosis (LCH) is a disease that primarily affects bone but can be associated with a clinical spectrum that ranges from a solitary bone lesion with a favorable natural history to a multisystem, life-threatening disease process.

Aim:

We analyzed our single institutional experience of managing children with LCH.

Settings and Design:

A total of 40 children of LCH, managed in tertiary cancer center in South India in the period from 2001 to 2005, were evaluated retrospectively.

Materials and Methods:

Clinicopathological features, laboratory findings, treatment modalities and long-term outcome were analyzed.

Results:

Children were aged between 2 months and 12 years, with a mean of 3 years. Majority of the children were below 5 years of age. Group B constituted a bulk of children. Disseminated cases were less (five patients). Liver function dysfunction was seen in four (10%) children. Pulmonary interstitial infiltrates were seen in two (5%) cases. Diabetes insipidus manifested in three patients. There was one death.

Conclusion:

A better understanding of the etiology and pathogenesis of LCH will result in more directed and efficacious treatment regimens.

Langerhans cell histiocytosis in a 5-month-old presenting with biparietal masses

Langerhans cell histiocytosis (LCH) is a rare proliferative disorder that occurs most commonly in the pediatric population as a result of pathological clonal proliferation of Langerhans cells with subsequent damage and destruction to surrounding tissue. Clinically, LCH presents in a variety of ways, which often results in prolonged time to diagnosis and subsequently poorer outcomes. In this case report, the authors describe an unusually early presentation of multisystem LCH in a patient at birth, which resulted in a 5-month delay to diagnosis and treatment. This patient presented both atypically young and with an uncommon initial manifestation of multisystem disease with multiple soft-tissue swellings rather than early skin involvement. Additionally, this patient had an unusual radiographic appearance with biparietal skull destruction on initial skull radiographs and biparietal soft-tissue lesions on CT resembling cephalohematoma at 3 months of age. The clinical and radiological evaluation, pathology, and treatment strategies are discussed, with particular attention paid to the importance of further workup of atypical nonresolving cephalohematomas to prevent disease progression and poorer outcomes.

Cerebrospinal fluid otorrhoea: a rare presentation of Langerhans' cell histiocytosis of the temporal bone

Objective:

To report a case of Langerhans cell histiocytosis of the temporal bone presenting with cerebrospinal fluid fistula.

Patient:

A Caucasian woman presented to a tertiary care centre in Quebec, Canada, with a new onset of cerebrospinal fluid fistula. She had a significant destructive lesion of the temporal bone, and was diagnosed with Langerhans cell histiocytosis on biopsy.

Interventions:

The patient underwent surgical resection with reconstruction of the posterior fossa and tegmen. She suffered a relapse less than one year after surgery, and was finally treated with chemotherapy.

Main outcome and results:

The patient was free of disease at three-year follow up. No recurrence of the cerebrospinal fluid leak was observed after treatment.

Conclusion:

Langerhans cell histiocytosis of the temporal bone with intra-cranial involvement is rare in adults, with only two cases previously reported. Eleven paediatric cases have been reported. To our knowledge, this patient represents the first report of cerebrospinal fluid fistula as the initial presentation of the disease.

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

BACKGROUND

Adult Langerhans cell histiocytosis (LCH) is a rare disease. The combination of vinblastine and prednisone, given in a 6-month course, is the standard of care but prospective randomized trials are lacking.

PATIENTS AND METHODS

We report our monocentric experience in the treatment of seven adult patients with multisystem (MS) LCH (n = 3) or single-system multifocal (SS-m) LCH (n = 4) with the short-course intensive chemotherapy regimen methotrexate, doxorubicin, cyclophosphamide, vincristine, prednisone and bleomicin (MACOP-B).

RESULTS

The overall response rate was 100% [five complete response (CR), two partial response (PR)]. After a median follow-up of 6.5 years, four patients are in first continuous CR and three patients relapsed after 5, 8 and 62 months, respectively. Four patients were evaluated with positron emission tomography (PET) scan: all three PET-negative patients at the end of treatment had a long-lasting response with only one patient relapsing after 5 years. PET scan detected additional bone lesions at diagnosis in two of four patients, changing the treatment program in one of them.

CONCLUSIONS

MACOP-B regimen seems to be very active in the treatment of adult MS or SS-m LCH, with long-lasting responses in five of seven patients. PET scan merits further evaluation in the initial staging and in the evaluation of the response to chemotherapy.

