A multicentre retrospective survey of Langerhans' cell histiocytosis: 348 cases observed between 1983 and 1993. The French Langerhans' Cell Histiocytosis Study Group

High risk Langerhans cell histiocytosis in children: the role of salvage in improving the outcome. A single center experience

BACKGROUND

In pediatric multi-system high risk organs (RO +) Langerhans cell histiocytosis (LCH), failing 1st line treatment has the highest mortality. We aim to present the outcome of failure of 1st line whether due to disease progression (DP) at end of induction or reactivation (REA) after initial better status response.

PATIENTS AND METHODS

Sixty-seven RO + LCH patients with hemopoietic, hepatic or splenic involvement, treated between 2007 and 2019 were retrospectively analyzed. The median follow-up (IQR) is 6 years (4-8.8 y).They were subjected to 2 eras of treatment; one with salvage by 2-Cda based regimen (2-CdABR) and another without.

RESULTS

Of 67 patients, M/F 40/27, median age 1.74 y (0.2-10 y), 42 failed 1st line (62.7%). Of them DP n = 22 (52%) and REA n = 20 (48%). Of those with DP, 9/22 patients received 2-CdABR, where 5 survived in better status. While the remaining 13 did not receive 2-CdABR and all of them died. Otherwise, of those with REA, 12/20 reactivated on RO + mode. Of them, 8/12 received 2-CdABR, where only one survived in better status and the remaining 4 received vinblastine-based regimen,where 2 died and 2 were rescued. RO + 5-year overall survival (OS) was 65% (CI 95% 54 -78) while the event free survival (EFS) 36% (26.3-50.1). The OS of DP 27% (14-54) versus REA 67% (49-93) p 0.004. OS of DP with 2-CdABR 56% (31-97.7) versus 8% without (2-51), p < 0.001. While OS of REA with 2-CdABR 38% (13-100) versus 74% without (53-100) p 0.7.

CONCLUSION

Survival of RO + remains limited. Failure of 1st line in RO + due to DP carries worse prognosis in relation to REA. In DP those who were not salvaged by 2-CdABR, showed dismal outcome. This could not be shown when applied in REA.

Clinicopathologic Features of Gastrointestinal Tract Langerhans Cell Histiocytosis

Gastrointestinal (GI) tract involvement by Langerhans cell histiocytosis (LCH) is rare and its clinicopathologic characteristics have only been described in case reports and small series. We reviewed hematoxylin and eosin- and CD1a, S100, and Langerin immunohistochemical-stained slides from 47 patients with well-documented demographic and clinical findings. Our cases included 8 children and 39 adults, with a mean follow-up of 63 months. All pediatric patients had concurrent multisystem LCH, presented with GI symptoms, and showed non-polypoid lesions. Seven (88%) showed multifocal GI disease, including five with multiple GI organ involvement. All sampled lesions from children exhibited infiltrative growth. More than half had died of the disease or manifested persistent LCH at last follow-up. Twenty-five of 39 (64%) adults had LCH involving only the GI tract (single-system), with the remaining 14 (36%) exhibiting multi-system disease. Adult single-system GI LCH was typically encountered incidentally on screening/surveillance endoscopy (72%). Most exhibited isolated colorectal involvement (88%) as a solitary polyp (92%), with a well-demarcated/noninfiltrative growth pattern (70%), and excellent prognosis (100%). In comparison, adult patients with multi-system LCH more frequently presented with GI symptoms (92%, P<0.001), non-colorectal GI site involvement (50%, P=0.02), multifocal GI lesions (43%, P=0.005), non-polypoid lesions (71%, P<0.001), infiltrative histologic growth pattern (78%, P=0.04), and persistent disease (57%, P<0.001). Adult multi-system LCH patients appear to exhibit similar clinicopathologic features to those of pediatric patients. These results demonstrate that adults with single-system LCH involving the GI tract have an excellent prognosis, while multi-system LCH occurring at any age carries an unfavorable prognosis. High-risk features of GI LCH include pediatric age, GI symptomatology, non-colorectal GI involvement, multifocal GI disease, non-polypoid lesions, and infiltrative growth pattern.

Clinical features and treatment outcomes of liver involvement in paediatric Langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH) is the most common histiocytic disorder in children, and liver involvement in LCH is rare. This retrospective study reported the clinical features and prognosis of patients with hepatic LCH. Liver involvement was defined by histopathological findings, liver dysfunction or abnormalities, or ultrasound imaging. A total of 130 patients (14.5%) with hepatic LCH out of 899 in the LCH population were enrolled. Patients with liver involvement had greater frequencies of skin, lung, hearing system, and haematologic system involvement, and hemophagocytic lymphohistiocytosis (P<0.001, 0.001, 0.002, 0.009, and <0.001, respectively). Overall survival and progression-free survival were lower in LCH patients with liver involvement than in those without liver involvement (P<0.001 and <0.001). In patients with liver involvement, the overall survival (OS) and progression-free survival (PFS) rates were lower in patients with cholangitis than in those without cholangitis (P<0.020 and 0.030). For the treatment response, the response rate of hepatic LCH patients to initial first-line therapy (n=89) was 22.5%. However, there was no significant difference in the response rate or recurrence rate between patients who shifted from first-line treatment to second-line treatment (n=29) or to targeted therapy (n=13) (P=0.453 and 1.000). The response rate of hepatic LCH patients who received initial second-line therapy (n=13) was 38.5%. Two of these patients subsequently experienced bone recurrence. The response rate of hepatic LCH patients who received initial targeted therapy (n=16) was 75.0%. Three patients subsequently experienced recurrence, including 2 in the bone and 1 in the liver and skin. A total of 39.3% of patients who received second-line treatment had severe myelosuppression (grade III-IV), and 50.8% had varying degrees of gastrointestinal events, whereas there was no severe toxicity in patients who received first-line treatment and targeted therapy. Four patients underwent liver transplantation because of liver cirrhosis. The patients' liver disease improved within a follow-up period of 18-79 months. This study demonstrated that LCH with liver involvement, especially cholangitis, indicates a poor prognosis. Targeted therapy provides a good treatment response and less toxicity. However, it may relapse after withdrawal. Liver transplantation is still a reliable salvage option for patients with end-stage liver disease.

