Current concepts for the diagnosis and management of eosinophilic granuloma of bone

Isolated skeletal Langerhans cell histiocytosis in adults: A case report

INTRODUCTION AND IMPORTANCE

LCH in adults is rarely encountered, with the preference in children and axial skeleton as predilection site. Limited understanding of adult LCH causes frequent misdiagnosis, as our experience in an adult case of LCH threw off our differential diagnosis.

CASE PRESENTATION

A 21-year-old male was referred to our hospital due to pain in his right shoulder. Plain radiograph and MRI showed a solitary well-marginated lytic lesion on the distal third of the clavicle. Together with a clear history and physical exam, the benign bone cyst was suspected and we performed an open biopsy simultaneously with curettage followed by internal fixation using a bone graft. Pathology and immunohistochemistry dismissed our suspicion and confirmed LCH as the main diagnosis. At six months post-surgery, no signs of recurrence were seen on the fixated site nor complained by the patient.

DISCUSSION

Diagnosing LCH involves considering imaging appearances and patient demographics as initial clues. However, confirming the diagnosis requires a biopsy with proven CD1 expression. Currently, the majority of studies recommend confirming the diagnosis before initiating therapy. This precaution is necessary due to the unclear pathophysiology of LCH, which complicates the implementation of specific therapies. Based on benign features of skeletal lesions found from imaging, invasive treatment before biopsy confirmation still gave a satisfactory outcome despite not being in line with the current recommendation.

CONCLUSION

Excisional biopsy and curettage in solitary LCH yield satisfactory outcomes. However, further studies are needed with larger sample sizes and interventional designs.

Benign tumors of the chest wall

Benign tumors of the chest wall are rare tumors that might arise from all the tissues of the chest: vessels, nerves, bones, cartilage, and soft tissues. Despite benign features, these tumors can have several histological characteristics and different behaviors. Even if they do not influence life expectancy, rarely they may have a potential risk of malignant transformation. They can cause several, oft, unspecific symptoms but more than 20% of affected patients are asymptomatic and are being diagnosed incidentally on chest radiograph or computed tomography scan. Pain is the most common described symptom. Together with a detailed medical history, a rigorous and meticulous clinical and radiological assessment is mandatory. If radiological features are unclear or in case surgery could not be performed, a biopsy should be indicated to establish a diagnosis. Radical surgical resection can often be offered to resect and cure these neoplasms, but this is might not be true for all types of tumors and, in some cases, their dimension or position might contra-indicate surgery. Given the rarity of these tumors, there is a lack of treatment's guidelines and prospective trials that include a significant number of patients. This review discusses, according to the latest evidence, the histological features and the best treatment of several chest wall benign tumors.

Adult localized Langerhans cell histiocytosis: A case report

BACKGROUND

Langerhans cell histiocytosis (LCH) is a rare clonal proliferative disease of Langerhans cells with unknown pathogenesis. An increasing number of clinicians recognize that LCH has a wide clinical spectrum and a highly varied course. Adults rarely develop LCH. Here, we report a case of adult localized LCH.

CASE SUMMARY

A 32-year-old woman presented with plaques and ulcers on the vulva and crissum, accompanied by pain that persisted for more than one year. Physical examination revealed a red-infiltrating plaque with ulcerations and exudates in the vulva and crissum. Pathological examination revealed a diffuse infiltration of lymphocytes, eosinophilic granulocytes, and histiocytoid cells in the superficial dermis. Proliferative histiocytoid cells showed mild atypia, partly with kidney-shaped nuclei. Immunohistochemical examination showed that the histiocytoid cells were positive for S100 protein and CD1 and weakly positive for CD68 (20% +), with a Ki-67 index of 30%. Laboratory tests did not reveal any other systemic damage. The patient was diagnosed with adult localized LCH and was prescribed oral prednisone (20 mg) once daily. The skin lesions gradually improved and are still being followed-up.

CONCLUSION

Adult localized LCH is rare and must be differentiated from other common conditions.