Histiocytes in Familial and Infection-Induced/Idiopathic Hemophagocytic Syndromes May Exhibit Phenotypic Differences

Familial hemophagocytic syndrome (FHS) and infection-associated hemophagocytic syndrome (IAHS) usually present with fever, pancytopenia, hepatosplenomegaly, signs of hepatic dysfunction, bleeding diathesis, and neurological manifestations. FHS is almost uniformly fatal, and IAHS is associated with high mortality. The only distinguishing characteristics are lack of family history and association with infection in the latter. Despite this, sporadic cases of FHS and culture-negative examples of IAHS (idiopathic HS) can be difficult to distinguish and the distinction may have important implications for treatment and family planning. We evaluated the immunophenotype of the macrophages (M phi s) in frozen tissue sections from three cases of hemophagocytic syndrome using a very large panel of monocyte/M phi-associated monoclonal antibodies and an immunoperoxidase technique. The clinical and laboratory features suggested that two were examples of FHS (one with strong family history) and that the third was IAHS/idiopathic HS. The results supported the clinical impressions by showing that the antigenic phenotypes of the FHS cases were nearly identical and different from that of the case of presumed IAHS/idiopathic HS. Specifically, M phi s from the FHS cases expressed complement receptors, 1, 2, and 3 (CD35, CD21, and CD11b, respectively), the monocyte antigen CD36, and the "activation" antigens CD25 (IL2-R) and CD30 (Ki-1), while those from the IAHS/idiopathic case did not. These studies also demonstrated that the M phi s in these cases exhibited some phenotypic differences from those in control tissues, that is, expression of the pan-M phi antigen CD14, the M phi subset antigen identified by antibody G16/1, complement receptors, certain monocyte antigens, and M phi "activation" antigens.(ABSTRACT TRUNCATED AT 250 WORDS)

Imaging Features of Thyroid Involvement by Langerhans Cell Histiocytosis

A 2-year-old male presented with fever, rash, right upper quadrant pain, and hyperbilirubinemia and was diagnosed with Langerhans cell histiocytosis (LCH). Periportal, hepatic, pulmonary, thymic, and thyroid involvement was noted on initial imaging. Thyroid gland involvement by LCH is rare. This case illustrates computed tomography, ultrasonography, and magnetic resonance imaging features of LCH of the thyroid.

Diffuse xanthogranulomatous dermatitis and systemic Langerhans cell histiocytosis: A novel case that demonstrates bridging between non-Langerhans cell histiocytosis and Langerhans cell histiocytosis

The advent of electron microscopy and immunohistochemical stains allowed for reclassification of the histiocytoses based on the predominant cell in the infiltrate. Although the current schema simplicity provides a good foundation, some patients display overlapping clinical and immunohistochemical features that defy classification. The patient herein illustrates bridging between histiocytic disorders. Through this case we review the various conditions classified under the non-Langerhans cell histiocytosis and Langerhans cell histiocytosis rubric.

Langerhans cell histiocytosis

The clinical manifestations of Langerhans cell histiocytosis have been recognized for more than a century. For most of that time, physicians have viewed the disease from different perspectives, interpreting portions of its clinical spectrum as if they were distinct and unrelated entities. More recently, Langerhans cell histiocytosis has been unified into a single concept, though the disease continues to defy traditional classification. By most accounts, Langerhans cell histiocytosis appears to be a morphologically benign proliferation of inflammatory cells that escapes regulatory control mechanisms. Studies from patients with all stages of the disease, however, document clonal proliferation of immune processing cells (i.e., Langerhans cells), suggesting a malignant disease process. The most common ophthalmic manifestation of Langerhans cell histiocytosis is a solitary lesion of orbital bone, which typically responds to minimally invasive therapy. The best management of solitary orbital Langerhans cell histiocytosis is debatable and has been complicated by its recent designation as a risk factor for central nervous system disease. This article summarizes recent developments in understanding the biology of Langerhans cell histiocytosis, reviews its ophthalmic manifestations, prognosis, and the controversy surrounding treatment of isolated orbital disease.

Craniospinal Langerhans cell histiocytosis in children: 30 years' experience at a single institution

OBJECTIVES

The goal of this study was to review a large series of patients with Langerhans cell histiocytosis (LCH) who had craniospinal lesions to assess the long-term course, outcome, and efficacy of treatment of the disease.

METHODS

Forty-four patients with LCH who presented to a single pediatric neurosurgical department between 1976 and 2006 were retrospectively reviewed.