Novel therapeutic approaches for pediatric diencephalic tumors: improving functional outcomes

Pediatric diencephalic tumors represent a histopathologically and molecularly diverse group of neoplasms arising in the central part of the brain and involving eloquent structures, including the hypothalamic-pituitary axis (HPA), optic pathway, thalamus, and pineal gland. Presenting symptoms can include significant neurological, endocrine, or visual manifestations which may be exacerbated by injudicious intervention. Upfront multidisciplinary assessment and coordinated management is crucial from the outset to ensure best short- and long-term functional outcomes. In this review we discuss the clinical and pathological features of the neoplastic entities arising in this location, and their management. We emphasize a clear move towards 'function preserving' diagnostic and therapeutic approaches with novel toxicity-sparing strategies, including targeted therapies.

Clinical outcomes and prognostic risk factors of Langerhans cell histiocytosis in children: Results from the BCH-LCH 2014 protocol study

Langerhans cell histiocytosis (LCH) is a rare myeloid neoplasm mainly affecting young children. This study aimed to evaluate the outcomes of 449 pediatric patients enrolled in the BCH-LCH 2014 study. 52.6% of patients were classified with single-system (SS) LCH, 28.1% with multisystem (MS) risk organ negative (RO-) LCH, and 19.4% with MS RO+ LCH. Three hundred ninety-six patients (88.2%) were initially treated with first-line therapy based on the vindesine-prednisone combination. One hundred thirty-nine patients who lacked a response to initial treatment were shifted to second-line therapy, 72 to intensive treatment Arm S1 (a combination of cytarabine, cladribine, vindesine, and dexamethasone), and 67 to Arm S2 (without cladribine). The 5-year overall survival (OS), progression-free survival (PFS), and relapse rates were 98.2% (median: 97.6 months), 54.6% (median: 58.3 months), and 29.9%, respectively. MS RO+ patients had the worst prognosis among the three clinical subtypes. For the patients initially treated with first-line therapy, the 5-year OS, PFS, and relapse rates were 99.2%, 54.5%, and 29.3%, respectively. Patients in Arm S1 had a significantly better prognosis than patients in Arm S2 (5-year PFS: 69.2% vs. 46.5%, p = .042; relapse rate: 23.4% vs. 44.2%, p = .031). Multivariate analysis revealed that early treatment response, the involvement of RO, skin, and oral mucosa, as well as laboratory parameters, including CRP and γ-GT, were independent risk factors for the PFS of LCH. Thus, the prognosis of LCH in children has been improved significantly with stratified chemotherapy, and progression and relapse remained the challenges, especially for RO+ patients.

Outcomes of liver transplantation in children with Langerhans cell histiocytosis: Experience from a quaternary care center

BACKGROUND

Langerhans cell histiocytosis (LCH) is a rare but important cause of end-stage liver disease in children. Conventional chemotherapeutic agents that are otherwise the standard-of-care in LCH may be counterproductive in patients with hepatic decompensation. Furthermore, the precise role of liver transplantation (LT) in the management of LCH remains unclear.

METHODS

Review of a prospectively collected database (January 2014 to December 2020) of children with liver disease was performed. All clinical details of patients with LCH managed at our center were collected and data analyzed. Based on the outcomes, a management algorithm was proposed.

RESULTS

Of the eight (five male) patients referred to our unit, six (75%) underwent LT (four and two for compensated and decompensated cirrhosis, respectively). Median age at diagnosis of LCH was 25 (range: 9-48) months. Two patients, who had previously completed LCH-specific chemotherapy, underwent upfront LT for compensated cirrhosis. Other two patients with compensated cirrhosis showed evidence of active disease. They underwent LT following completion of chemotherapy. Two children with decompensated cirrhosis also had evidence of active disease and were started on modified chemotherapy Both of them had progression of liver disease while on chemotherapy. Hence, an urgent LT was performed which was followed by completion of chemotherapy in these patients. On a median follow-up of 30.5 (10.5-50) months, all post-LT patients were alive with stable graft function and showed no disease recurrence.

CONCLUSION

We demonstrate that an algorithmic approach, along with newer chemotherapeutic agents, results in excellent outcomes in LCH patients with liver involvement. Larger multicentric studies on this rare disease are, however, needed to validate our findings.

Optimal timing of liver transplantation for liver cirrhosis caused by sclerosing cholangitis in a patient with Langerhans cell histiocytosis: a case report

Liver cirrhosis due to secondary sclerosing cholangitis caused by Langerhans cell histiocytosis (LCH) has a poor prognosis, and liver transplantation is the definitive treatment. However, the optimal timing has not been established. We report a 2-year-old girl with LCH-related liver cirrhosis who successfully underwent liver transplantation before progressing to severe liver dysfunction. Physical examination revealed a tumor on her palate. Biopsy was performed, and a diagnosis of LCH was established, together with hepatomegaly, splenomegaly, and rashes. Percutaneous liver biopsy before treatment revealed extreme fibrosis and absence of LCH cells. After beginning chemotherapy, she experienced several delays in treatment and dose reductions because of unacceptable bone marrow suppression, worsening liver dysfunction, and cholangitis. However, tumor shrinkage was observed in both magnetic resonance imaging and BRAF V600E mutant allele titers in her plasma. Given the good treatment response, liver transplantation was conducted. The postoperative course was uneventful, and chemotherapy was resumed 34 days after liver transplantation. Subsequent maintenance treatment was completed with no severe adverse effects. To prevent perioperative complications due to exacerbation of liver dysfunction and possible discontinuation of chemotherapy, liver transplantation should be considered before development of end-stage liver failure, provided that the original disease is well controlled.

Langerhans cell histiocytosis in adults: literature review

Langerhans cells histiocytosis is a variant of malignant histiocytosis. The course and symptoms vary. patients with localized forms have a better prognosis, because local therapy is effective. patients with multifocal forms of histiocytosis receive systemic drug therapy, which cures some of the patients. This review provides up-to-date data about typical presentation of the organ involvement, diagnosis, course and therapy of various forms of Langerhans cells histiocytosis.