Benign Bone Tumors Beyond Osteoid Osteoma: Percutaneous Minimally Invasive Image-Guided Interventions

Painful benign bone tumors often adversely influence quality of life primarily due to skeletal-related events such as unremittable pain, pathologic fracture, neurologic deficit, as well as skeletal growth disturbance. Substantial advances in percutaneous minimally invasive interventions for treatment of painful benign bone tumors beyond osteoid osteoma have been established as safe, efficacious, and durable treatments to achieve definitive cure. This article details the available armamentarium and most recent advances in minimally invasive percutaneous interventions and the role of radiologists for the management of patients with benign bone tumors beyond osteoid osteoma.

Application of cementoplasty in patients with symptomatic benign osteopathy disease

BACKGROUND

The optimal treatment for some symptomatic, benign osteopathy lesions is yet to be identified.

PURPOSE

To investigate the clinical efficiency of cementoplasty in managing symptomatic, benign osteopathy.

MATERIAL AND METHODS

Between June 2006 and January 2020, we retrospectively enrolled 31 patients (10 men, 21 women; mean age = 46.5 ± 16.6 years; age range = 20-85 years), accounting for 34 treatment sites, who underwent percutaneous osteoplasty (14 treatment sites) and percutaneous vertebroplasty (20 treatment sites) with digital subtraction angiography (DSA) or DSA combined with computed tomography (CT). All the participants experienced different degrees of clinical symptoms with benign osteopathy lesions. The technical success of the procedure and occurrence of complications were recorded. Follow-up examinations were conducted to assess the treatment outcome using the MacNab criteria.

RESULTS

All the participants had a diagnosis of benign osteopathy lesions before or after the cementoplasty. Surgery was successfully completed in all patients. Cement distributions were diffuse and homogeneous, with the complication of cement leakage occurring in 17.6% (6 of 34) of the lesions. The leakage occurred in the intervertebral disc (n = 1), the intra-articular space (n = 1), and the surrounding soft tissue (n = 4). Analysis of the treatment outcome using the MacNab criteria revealed that all patients showed improvement in their clinical symptoms to some extent and in the quality of life.

CONCLUSION

Cementoplasty is an effective treatment for symptomatic, benign osteopathy, with the advantage of favorable clinical outcomes, and low complication rate.

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 the Pediatric Spine Requiring Stabilization: A Literature Review and Report of 3 Cases

CASE

This report describes 3 cases of Langerhans cell histiocytosis (LCH) of the cervical and thoracic spine in patients aged 4 to 10 years. Each patient had painful lytic spinal lesions with vertebral body collapse and posterior involvement suggesting instability requiring corpectomy, grafting, and fusion. All 3 patients were doing well at their most recent follow-up without pain or recurrence.

CONCLUSION

Although LCH of the pediatric spine is usually successfully treated non-operatively, we recommend corpectomy and fusion when there is instability of the spinal column and/or severe stenosis. Posterior element involvement occurred in all 3 cases and may lead to instability.

Benign Bone Tumors: State of the Art in Minimally Invasive Percutaneous Interventions

Painful benign bone tumors most commonly affect pediatric patients and young adults. They may be associated with skeletal-related events such as intractable pain, pathologic fracture, neurologic deficit as a consequence of nerve or spinal cord compression, as well as growth disturbance. Consequently, they often result in diminished activity and adversely affect quality of life. There have been substantial recent advances in percutaneous minimally invasive image-guided interventions for treatment of painful benign bone tumors including thermal ablation (radiofrequency ablation, cryoablation, microwave ablation, laser photocoagulation, and high-intensity focused US ablation), chemical (alcohol) ablation, cementoplasty, and intralesional injections. The safety, efficacy, and durability of such interventions have been established in the recent literature and as such, the role of musculoskeletal interventional radiologists in the care of patients with benign bone lesions has substantially expanded. The treatment goal of minimally invasive musculoskeletal interventions in patients with benign bone tumors is to achieve definitive cure. The authors detail the most recent advances and available armamentarium in minimally invasive image-guided percutaneous interventions with curative intent for the management of benign bone tumors. ^© RSNA, 2022.

Multifocal eosinophilic granuloma with femoral epiphyseal lesion mimicking an aneurysmal bone cyst

Eosinophilic granuloma (EG) is a rare benign tumor-like disorder characterized by abnormal proliferation Langerhans cells. EG frequently presents as a solitary lesion in the axial skeleton and diaphysis long bones. Here we present the case of a 14-year-old male with multifocal EG with a lesion located in the femoral epiphysis mimicking an aneurysmal bone cyst that presented a diagnostic challenge. While the initial presentation of EG patients may appear uncommon, its overlapping features with other benign and malignant etiologies highlight the importance of increased awareness of this condition, as well as the need for an experienced multidisciplinary team in its diagnosis and treatment.