RESULTS

This series included 29 boys and 15 girls, ranging in age from 2 months to 13 years, with a mean follow-up duration of 4.5 years. Twenty-seven patients (61%) had unifocal bone lesions, 12 (27%) had multifocal bone disease, 2 (5%) had solitary hypothalamic-pituitary axis lesions, and 3 (7%) had multiple organ involvement at presentation. Five (19%) of the 27 patients with unifocal bone disease and 4 (33%) of the 12 patients with multifocal bone disease had delayed development of new bone lesions during the follow-up period. The time to development of new bone lesions ranged from 1 month to 1 year. Two of the 3 patients with multiple-organ LCH died. Patient age < or = 2 years at the time of initial presentation was a risk factor for both initial multifocality and eventual dissemination. In all patients with initial multifocal bone involvement or later dissemination of unifocal bone disease, LCH was controlled by chemotherapy, except for 2 who were treated by surgery alone. Three patients had histological evidence of spontaneous resolution of their lesions.

CONCLUSIONS

Patients with unifocal LCH can be effectively treated with surgery alone. Very young patients are more likely to have multifocal disease and disseminations, and will usually require chemotherapy to control their disease. Spontaneously regressing lesions need not be resected; however, a biopsy procedure can be performed for diagnostic purposes.

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.

Progressive nodular histiocytosis - rare variant of cutaneous non-Langerhans cell histiocytosis

Progressive nodular histiocytosis is an extremely rare skin disease is clinically characterized by the coincidence of two distinct lesions, namely, superficial xanthomatous papules up to 5 mm and deep nodules and tumors 1-3 cm. Histologically the nodules represent spindle cell xanthogranulomas. We report a 24-year-old women with these findings. The distinction from other non-Langerhans cell histiocytoses, in particular multiple juvenile xanthogranulomas, which may be more likely to show spontaneous remission, is somewhat unclear; patients with progressive nodular histiocytosis usually follow a serious and disfiguring clinical course.

"Primary" pulmonary Langerhans cell histiocytosis in a two-year-old child: case report and literature review

Langerhans cell histiocytosis (LCH) can involve multiple organs. "Primary" or isolated pulmonary LCH is a well-described entity in young adults but is exceedingly rare in children younger than 15 years of age. The authors report a new case in a 2-year-old girl and review other reported cases in the pediatric population. The patient had had respiratory symptoms since early infancy suggestive of hyperactive airway disease. At 2 years of age, she had severe pulmonary insufficiency with remarkable cystic changes noted on chest imaging studies. Biopsy of a pulmonary lesion confirmed the diagnosis of LCH. She had no other organ involvement. Pulmonary histiocytosis, though rare, should be considered in any child with chronic respiratory disease such as bronchial asthma, especially when the response to anti-asthma treatment is poor and/or there are cystic changes on the chest x-ray.

Biology of Langerhans cells and Langerhans cell histiocytosis

Langerhans cells (LC) are epidermal dendritic cells (DC). They play an important role in the initiation of immune responses through antigen uptake, processing, and presentation to T cells. Langerhans cell histiocytosis (LCH) is a rare disease in which accumulation of cells with LC characteristics (LCH cells) occur. LCH lesions are further characterized by the presence of other cell types, such as T cells, multinucleated giant cells (MGC), macrophages (MPhi), eosinophils, stromal cells, and natural killer cells (NK cells). Much has been learned about the pathophysiology of LCH by studying properties of these different cells and their interaction with each other through cytokines/chemokines. In this review we discuss the properties and interactions of the different cells involved in LCH pathophysiology with the hope of better understanding this enigmatic disorder.

Spontaneous gonadotrophin deficiency recovery in an adult patient with Langerhans cell histiocytosis (LCH)

Langerhans cell histocytosis (LCH) is a rare disease which exhibits a particular predilection for pituitary involvement leading to diabetes insipidus (DI) and other anterior pituitary hormonal deficiencies that are usually permanent and unresponsive to treatment. We report a 35 year old woman with a 10 year history of multisystemic LCH who developed DI, mild hyperprolactinemia, gonadotrophin and partial growth hormone deficiency following a normal delivery that was accompanied with infundibular thickening on pituitary magnetic resonance imaging (MRI). Following several courses of glucocorticoid administration, that were not associated with any substantial improvement, the patient was started on estrogen replacement therapy and cabergoline. After a three year period free of further relapses she developed irregular uterine bleeding. Following estrogen and cabergoline discontinuation she resumed normal menstruation while a repeated MRI of the pituitary showed an almost normal infundibulum. Endocrine investigation revealed normal gonadotrophin axis and prolactin levels, while the patient continues to menstruate, every 30-40 days, ten months after the resumption of her menstrual cycle. This case demonstrates for the first time that LCH induced pituitary deficiencies can run a variable clinical course and even spontaneously recover.