Histiocytic disorders

The historic term 'histiocytosis' meaning 'tissue cell' is used as a unifying concept for diseases characterized by pathogenic myeloid cells that share histological features with macrophages or dendritic cells. These cells may arise from the embryonic yolk sac, fetal liver or postnatal bone marrow. Prior classification schemes align disease designation with terminal phenotype: for example, Langerhans cell histiocytosis (LCH) shares CD207+ antigen with physiological epidermal Langerhans cells. LCH, Erdheim-Chester disease (ECD), juvenile xanthogranuloma (JXG) and Rosai-Dorfman disease (RDD) are all characterized by pathological ERK activation driven by activating somatic mutations in MAPK pathway genes. The title of this Primer (Histiocytic disorders) was chosen to differentiate the above diseases from Langerhans cell sarcoma and malignant histiocytosis, which are hyperproliferative lesions typical of cancer. By comparison LCH, ECD, RDD and JXG share some features of malignant cells including activating MAPK pathway mutations, but are not hyperproliferative. 'Inflammatory myeloproliferative neoplasm' may be a more precise nomenclature. By contrast, haemophagocytic lymphohistiocytosis is associated with macrophage activation and extreme inflammation, and represents a syndrome of immune dysregulation. These diseases affect children and adults in varying proportions depending on which of the entities is involved.

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.

Liver Transplantation for Langerhans Cell Histiocytosis: A US Population-Based Analysis and Systematic Review of the Literature

Langerhans cell histiocytosis (LCH) is the most common histiocytic disorder. Liver involvement is seen in 10.1% to 19.8% of patients with LCH and can lead to secondary sclerosing cholangitis requiring liver transplantation (LT). We describe the characteristics and outcomes of patients undergoing LT for LCH. All patients undergoing a first LT for LCH in the United States were identified in the Scientific Registry of Transplant Recipients (SRTR) database (1987-2018). The Kaplan-Meier curve method and log-rank tests evaluated post-LT survival. A systematic literature review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) statement. A total of 60 LCH LT recipients were identified in the SRTR, and 55 patients (91.7%) were children with median total bilirubin levels at LT of 5.8 mg/dL (interquartile range [IQR], 2.7-12.9). A total of 49 patients (81.7%) underwent deceased donor LT (DDLT). The 1-year, 3-year, and 5-year patient survival rates were 86.6%, 82.4%, and 82.4%, respectively. The systematic review yielded 26 articles reporting on 50 patients. Of the patients, 41 were children (82.0%), 90.0% had multisystem LCH, and most patients underwent DDLT (91.9%; n = 34/37). Pre-LT chemotherapy was administered in 74.0% and steroids in 71.7% (n = 33/46) of the patients, and a recurrence of LCH to the liver was reported in 8.0% of the patients. Of the 50 patients, 11 (22.0%) died during a median follow-up of 25.2 months (IQR, 9.0-51.6), and the 1-year patient survival rate was 79.4%. LT can be considered as a feasible life-saving option for the management of liver failure secondary to LCH in well-selected patients.

Findings encountered in percutaneous cholangiography in a case of post-transplant recurrence of hepatic Langerhans cell histiocytosis with biliary involvement

This case report describes a four-year-old boy who presented with the diagnosis of LCH with liver involvement. This required a living-related liver transplant one year later. The primary disease recurred in the transplanted liver 6 months post-transplant and led to progressive biliary dilatation. A percutaneous trans-hepatic cholangiogram was performed five years after transplant, showing a pattern of multifocal biliary duct strictures mimicking the pattern of primary sclerosing cholangitis and a stenosis of the biliary-enteric anastomosis. Despite management with an internal-external biliary drain, the stenosis of the biliary-enteric anastomosis evolved to an occlusion one year after drain removal. This was associated with progression of the changes in the biliary tree, this time associated with significant saccular dilatations secondary to the multiple areas of stenosis. Due to these findings and progressive deterioration of the function of the graft, the patient required re-transplantation. This report illustrates the findings in imaging of the biliary tree secondary to the recurrence of LCH after liver transplantation, which may help to recognize this complication to physicians facing a similar clinical scenario.

Langerhans cell histiocytosis in the occipital condyle: a case study and a brief review of the literature

We present a case study of a 5-year-old patient, who presented with left-sided torticollis. Due to persistence of problems, a CT and an MRI were made showing a single osteolytic lesion centred on right occipital condyle. After an open biopsy, histology confirmed it to be Langerhans cell histiocytosis (LCH). Torticollis or restricted range of motion is a presenting feature in 76% of children with LCH with cervical involvement. There remains much debate on the best treatment strategy. The clinical and radiological outcomes of the case study presented on this article support the treatment of LCH with chemotherapy in cases with solitary involvement of the occipital condyle.

Langerhans Cell Histiocytosis with Uncommon Liver Involvement: A Case Report

Patient: Female, 60-year-old

Final Diagnosis: Langerhans cell histiocytosis

Symptoms: Fatigue • weight loss

Medication: —

Clinical Procedure: —

Specialty: Radiology

Langerhans cell histiocytosis in children under 12 months of age: The spectrum of imaging and clinical findings: Experience in an Irish tertiary referral centre

OBJECTIVES

Langerhans cell histiocytosis is an uncommon condition and it is unusual for it to present in children under one year of age. Our aim is to review the clinical presentation, and present the radiologic findings and clinical outcome in this particular cohort of patients and determine how this differs from the imaging features of older children presenting with LCH.

MATERIALS AND METHODS

A database of 17 patients with LCH who presented between 0 and 12 months of age was retrospectively reviewed. Radiologic findings, initial clinical presentation and ultimate clinical outcome were documented in table format.

RESULTS

Eight patients (47 %) initially presented with cutaneous stigmata, seven patients (41 %) had skeletal involvement, five patients (29 %) had splenic involvement, two patients (24 %) had central nervous system involvement either at presentation or at follow-up, three patients (18 %) had lymphadenopathy, two patients (12 %) had liver involvement, and two patients (12 %) had gastrointestinal (GI) involvement. Four patients (24 %) had multisystem involvement either at presentation or at follow-up. One patient died during follow-up.

CONCLUSION

LCH in children under one year of age is uncommon and may have an unusual clinical presentation. The radiologic findings are varied and may differ from the classical imaging appearance more commonly seen in the older age group, with multisystem involvement seen more readily in younger patients.

Gastrointestinal lesion in adult-onset Langerhans cell histiocytosis

BACKGROUND

Langerhans cell histiocytosis (LCH) is a rare disease primarily occurring in children, and commonly involves the bone and skin; gastrointestinal tract involvement is notably rare. The incidence and significance of gastrointestinal lesions in adult LCH are unclear; thus, we aimed to investigate adult Japanese cases of LCH and clarify the features of gastrointestinal involvement.

METHODS

We gathered clinical information on 43 Japanese cases of adult LCH and analyzed patient backgrounds, affected organs, features of the gastrointestinal lesions, and the clinical courses.