Langerhans cell histiocytosis. Advances in pathogenesis and clinical practice

Langerhans cell histiocytosis (LCH) is a type of myeloid neoplasia that can affect different organs or tissues and exhibits substantial variability in its clinical presentation and biological behaviour, so it may mimic different diseases. Performance of different clinical assessments and laboratory and imaging tests is recommended to determine the extent of involvement, which may be of a single location or multisystemic, and the presence or absence of dysfunction in risk organs, such as the haematopoietic system, liver and spleen. The diagnosis must be confirmed by histological examination of a biopsy sample. Molecular tests have identified mutations in the mitogen-activated protein kinase (MAPK) pathway, which has expanded treatment options. The diagnosis is complex and there is controversy regarding the management of certain cases. Treatment recommendations depend on the location of the lesions and the extent of involvement. International collaborative studies have demonstrated the effectiveness of prolonged combination therapies such as vinblastine and prednisone in severe or multisystemic forms, and anti-inflammatory drugs such as indomethacin and other cytostatic combinations have proven beneficial. Langerhans cell histiocytosis is a good example of the importance of precision medicine and the benefit of identifying molecular targets, common to different neoplasms, to develop new therapies. MAPK pathway inhibitors offer an alternative treatment option in refractory cases and neurodegenerative forms of LCH. Molecular testing can contribute to the prognosis, treatment and follow-up of LCH, especially in severe forms of disease.

Spectrum of anatomical variants, normal findings and pathology in and around the paediatric sternum

Abnormalities of the sternum and adjacent structures are an uncommon presentation in the paediatric population and can have a variety of benign and malignant causes, including normal and developmental variants of the chest wall. Although there is overlap with adults, many sternal abnormalities are unique to the paediatric population. Following clinical examination, radiography is usually the first type of imaging used; however, it is limited and often ultrasound and cross-sectional imaging are needed for further assessment. An understanding of the normal anatomy is important; however, this can be challenging due to the varied appearances of age-related changes of the sternum. The purpose of this article is to familiarize the general paediatric radiologist with the expected anatomy and imaging findings of the developing sternum, anatomical variants and pathology of the sternum and adjacent structures encountered in this group of patients.

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.

Enchondroma in the Diaphysis of Tibia - A Case Report and Review of its Characteristics and Differentials in the Diaphysis

Introduction

Enchondroma is a solitary, benign, intramedullary cartilaginous tumor commonly noticed in the phalanges of hands and feet with characteristic radiological features. Its occurrence in aberrant sites with atypical features lead to diagnostic dilemma. Enchondromas which are usually managed non-operatively can mimic other benign and malignant lesions, especially chondrosarcoma.

Case Report

We report the case of a 31-year-old farmer who presented with long standing inconspicuous pain in his left leg which turned out to be a diaphyseal enchondroma even though it demonstrated aggressive radiological features mimicking a chondrosarcoma. Incisional biopsy was done from the scalloped areas to obtain the correct histological diagnosis. He underwent thorough curettage of the lesion and remains asymptomatic 2 years after the procedure. We attempt to discuss the differentials which the orthopedic surgeon should keep in mind for diaphyseal lesions mimicking enchondroma.

Conclusion

Though classically found in metaphysis, Enchondromas are not uncommon in diaphysis of long bones. Enchondromas are generally benign, but can cause diagnostic dilemma when they present with aggressive features at rare locations and surgeons should be wary of the differentials. Despite a size of more than 6 cm and evidence of cortical erosion and intramedullary widening, the lesion could still be benign. Early biopsy will help to differentiate Enchondroma from a malignant transformation or malignant tumor.

A deep learning-machine learning fusion approach for the classification of benign, malignant, and intermediate bone tumors

OBJECTIVES

To build and validate deep learning and machine learning fusion models to classify benign, malignant, and intermediate bone tumors based on patient clinical characteristics and conventional radiographs of the lesion.