Langerhans’ Cell Histiocytosis: Current Trends and the Role of the Head and Neck Surgeon

Langerhans’ cell histiocytosis (LCH)—once called histiocytosis X— is a complex reticuloendothelial disease that often involves the head and neck. We discuss the current nomenclature of this disease and review its pathologic and clinical characteristics, with particular emphasis on the role of the head and neck surgeon. LCH can be challenging to diagnose, and the otolaryngologist must be familiar with its varied presentations. Because LCH usually responds well to medical therapy and extensive resection can easily cause more morbidity than the disease itself, a minimalist approach to treatment usually provides the best outcome. We also discuss the case of a 9-month-old girl with LCH who presented with aggressive head and neck disease.

Langerhans cell histiocytosis in adults. Report from the International Registry of the Histiocyte Society

Langerhans cell histiocytosis (LCH), characterised by the infiltration of one or more organs by large mononuclear cells, can develop in persons of any age. Although the features of this disease are well described in children, they remain poorly defined in adults. From January 2000 to June 2001, 274 adults from 13 countries, with biopsy-proven adult LCH, were registered with the International Histiocyte Society Registry. Information was collected about clinical presentation, family history, associated conditions, cigarette smoking and treatment, to assist in future management decisions in patients aged 18 years and older. There were slightly more males than females (143:126), and the mean ages at the onset and diagnosis of disease were 33 years (standard deviation (S.D.) 15 years) and 35 years (S.D. 14 years), respectively. 2 patients had consanguineous parents, and 1 had a family history of LCH; 129 reported smoking (47.1%); 17 (6.2%) had been diagnosed with different types of cancer. Single-system LCH, found in 86 patients (31.4%), included isolated pulmonary involvement in 44 cases; 188 patients (68.6%) had multisystem disease; 81 (29.6%) had diabetes insipidus. Initial treatment consisted of vinblastine administered with or without steroids, to 82 patients (29.9%), including 9 who had received it with etoposide, which was the sole agent given to 19 patients. 236 patients were considered evaluable for survival. At a median follow-up of 28 months from diagnosis, 15 patients (6.4%) had died (death rate, 1.5/100 person years, 95% Confidence Interval (95% CI) 0.9-2.4). The probability of survival at 5 years postdiagnosis was 92.3% (95% CI 85.6-95.9) overall, 100% for patients with single-system disease (n=37), 87.8% (95% CI 54.9-97.2) for isolated pulmonary disease (n=34), and 91.7% (95% CI 83.6-95.9) for multisystem disease (n=163). Survival did not differ significantly among patients with multisystem disease, with or without liver or lung involvement) 5-year survival 93.6% (95% CI 84.7-97.4) versus 87.5% (95% CI 65.5-95.9), respectively; P value 0.1). LCH in adults is most often a multisystem disease with the highest mortality seen in patients with isolated pulmonary involvement. It should be included in the differential diagnosis of disseminated or localised disease of the bone, skin and mucosa, as well as the lung and the endocrine and central nervous system, regardless of the age of the patient. A prospective international therapeutic study is warranted.

Expression of cell cycle-related gene products in Langerhans cell histiocytosis

BACKGROUND The pathogenesis of Langerhans cell histiocytosis (LCH), a disease characterized by an abnormal accumulation of the dendritic Langerhans cells, is still unknown. Based on the monoclonality of the CD1a+ cell and reports of familial clustering, it is hypothesized that a genetic alteration at a cellular level may be causative. This genetic change may have an effect on the cellular mechanisms controlling proliferation and apoptosis. MATERIALS AND METHODS LCH-lesions were studied for the expression of Ki-67, present in the nucleus of proliferating cells. Furthermore, the expression of cell cycle-related gene products TGF-beta receptor I and II, MDM2, p53, p21, p16, Rb, and Bcl2 were studied. The TGF-betaR genes play a role in tumor suppression, whereas Bcl2 inhibits apoptosis. The remaining genes are part of either the p53-p21 and/or p16-Rb pathways, which induce cell cycle arrest or apoptosis in response to DNA damage. RESULTS In 30 biopsies the diagnosis of LCH could be confirmed on the basis of CD1a positivity (27 bone and 3 skin). All cases showed scattered nuclear-positive staining for the proliferation marker Ki-67. In more than 90% (n >/=27) of these cases, expression of TGFbeta receptor I and II, MDM2, p53, p21, p16, Rb, and Bcl2 was detected in lesional LCH cells. The overexpression was in general heterogeneous, ranging from limited focal staining of scattered cells within the lesion to strong diffuse staining. CONCLUSIONS These findings suggest that the cellular mechanisms that sense and respond to DNA-damage, namely the p53-p21 pathway and the p16-Rb pathway, are activated. The expression of Ki-67 indicates that the cells in LCH are proliferating. The observed overexpression of Bcl2 may play a role in the activation of p53 and p16 and/or the arrest of apoptosis.