RESULTS

Thirteen patients underwent endoscopic examinations: an upper gastrointestinal endoscopy alone in 5, lower gastrointestinal endoscopy alone in 3, and both in 5 patients. A gastric lesion (one case), colonic lesion (one case), and both gastric and rectal lesions (one case) were detected. The three cases of gastrointestinal involvement also exhibited nongastrointestinal multisystem LCH lesions and showed no gastrointestinal symptoms or increased uptake on positron emission tomography. Endoscopy revealed small erosions without specific features; histological examinations were required for diagnosis. These three cases were treated with chemotherapy, comprising vinblastine/prednisolone, methotrexate, and daily 6-mercaptopurine, for 36 weeks; in two cases, the clinical condition remained stable for several years post-treatment. One case showed recurrence 1 year 7 months after treatment, and chemotherapy was re-administered. No case with single-system disease exhibited gastrointestinal involvement.

CONCLUSIONS

Although gastrointestinal LCH lesions are rare, they were more common than expected in our cases of multisystem LCH. However, these lesions were relatively small and did not affect the patients' clinical courses.

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

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

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

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

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

Multisystem involvement Langerhans cell histiocytosis in an adult: A case report

BACKGROUND

Langerhans cell histiocytosis (LCH) is a rare condition wherein Langerhans cells proliferate abnormally, adversely impacting organs including lymph nodes, bones, skin, lungs, and pituitary gland. The LCH disease course varies widely among patients from a self-limiting condition to one that progresses rapidly and culminates in death. It is uncommon for multisystem LCH to be observed in adults. Herein we describe a woman suffering from multi-system LCH involvement.

CASE SUMMARY

A 37-year old Chinese woman was admitted to the hospital in June 2019 suffering from dyspnea that had progressed over the course of 5 years. Her medical history included: central diabetes insipidus (DI) that had been treated via radiotherapy, desmopressin acetate, and bromocriptine; bilateral pneumothorax with two surgeries having been performed to remove bullae; and autoimmune hepatitis that had been unsuccessfully treated using a combination of methylprednisolone and mycophenolate mofetil. A chest computed tomography (CT) scan revealed the presence of multiple pulmonary cysts of varying sizes. We re-analyzed right pulmonary bullae samples that had been removed in 2014, performed a systematic ¹⁸F-FDG PET/CT analysis, and convened a multidisciplinary medical team to diagnose and treat this patient. As a result, we were able to eventually diagnose this patient with LCH that was not associated with BRAF-V600E mutations.

CONCLUSION

We hope to emphasize the importance of systemic evaluation and of cooperation between multidisciplinary physicians with the goal of improving awareness and detection of this orphan disease.

Adult Langerhans cell histiocytosis presenting with multisystem involvement and sarcomatoid features: a case report

Background

Langerhans cell tumors are rare clonal disorders characterized by neoplastic proliferation of dendritic cells that can be further classified into the subtypes Langerhans cell histiocytosis and Langerhans cell sarcoma, which are rare neoplasms exhibiting aggressive features and a poor prognosis. In addition to illustrating the refractoriness and poor outcomes of multisystem Langerhans cell histiocytosis in adults, specific events in this case highlight important characteristics of disease biology that warrant detailed discussion and exposition to a wider audience.

Case presentation

We describe the case of a 42-year-old Caucasian man with Langerhans cell histiocytosis diagnosed from a lesion on the left arm that presented with constitutional symptoms, early satiety, and weight loss. Esophagogastroduodenoscopy showed extensive esophageal and duodenal involvement by Langerhans cell histiocytosis with features of Langerhans cell sarcoma. He was initially treated for Langerhans cell histiocytosis with low doses of cytarabine until he eventually presented clear transformation to acute monoblastic leukemia with complex karyotype that could not be properly controlled, leading eventually to death.

Conclusions

Langerhans cell histiocytosis remains an exceedingly rare entity in adults, frequently presenting as multisystem disease with risk organ involvement. Langerhans cell sarcoma represents an aggressive subtype with extremely poor prognosis for which intensive acute myeloid leukemia induction should be strongly considered.

Childhood Langerhans cell histiocytosis with severe lung involvement: a nationwide cohort study

BACKGROUND

Lung involvement in childhood Langerhans cell histiocytosis (LCH) is infrequent and rarely life threatening, but occasionally, severe presentations are observed.

METHODS

Among 1482 children (< 15 years) registered in the French LCH registry (1994-2018), 111 (7.4%) had lung involvement. This retrospective study included data for 17 (1.1%) patients that required one or more intensive care unit (ICU) admissions for respiratory failure.

RESULTS

The median age was 1.3 years at the first ICU hospitalization. Of the 17 patients, 14 presented with lung involvement at the LCH diagnosis, and 7 patients (41%) had concomitant involvement of risk-organ (hematologic, spleen, or liver). Thirty-five ICU hospitalizations were analysed. Among these, 22 (63%) were secondary to a pneumothorax, 5 (14%) were associated with important cystic lesions without pneumothorax, and 8 (23%) included a diffuse micronodular lung infiltration in the context of multisystem disease. First-line vinblastine-corticosteroid combination therapy was administered to 16 patients; 12 patients required a second-line therapy (cladribine: n = 7; etoposide-aracytine: n = 3; targeted therapy n = 2). A total of 6 children (35%) died (repeated pneumothorax: n = 3; diffuse micronodular lung infiltration in the context of multisystem disease: n = 2; following lung transplantation: n = 1). For survivors, the median follow-up after ICU was 11.2 years. Among these, 9 patients remain asymptomatic despite abnormal chest imaging.

CONCLUSIONS

Severe lung involvement is unusual in childhood LCH, but it is associated with high mortality. Treatment guidelines should be improved for this group of patients: viral infection prophylaxis and early administration of a new LCH therapy, such as targeted therapy.

Management of severe pulmonary Langerhans cell histiocytosis in children

Patients with pulmonary Langerhans cell histiocytosis (LCH) typically have a benign course but may have extensive cystic lung disease with rare life-threatening complications including multiple and recurrent pneumothoraces and respiratory failure. We report seven severely affected pediatric patients treated with chemotherapy, aggressive chest tube management, and pleurodesis of whom five survived. Patients with extraordinary amounts of pulmonary cystic disease and multiple pneumothoraces due to LCH can have remarkable, curative outcomes with early recognition, optimal LCH-directed therapy, and supportive care.