METHODS

In this retrospective study, data were collected with pathologically confirmed diagnoses of bone tumors between 2012 and 2019. Deep learning and machine learning fusion models were built to classify tumors as benign, malignant, or intermediate using conventional radiographs of the lesion and potentially relevant clinical data. Five radiologists compared diagnostic performance with and without the model. Diagnostic performance was evaluated using the area under the curve (AUC).

RESULTS

A total of 643 patients' (median age, 21 years; interquartile range, 12-38 years; 244 women) 982 radiographs were included. In the test set, the binary category classification task, the radiological model of classification for benign/not benign, malignant/nonmalignant, and intermediate/not intermediate had AUCs of 0.846, 0.827, and 0.820, respectively; the fusion models had an AUC of 0.898, 0.894, and 0.865, respectively. In the three-category classification task, the radiological model achieved a macro average AUC of 0.813, and the fusion model had a macro average AUC of 0.872. In the observation test, the mean macro average AUC of all radiologists was 0.819. With the three-category classification fusion model support, the macro AUC improved by 0.026.

CONCLUSION

We built, validated, and tested deep learning and machine learning models that classified bone tumors at a level comparable with that of senior radiologists. Model assistance may somewhat help radiologists' differential diagnoses of bone tumors.

KEY POINTS

• The deep learning model can be used to classify benign, malignant, and intermediate bone tumors. • The machine learning model fusing information from radiographs and clinical characteristics can improve the classification capacity for bone tumors. • The diagnostic performance of the fusion model is comparable with that of senior radiologists and is potentially useful as a complement to radiologists in a bone tumor differential diagnosis.

A case of childhood tuberculosis from late mediaeval Somerset, England

BACKGROUND

The remains of a 3-5 year-old child from the late mediaeval cemetery serving the Priory of St. Peter and St. Paul, Taunton, Somerset, UK was the subject of an aDNA study.

OBJECTIVE

The aim was to distinguish between two differential diagnoses suggested by earlier osteological examination of the remains; either tuberculosis or Langerhans cell histiocytosis.

FINDINGS

The remains tested positive for MTB complex markers, corroborating this diagnosis reached on osteological grounds. Based on positivity for the mtp40 element and a deletion in the pks15/1 locus, we conclude that infection was due to a strain of the human pathogen M.tuberculosis belonging to lineage 4. Although DNA recovered from the case was heavily fragmented, sex determination by amelogenin PCR suggested these are the remains of a young male child. The findings are discussed considering additions to the literature since the original report.

CONCLUSIONS

Descriptions of tuberculosis in children from this period are rare and burial Sk2077 represents the first UK example of a pre-adolescent individual to have a molecular diagnosis combined with osteological pathology. This provides an important reference of childhood tuberculosis and insight into the likely presence of tuberculosis in the mediaeval adult population served by this cemetery.

Solitary tibial lesion as the initial presentation of Langerhans cell histiocytosis: report of two cases and literature review

The various presentations of osseous Langerhans cell histiocytosis (LCH) make it difficult to distinguish from other bone diseases. In addition, there is no universally accepted protocol for managing osseous LCH for single non-central nervous system-risk lesions. Here, the rare cases of two paediatric patients, aged 1 and 2 years, who presented with a solitary tibial lesion at time of LCH diagnosis, are reported. One patient progressed to multiple lesions after curettage of the original lesion. Subsequently, both patients received preventive chemotherapy using the Taiwan Paediatric Oncology Group (TPOG) revised protocol for treating low risk patients with LCH, namely, TPOG LCH2002-LR. After receiving this treatment, which included a schedule of prednisolone and vincristine for 6 weeks, followed by prednisolone, vincristine and 6-mercaptopurine for a further 48 weeks, both patients are free from recurrence or progression.

Using Machine Learning to Unravel the Value of Radiographic Features for the Classification of Bone Tumors

Objectives

To build and validate random forest (RF) models for the classification of bone tumors based on the conventional radiographic features of the lesion and patients' clinical characteristics, and identify the most essential features for the classification of bone tumors.

Materials and Methods

In this retrospective study, 796 patients (benign bone tumors: 412 cases, malignant bone tumors: 215 cases, intermediate bone tumors: 169 cases) with pathologically confirmed bone tumors from Nanfang Hospital of Southern Medical University, Foshan Hospital of TCM, and University of Hong Kong-Shenzhen Hospital were enrolled. RF models were built to classify tumors as benign, malignant, or intermediate based on conventional radiographic features and potentially relevant clinical characteristics extracted by three musculoskeletal radiologists with ten years of experience. SHapley Additive exPlanations (SHAP) was used to identify the most essential features for the classification of bone tumors. The diagnostic performance of the RF models was quantified using receiver operating characteristic (ROC) curves.

