Skeletal involvement in children with Langerhans cell histiocytosis: healing, complications, and functional outcome

Presentation, treatment, and outcomes of unifocal and multifocal osseous vertebral Langerhans cell histiocytosis lesions in patients under 18 years old

This study aims to (1) clinically and radiographically characterize a series of unifocal (single-system single-site) and multifocal (single-system multiple-site) langerhans cell histiocytosis (LCH) lesions in the vertebra and (2) determine the success and recurrence rates with different treatment modalities in a pediatric population at a tertiary children's hospital. Patients younger than 18 years old with a diagnosis of LCH before 1 June 2021 at our institution were reviewed. The inclusion criteria were a unifocal or multifocal vertebral lesion without systemic disease. Clinical presentations, lesion sites, radiographic findings, treatments, complications, recurrence rates, and length of follow-up were reviewed and recorded. Thirty-nine patients had unifocal (36%) or multifocal (64%) vertebral lesions. 44% of patients had vertebral lesions only. The most common clinical presentation was neck or back pain (51%) and difficulty or inability to ambulate (15%). 70 vertebrae were involved in total; 59% cervical, 62% thoracic, 49% lumbar, and 10% sacral. 88% of multifocal patients underwent chemotherapy compared to 60% of unifocal patients. The recurrence rate in the entire cohort was 10%. The median length of follow-up was 5.2 years (0.6-16.8). Chemotherapy is often utilized as a treatment for vertebral LCH lesions regardless of unifocal or multifocal osseous presentation, with good outcomes and low recurrence rates. However other treatments such as observation only and steroid injections may be a better option with smaller and less widespread lesions due to side effects and length of treatment with chemotherapy. Determination of more invasive treatments including surgical excision or fixation will need to be considered on a case-by-case basis. Level of evidence: IV.

Vertebra Plana: A Narrative Clinical and Imaging Overview among Possible Differential Diagnoses

Vertebra plana is a rare radiologic condition characterized by a uniform loss of height of a vertebral body that represents a diagnostic challenge for surgeons. The purpose of this study was to review all possible differential diagnoses that may present with a vertebra plana (VP) described in the current literature. For that purpose, we performed a narrative literature review in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, analyzing 602 articles. Patient demographics, clinical presentation, imaging characteristics and diagnoses were investigated. VP is not a pathognomonic feature of Langerhans cell histiocytosis, but other oncologic and non-oncologic conditions should be considered. The list of differential diagnoses, based on our literature review, can be recalled with the mnemonic HEIGHT OF HOMO: H-Histiocytosis; E-Ewing's sarcoma; I-Infection; G-Giant cell tumor; H-Hematologic neoplasms; T-Tuberculosis; O-Osteogenesis imperfecta; F-Fracture; H-Hemangioma; O-Osteoblastoma; M-Metastasis; O-Osteomyelitis, chronic.

Langerhans Cell Histiocytosis in Children: Literature Review

Relevant information on Langerhans cell histiocytosis development and course in children is presented. The current concepts of disease pathogenesis, principles of its severity evaluation, patients stratification into risk groups, as well as of clinical course features are described. Modern approaches to the disease treatment via targeted therapy are summarized and analyzed. 

Treatment and Outcomes of Unifocal and Multifocal Osseous Pelvic Langerhans Cell Histiocytosis Lesions in a Pediatric Population

Introduction

Langerhans cell histiocytosis (LCH) is a rare, clonal disorder characterized by proliferation and tissue infiltration by myeloid dendritic cells, most commonly occurring in pediatric populations. It often manifests as skeletal lesions with possible pelvic involvement. Few studies have characterized and reviewed outcomes after treatment of isolated pelvic LCH lesions.

Methods

A retrospective single-institution review was conducted on diagnoses of patients younger than 18 with a diagnosis of unifocal or multifocal skeletal LCH lesions involving the pelvis. Clinical presentations, lesion sites, focal classification, radiographic findings, treatments, complications, and recurrence rates were reviewed.

Results

Twenty patients had unifocal or multifocal LCH pelvic lesions (11 males, nine females). The median age at diagnosis was 3.5 years (0.8-21.6). Eight cases (40%) involved unifocal lesions, and twelve (60%) involved multifocal lesions, with the most common associated skeletal disease occurring at the ilium. 100% of cases had a lytic bone lesion with no pathologic fractures. All cases were treated nonoperatively with chemotherapy medications, corticosteroids, or observation alone. 75% of cases were treated with chemotherapy with a 100% resolution rate. The median length of follow-up was 4.5 years (0.4-16.7). 

Conclusion

Our study found that chemotherapy alone or chemotherapy with corticosteroid supplementation are appropriate options for unifocal pelvic LCH lesions. In contrast, pelvic lesions that are part of a multifocal presentation may be managed adequately with varied chemotherapy regimens. Corticosteroid therapy and observation alone may also be reasonable for a single organ system, multifocal, skeletal lesions that are anatomically accessible for biopsy and small in number or size.

Percutaneous CT-guided corticosteroid injection for the treatment of osseous Langerhans cell histocytosis: a three institution retrospective analysis

PURPOSE

The aim of this study is to evaluate the safety and effectiveness of CT-guided corticosteroid injection for the treatment of osseous Langerhans cell histiocytosis (LCH) in a multi-institutional study.

MATERIALS AND METHODS

This IRB-approved study included patients from three institutions. We retrospectively reviewed clinical, procedural, and imaging data for corticosteroid injections performed to treat osseous LCH. Location of the lesion, lesion maximum dimension and volume, corticosteroid type and dose, and time interval between injection and change in lesion size/volume and symptoms were recorded. Generalized estimating equations (accounting for multiple lesions per subject) were used to evaluate the association between predictors (dose, maximum lesion dimension, and lesion volume) and outcomes (time to partial and complete radiographic resolution, and time to pain control). This analysis was adjusted by anatomic site.

RESULTS

Forty corticosteroid injections were performed in 36 patients (20 (56%) females, and 16 (44%) males, ages 12 ± 11 (2-57) years). Mean lesion maximum dimension was 3.2 ± 1.7 cm, and volume was 10 ± 17 cm³. Imaging and clinical follow-up were available for 22/40 (55%) and 34/40 (85%) of injections, respectively. All lesions responded to corticosteroid injection. Times to partial and complete imaging resolution were 13 ± 9 and 32 ± 13 weeks, respectively, and time to pain resolution was 22 ± 14 weeks. There were no complications.

CONCLUSION

CT-guided corticosteroid injection is a safe and effective treatment for LCH. Pain resolution was achieved in all patients and imaging did not show progressive disease in any of the patients.

Long-term complications in uniformly treated paediatric Langerhans histiocytosis patients disclosed by 12 years of follow-up of the JLSG-96/02 studies

Langerhans cell histiocytosis (LCH) is a rare inflammatory myeloid neoplasia derived from immature myeloid dendritic cells with the mitogen-activated protein kinase (MAPK) pathway gene mutation. LCH is rarely fatal, but patients develop various permanent consequences (PCs). We report the frequencies of LCH-related PCs in paediatric patients (n = 317) treated by the JLSG-96/02 AraC-containing regimens. One-third of LCH patients had at least one PC at a median follow-up of 12 years. Central nervous system (CNS)-related PCs (neurological and endocrinological) accounted for 21·5%, non-CNS-related 16·7%. We require novel therapeutic measures to further reduce the frequency of LCH-related PCs.