Multisystemic Pediatric Langerhans cell histiocytosis: a comprehensive clinico-pathological and BRAF V600E mutation study at autopsy

Langerhans cell histiocytosis (LCH), a disorder of antigen-presenting cells, is the commonest disorder of the mononuclear phagocytic system. Diagnosis is always challenging due to heterogeneous clinical presentation. However, with the evolution and better understanding of its biology, many of these children are being diagnosed early and offered appropriate therapy. Despite these advances, in developing countries, an early diagnosis is still challenging due to resource constraints for specialized tests. As a result, many patients succumb to their disease. Autopsy data on LCH is notably lacking in the literature. We sought to analyze the clinical (including mutational) and morphologic features at autopsy in six proven cases of LCH. This study includes a detailed clinico-pathological and mutational analysis of 6 proven cases of LCH. Presence of BRAF V600E mutation was assessed by both Real Time PCR and Sanger sequencing. A varied spectrum of organ involvement was noted with some rare and novel morphological findings, like nodular bronchiolocentric infiltration of LCH cells, lymphovascular emboli of LCH cells, and paucity of eosinophils within the infiltrate; these features have not been described earlier. Surprisingly, all cases were negative for BRAF V600E mutation on both RQ-PCR and Sanger sequencing. The present study is perhaps the first autopsy series on LCH. This extensive autopsy analysis represents a correlation of pathological features with clinical symptoms which provides clues for a timely diagnosis and appropriate therapeutic intervention. Also, our findings hint at the low frequency of BRAF V600E mutation in our LCH patients.

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

OBJECTIVE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Isolated Langerhans cell histiocytosis in the hypothalamic-pituitary region: a case report

BACKGROUND

Langerhans cell histiocytosis (LCH) is a rare disease that mainly affects children, but this disease is significantly rarer in patients who are older than 15 years. In this disease, any organ can be involved. The skeleton, skin and lung are commonly affected, and isolated hypothalamic-pituitary (HP) involvement is relatively rare. Here we report a 17-year-old adolescent with isolated HP-LCH of enlarged pituitary stalk presented with central diabetes insipidus (CDI).

CASE PRESENTATION

A 17-year-old male adolescent with polydipsia and polyuria accompanied with elevated serum sodium level and low urine osmolality for 3 weeks was referred to our hospital. After admission, hormonal evaluation showed that his growth hormone (GH) was slightly elevated, and serum osmolality and glucose were normal. The fluid deprivation-vasopressin test demonstrated CDI. Imaging examination showed an obvious thickening of the pituitary stalk. Lymphocytic hypophysitis, sarcoidosis and granulation tissue lesions were suspected. After oral 1-deamino-8-Darginine vasopressin (DDAVP) and prednisone were administered for 2 months, symptoms were relieved, and he discontinued taking the drugs by himself. On reexamination, imaging revealed changes in the size and shape of the pituitary stalk, with thickened nodules. Then, a diagnostic biopsy of the pituitary stalk lesion was performed. Immunohistochemistry confirmed the definitive diagnosis of LCH. The clinical symptoms subsided with oral hormone replacements.

CONCLUSION

CDI is a rare symptom in children and adolescents. Most of the causes are idiopathic, while others are caused by central nervous system (CNS) disorders. Meanwhile, lymphocytic hypophysitis, germinoma, LCH and other CNS disorders can all present as thickening of the pituitary stalk, diffuse enlargement of the pituitary gland, and weakening of high signal intensity in the neurohypophysis on magnetic resonance imaging (MRI). The differential diagnosis among these diseases depends on immunohistochemistry evidence.

Outcome of High-risk Langerhans Cell Histiocytosis (LCH) in Egyptian Children, Does Intermediate-dose Methotrexate Improve the Outcome?

High-risk multisystem organ (RO+) Langerhans cell histiocytosis (LCH) has the least survival. We present the outcome of RO+ LCH in a pediatric single center. Fifty RO+ LCH patients, treated between 07/2007 and 07/2015, were retrospectively analyzed. Induction vinblastine (VBL) and prednisone (PRED) with intermediate-dose methotrexate (idMTX) was adopted until 2012 (n=20) wherein idMTX was omitted (n=30). The 3-year overall survival (OS) of MTX and non-MTX groups was 75% and 63%, respectively, P=0.537, while the event-free survival (EFS) was 36.9% and 13.2%, respectively, P=0.005. At week 12 of induction, "better status" was obtained in 80% of those receiving MTX, and 55% of those who were not. The statistically significant factors associated with both poor OS and EFS were trihemopoietic cytopenias, hepatic dysfunction, tri RO+ combination, and single induction. The factors associated with disease progression (DP) on induction were trihemopoietic cytopenias, hepatic dysfunction, and lack of idMTX, while those for disease reactivations (REA), the season of autumn/winter, lung disease, male sex, and idMTX were the associated factors. The 1-year OS was remarkably affected with the occurrence of DP versus REA versus none, wherein it was 47%, 93%, and 95%, respectively, P=0.001. In conclusion, idMTX is associated with better EFS. DP on induction remains of dismal prognosis in relation to disease REA afterwards. Risk stratification should highlight the role of trihemopoietic cytopenias, hepatic dysfunction, tri RO+, central nervous system risk site, and lung association.

Langerhans Cell Histiocytosis of the Gastrointestinal Tract: Evidence for Risk Organ Status

OBJECTIVE

To investigate the "risk status" of Langerhans cell histiocytosis (LCH) of the gastrointestinal tract.

STUDY DESIGN

Outcomes from 43 published cases of patients with LCH and gastrointestinal tract involvement were matched to 43 patients with LCH without gastrointestinal tract involvement cared for at our institution. Comparisons were made of the 5-year overall survival rates determined from Kaplan-Meier survival curves for the entire cohort of patients, as well as subgroups defined by lack of risk organ involvement and later era of treatment (to control for temporal changes in LCH treatment regimens). In addition, an association between LCH-gastrointestinal tract and risk organ involvement was investigated.

RESULTS

The 5-year overall survival for children with LCH-gastrointestinal tract (45.3%) was significantly worse than for those without gastrointestinal tract involvement (94.6%; P = .001). This difference remained significant after we excluded risk organ involvement (53.6%% vs 100%; P = .001), and analyzing subjects diagnosed after 2000 (75% vs 100%; P = .012). A 4-fold increase in risk organ involvement with LCH-gastrointestinal tract was observed (OR 4.359; 95% CI 1.75-10.82, P = .001).

CONCLUSIONS

This limited retrospective study suggests that patients with LCH-gastrointestinal tract involvement may have decreased survival, independent of risk organ involvement, and provides evidence to support a prospective study to evaluate risk organ status of LCH-gastrointestinal tract. LCH-gastrointestinal tract may be associated with a 4-fold risk for risk organ involvement. Attention to gastrointestinal symptoms and LCH-gastrointestinal tract in young children diagnosed with LCH is warranted.

Successful treatment with 2-chlorodeoxyadenosine of refractory pediatric Langerhans cell histiocytosis with initial involvement of the gastrointestinal tract

Gastrointestinal (GI) tract involvement in Langerhans cell histiocytosis (LCH) is extremely rare. Langerhans cell histiocytosis with GI tract involvement (GI-LCH) is frequently associated with multi-system disease, and usually presents with severe systemic symptoms, such as protein-losing enteropathy (PLE). Although the GI tract is not included among the organs at risk, the prognosis of GI-LCH is poor, and no effective chemotherapeutic regimen has been identified. Here, we report an infant case of primary refractory GI-LCH with PLE that showed marked improvement in response to 2-chlorodeoxyadenosine (2-CdA) therapy with no severe adverse events, even under conditions of deteriorating general health. The present findings indicate that 2-CdA may be effective for refractory GI-LCH with PLE. Further studies are warranted to determine the optimal therapeutic strategies for GI-LCH with PLE.

Progress towards molecular-based management of childhood Langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH) is characterized by inflammatory lesions containing abundant CD1a+ CD207+ histiocytes that lead to the destruction of affected tissues. This disease has a remarkable pleiotropic clinical presentation and most commonly affects young children. Although the current mortality rate is very low for childhood LCH patients (<2%), reactivation frequently occurs after a long period of disease control and the rates of permanent complications and sequelae remain high. Advances in genomic sequencing technologies in this past decade have highlighted somatic molecular alterations responsible for the disease in around 80% of childhood LCH cases. More than half of these cases harbored the BRAF^V600E mutation, and most other mutations also concerned proteins involved in the MAPKinase pathway. In addition to improving what is known about the LCH pathology, this molecular knowledge provides opportunities to optimize patient management. The BRAF^V600E mutation is associated with more severe presentations of the disease, a high reactivation rate, and a high permanent complication rate; this mutation therefore paves the way for future stratified management approaches. These therapies may be based on the patient's molecular status as well as other clinical characteristics of the disease that are independently associated with undesired events. Moreover, as observed in patients with solid tumors, the BRAF^V600E allele can be detected in the circulating cell-free DNA of patients with severe BRAF^V600E-mutated LCH. Quantification of the plasmatic BRAF^V600E load for this group of patients can precisely monitor response to therapy. Finally, targeted therapies, such as BRAF inhibitors, are new therapeutic options especially designed for refractory multisystemic LCH involving risk organs. However, the long-term efficacy, long-term tolerance, optimal protocol scheme, and appropriate modalities of administration for these innovative therapies for children still need to be defined, a huge challenge.

Langerhans Cell Histiocytosis: Single Center Experience of 25 Years

Objectives

To review a single center outcome of patients with Langerhans Cell Histiocytosis diagnosed at a tertiary referral hospital from Turkey.Methods: The files between 1989 and 2015 of 80 patients with LCH were retrospectively analyzed.

Results

During the 25 years, 80 patients were diagnosed with LCH. The median age at diagnosis was 53 months (2-180 months) and the median follow-up time of patients was 10 years and 9 months (24 months-25 years). Bone was the most frequently affected organ (n:60, 75%). Initially, 43 patients (54%) had single system (SS) disease, 20 patients (25%) had multisystem (MS) disease without risk organ involvement (MS-RO^-), and 17 patients (21%) had a multisystem disease with risk-organ involvement (MS-RO⁺). The overall survival (OS) rate was 91%, and event-free survival (EFS) rate was 67% at 10 years. 10-year OS rate was lower for patients with MS-RO⁺ (65%) when compared to those with, MS-RO^-, and SS (100%, 97%, p value=<0.001). The overall survival rate was also lower in patients with lack of response to systemic chemotherapy on 12th week (p=<0.001), younger age (<2 years) at presentation (p=<0.02), skin involvement (<0.001) and lack of bone lesions at presentation (<0.001).

Discussion

In the group with MS-RO⁺, OS is significantly low compared to other groups. Further efforts are warranted to improve survival in MS-RO⁺ patients.

Langerhans Cell Histiocytosis Presenting as Enterocolitis and Shock in Neonate

INTRODUCTION

Enterocolitis is a relatively common disease in neonatal period that can be a result of many underlying pathologies. One of them, which is an unusual disorder especially in neonatal age and with gastrointestinal involvement, is Langerhans cell histiocytosis (LCH). This case shows a severe neonatal LCH with digestive involvement which required intensive care and had an abnormal presentation, being hard to diagnose attributable to the diversity of symptoms.

CASE REPORT

Eleven-day-old newborn presented for excessive weight loss followed by deterioration to shock, abdominal distension, digestive bleeding, and purpuric exanthema. Exploratory laparotomy identified aggressive enterocolitis. After stabilization, a significant hepatosplenomegaly persists as well as bicytopenia, pyrexia, and cutaneous lesions evolving tangible purple. LCH was diagnosed through histology of cutaneous biopsy.

CONCLUSIONS

Gastrointestinal involvement in neonatal LCH is infrequent and its symptoms can be really unspecific. It is important to know that the first clinical manifestation is usually dermatologic with very diverse morphologies. Having a high suspect rate will lead us to an early diagnosis with its correspondent impact upon the outcome.

Pulmonary Langerhans Cell Histiocytosis: A not so Benign Lesion

Langerhans cell histiocytosis is a multisystem disease affecting young children. Lung involvement has a myriad of manifestations and the outcomes for these patients have been poorly defined. We present a 2-year-old child who presented with multisystem disease with multiple lung cysts. Treatment consisted of multiagent chemotherapy for 18 months and was associated with a slow but favorable response.

Adult Langerhans' cell histiocytosis with multisystem involvement: A case report

RATIONALE

Langerhans' cell histiocytosis (LCH), also called histiocytosis X, is an uncommon disorder manifesting in a variety of ways. Although LCH can involve various organs including bone, skin, and lymph nodes, multisystem involvement of LCH is rare in adults.

PATIENT CONCERNS

A 31-year-old woman first presented to our hospital with left leg pain. She had a history of a 20-kg weight gain over three months.

DIAGNOSES

X-ray, magnetic resonance imaging (MRI), computed tomography (CT), and bone scan images revealed enhancing lesions in the left femur and right temporal bone, multiple cystic lesions in the lung, enhancing mass in the pituitary stalk, and fat density lesions in the liver. The patient underwent excisional biopsy for the femoral lesion and histologic examination confirmed the diagnosis of LCH.

INTERVENTIONS

Excisional biopsy was performed for the bony lesion in the left femur. She received chemotherapy with vinblastine and prednisolone.

OUTCOMES

The patient expired after 21 months from initial admission following recurrent episodes of pneumothorax, pneumonia, and sepsis.

LESSONS

Our case showed LCH involvement in bone, lung, central nervous system (CNS), and liver. Although it is occasionally difficult to discriminate LCH from other disorders, systemic evaluation might be helpful for differential diagnosis. Familiarity with the various multisystemic involvements of LCH on imaging is vital for diagnosing and managing patients in daily practice.

Lower Intestinal Langerhans Cell Histiocytosis Masquerading as Chronic Malabsorption Syndrome and Failure to Thrive in a Child: A Rare Case Presented with a Succinct Review of Recent Literature

Langerhans cell histiocytosis (LCH) encompasses a group of disorders characterized by neoplastic proliferation of Langerhans cells causing destruction of tissue, morbidity and mortality. The authors bring forth the case of a 2-year-old child presenting with chronic diarrhea and features of chronic malabsorption that revealed lesions over the ileocolonic mucosa. Histopathological examination with immunohistochemical expression for CD1a confirmed the diagnosis of LCH. Gastrointestinal LCH is quite uncommon, and review of the published English literature revealed about 50 reported cases. The importance of diagnosing this disease is echoed by the grim survival rate of 18 months from the time of diagnosis that is seen in around 60% of cases. Owing to its rarity and unfamiliarity of practicing physicians and pathologists of this disease at this site, the authors wish to discuss the potential pitfalls and differential diagnoses.

Merkel cell polyomavirus and Langerhans cell neoplasm

BACKGROUND

The relationship between various external agents such as pollen, food, and infectious agents and human sensitivity exists and is variable depending upon individual's health conditions. For example, we believe that the pathogenetic potential of the Merkel cell polyomavirus (MCPyV), the resident virus in skin, is variable and depends from the degree of individual's reactivity. MCPyV as well as Epstein-Barr virus, which are normally connected with humans under the form of subclinical infection, are thought to be involved at various degrees in several neoplastic and inflammatory diseases. In this review, we cover two types of Langerhans cell neoplasms, the Langerhans cell sarcoma (LCS) and Langerhans cell histiocytosis (LCH), represented as either neoplastic or inflammatory diseases caused by MCPyV.

METHODS

We meta-analyzed both our previous analyses, composed of quantitative PCR for MCPyV-DNA, proteomics, immunohistochemistry which construct IL-17 endocrine model and interleukin-1 (IL-1) activation loop model, and other groups' data.

RESULTS

We have shown that there were subgroups associated with the MCPyV as a causal agent in these two different neoplasms. Comparatively, LCS, distinct from the LCH, is a neoplastic lesion (or sarcoma) without presence of inflammatory granuloma frequently observed in the elderly. LCH is a proliferative disease of Langerhans-like abnormal cells which carry mutations of genes involved in the RAS/MAPK signaling pathway. We found that MCPyV may be involved in the development of LCH.

CONCLUSION

We hypothesized that a subgroup of LCS developed according the same mechanism involved in Merkel cell carcinoma pathogenesis. We proposed LCH developed from an inflammatory process that was sustained due to gene mutations. We hypothesized that MCPyV infection triggered an IL-1 activation loop that lies beneath the pathogenesis of LCH and propose a new triple-factor model.

Endocrine and metabolic assessment in adults with Langerhans cell histiocytosis

CONTEXT

Diabetes insipidus (DI) is one of most common complications of Langerhans cell histiocytosis (LCH) but prevalence of anterior pituitary deficiencies and metabolic alterations have not been clearly defined yet.

OBJECTIVES

Evaluate prevalence of endocrine and metabolic manifestations in a cohort of patients affected by Pulmonary LCH.

METHODS

Observational cross-sectional study on 18 adults (7 M/11 F, 42±12years) studied for complete basal and dynamic endocrine lab tests and glucose metabolism.

RESULTS

Hypothalamic-pituitary endocrine alterations were found in 9 patients: 9 had DI, 5 Growth Hormone Deficiency (GHD), 5 central hypogonadism, 3 central hypothyroidism and 1 central hypoadrenalism. Hyperprolactinemia and hypothalamic syndrome were found in 2 patients each. All these central endocrine alterations were always associated to DI. Five of the 10 MRI performed showed abnormalities. Prevalence of obesity and glucose alterations (either DM or IFG/IGT) were respectively 39% and 33%, higher than expected basing on epidemiological data on general Italian population. Multi-system-LCH without risk-organ involvement (LCH MS-RO^-) seems to have slightly higher prevalence of insulin resistance, glucose alterations and metabolic syndrome than LCH with isolated lung involvement (LCH SS lung⁺). A papillary BRAFV600E positive thyroid carcinoma was diagnosed in one patient.

CONCLUSIONS

The presence of anterior pituitary deficiencies should be systematically sought in all LCH patients with DI both at diagnosis and during the follow-up by basal and dynamic hormonal assessment. Patients with pulmonary LCH, particularly those with MS disease, have a worse metabolic profile than general population. Occurrence of papillary thyroid carcinoma has been reported.

Localised Langerhans cell histiocytosis of the hypothalamic-pituitary region: case report and literature review

INTRODUCTION

Langerhans cell histiocytosis (LCH) localised in the hypothalamic-pituitary region (HPR) is very rare, especially in adults. Diabetes insipidus (DI) is considered to be a hallmark of HPR LCH, while anterior pituitary abnormalities are usually seen as consequences of surgery, radiotherapy or chemotherapy.

CASE DESCRIPTION

We present a patient with localised HPR LCH with dominant anterior pituitary dysfunction and tumour mass effects but without DI. Seven years after surgery and local radiotherapy, she is stable. Control MRI shows no residual tumour growth and thorough physical examination is still without any signs of disease spread.

CONCLUSIONS

Anterior pituitary deficiency can appear without DI and not only as a consequence of LCH treatment. All patients with LCH should be screened for this endocrine abnormality so that appropriate substitution therapy may be provided.

Evaluation and treatment of Langerhans cell histiocytosis patients with central nervous system abnormalities: Current views and new vistas

Central nervous system (CNS) involvement in Langerhans cell histiocytosis (LCH) can include mass lesions of the hypothalamic pituitary axis, choroid plexus, cerebrum, and cerebellum or magnetic resonance imaging (MRI) signal abnormalities of the cerebellum, pons, and basal ganglia. The term neurodegenerative (ND) CNS-LCH has been given to the MRI signal abnormalities and neurologic dysfunction, although initially patients may have no clinical symptoms. Standardized evaluations to better understand the natural history and response to therapy are needed. We propose guidelines for clinical, radiologic, and physiologic tests as a framework for developing the best methods of evaluation, which can then be tested in prospective treatment protocols.

Herpes Simplex Virus and Langerhans Cell Histiocytosis

BACKGROUND AND OBJECTIVE

Langerhans cell histiocytosis (LCH) is a rare histiocytic proliferative disorder of unknown etiology and mainly affects young children. The histological feature is granuloma-like proliferation of langerhans-type dendritic cells. Although the possible role of viruses such as Epstein-Barr virus (EBV, Human Herpes virus -4), Human Herpes virus-6 (HHV-6), Herpes Simplex virus (HSV) types 1 and 2 and Cytomegalovirus (CMV, Human Herpes virus-5) is suggested in the pathogenesis of LCH by some investigators, its exact pathophysiology has not been cleared yet. In this study, we investigated the presence of HSV types 1 and 2 in Iranian children with LCH.

METHODS

In this retrospective study, we investigated the prevalence of presence of HSV types 1 and 2 (in 30 patients with LCH), using paraffin-embedded tissue samples and 30 age and tissue-matched controls (operated for reasons other than infectious diseases) from the Department of Pediatric Pathology, Tehran, Iran, by nested Polymerase Chain reaction method. No ethical issues arose in the study, because only the pathology reports were reviewed and patients were anonymous.

RESULTS

We failed to find HSV types 1 and 2 DNA in any of the 30 patients with LCH or the control group.

CONCLUSION

According to our findings, HSV types 1 and 2 do not appear to have any etiologic role in the pathogenesis of LCH in Iranian children. These results are in accordance with previous investigations with negative findings.

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.

Usual and Unusual Manifestations of Familial Hemophagocytic Lymphohistiocytosis and Langerhans Cell Histiocytosis

Familial hemophagocytic lymphohistiocytosis (FHL) and Langerhans cell histiocytosis (LCH) are histiocytic diseases that occur most commonly in young children. Improvements in recognition and treatment have been substantial for both diseases in the past decade, although early and late morbidity continue to be major concerns. These two diagnoses behave differently, although the clinical spectra for both diseases are diverse and can lead to confusion and delays in diagnosis and treatment. This article focuses on the clinical and genetic spectrum of FHL as well as the clinical and treatment variations of LCH.

[Child Langerhans cell histiocytosis]

DEFINITION

Langerhans cell histiocytosis (LCH) is defined by the association of a clinical and radiological involvement and a biopsy of a pathological tissue. Extension: it can affect any organ or system of the body but most commonly the bone (80% of cases), the skin (33%) and the pituitary (25%). Other organs are concerned such as liver, spleen, hematopoietic system and the lungs (15% each), lymph nodes (5-10%) and central nervous system (CNS) excluding the pituitary (2-4%). Natural history: the natural history of the disease is very heterogeneous, ranging from auto-regressive lesions to a disease affecting multiple organs with fatal consequences, while some lesions may be responsible for permanent sequels. A multidisciplinary approach: the perception of disease from physicians varies greatly depending on their speciality and experience, as well as the presentation of the disease or the short-term treatment outcomes. But whatever the initial view of the treating physician, a multidisciplinary approach to the LCH is recommended as well as the coordination of the necessary care of this systemic disease and its associated morbidity.

THERAPY

current treatment protocols, adapted to the situation of each patient, provide a survival of 98% in children. The sequels, such as diabetes insipidus, hormonal deficits, deafness and even more rarely respiratory failure and sclerosing cholangitis are seen in up to 30% of children.

Primary osseous tumors of the pediatric spinal column: review of pathology and surgical decision making

Spinal column tumors are rare in children and young adults, accounting for only 1% of all spine and spinal cord tumors combined. They often present diagnostic and therapeutic challenges. In this article, the authors review the current management of primary osseous tumors of the pediatric spinal column and highlight diagnosis, management, and surgical decision making.

BRAF Mutation Correlates With High-Risk Langerhans Cell Histiocytosis and Increased Resistance to First-Line Therapy

PURPOSE

Langerhans cell histiocytosis (LCH) is an inflammatory myeloid neoplasia with a broad spectrum of clinical manifestations and outcomes in children. The somatic BRAF(V600E) mutation occurs frequently, but clinical significance remains to be determined.

PATIENTS AND METHODS

BRAF(V600E) mutation was investigated in a French LCH cohort. We analyzed associations between mutation status and clinical presentation, extent of disease, reactivation rate, response to therapy, and long-term permanent sequelae.

RESULTS

Among 315 patients with successfully determined BRAF status, 173 (54.6%) carried a BRAF(V600E) mutation. Patients with BRAF(V600E) manifested more severe disease than did those with wild-type BRAF. Patients with BRAF(V600E) comprised 87.8% of patients (43 of 49) with multisystem LCH with risk organ involvement (liver, spleen, hematology), 68.6% of patients (35 of 51) with multisystem LCH without risk organ involvement, 43.9% of patients (86 of 196) with single-system LCH, and 42.1% of patients (8 of 19) with lung-involved LCH (P < .001). BRAF(V600E) mutation was also associated with organ involvement that could lead to permanent, irreversible damage, such as neurologic (75%) and pituitary (72.9%) injuries. Compared with patients with wild-type BRAF, patients with BRAF(V600E) more commonly displayed resistance to combined vinblastine and corticosteroid therapy (21.9% v 3.3%; P = .001), showed a higher reactivation rate (5-year reactivation rate, 42.8% v 28.1%; P = .006), and had more permanent, long-term consequences from disease or treatment (27.9% v 12.6%; P = .001).

CONCLUSION

In children with LCH, BRAF(V600E) mutation was associated with high-risk features, permanent injury, and poor short-term response to chemotherapy. Further population-based studies should be undertaken to confirm our observations and to assess the impact of BRAF inhibitors for this subgroup of patients who may benefit from targeted therapy.