Results

The features extracted by the three radiologists had a satisfactory agreement and the minimum intraclass correlation coefficient (ICC) was 0.761 (CI: 0.686-0.824, P < .001). The binary and tertiary models were built to classify tumors as benign, malignant, or intermediate based on the imaging and clinical features from 627 and 796 patients. The AUC of the binary (19 variables) and tertiary (22 variables) models were 0.97 and 0.94, respectively. The accuracy of binary and tertiary models were 94.71% and 82.77%, respectively. In descending order, the most important features influencing classification in the binary model were margin, cortex involvement, and the pattern of bone destruction, and the most important features in the tertiary model were margin, high-density components, and cortex involvement.

Conclusions

This study developed interpretable models to classify bone tumors with great performance. These should allow radiographers to identify imaging features that are important for the classification of bone tumors in the clinical setting.

ODONTOLOGICAL EFFECTS OF IONIZING RADIATION (review)

BACKGROUND

Odontological effects of ionizing radiation (IR) as a result of radiotherapy, the consequences of accidents at nuclear power plants and industry, individual occupational exposure, etc. deserve significant attention interns of radiation medicine and radiation safety.

OBJECTIVE

to analyze and summarize clinical and experimental data on the odontological radiation effects.

MATERIALS AND METHODS

OBJECT

the pathological changes in the hard tissues of teeth, pulp, periodontium, mucousmembranes of the mouth and jaws due to exposure to IR.

METHOD

search in the PubMed / MEDLINE, Google Scholarabstract medical and biological databases, scientific libraries of the relevant sources of scientific information.

RESULTS

Radiobiological effects of IR due to its direct and indirect action are manifested throughout the period ofodontogenesis and formation of the facial skeleton. Experimental and clinical data (in children and adults) indicatethe increased risk of dental caries, reduction of pain threshold and vascularization of tooth pulp along with its fibrosis and atrophy, periodontal dysfunction, which predispose to a high probability of tooth loss. Abnormalities in theactivity of osteoblasts and cementoblasts of dental periosteum and osteoblasts of alveolar process in combinationwith circulatory disorders due to endothelial cell death, hyalinization, thrombosis and vascular obliteration increasethe risk of jaw osteoradionecrosis. Children who have undergone a prenatal exposure to IR as a result of theChornobyl NPP accident have a premature change of teeth. Deterioration of periodontal tissues and early development of acute and complicated dental caries are typical for children and adults affected by the Chornobyl disaster.

CONCLUSIONS

Summarized data on the effects of radiation exposure under different conditions on teeth primordia(i.e. immature teeth), their formation and eruption in experimental and clinical settings, as well as on the odontological radiation effects in adults are summarized. Condition of the teeth in the Chornobyl NPP accident survivorsis described. Understanding and taking into account the radiobiological odontological effects is necessary in thelight of planning, preparing, and conducting local radiation therapy and developing the standards of radiation safety and measures to protect professionals and the public in the event of possible radiation accidents at the nuclearpower plants and industry facilities.

Plasmacytoma Masquerading as Meningioma

Solitary bone plasmacytoma is a rare disease in the skull. We present a 70-year-old patient who presented with a skull deformity due to the left parietooccipital tumor. Neurological examination found no deficit. The systemic scanning revealed no additional lesion. The surgery was planned, and the tumor was removed totally with the marginal bone around it. Histopathological examination confirmed solitary bone plasmacytoma. The patient is being followed-up without recurrence or progression to multiple myeloma. As the calvarial solitary bone plasmacytomas can be easily misdiagnosed preoperatively, the detailed examination of the CT features may be helpful for the planning and course of the surgery.

Unifocal Langerhans cell histiocytosis of bone: percutaneous navigational bipolar radiofrequency ablation for curative treatment

In this report, the initial clinical experience of authors is described on the novel application of a navigational bipolar radiofrequency ablation electrode system for curative treatment of a painful unifocal Langerhans cell histiocytosis involving the supra-acetabular iliac bone. The technical success and safety of the radiofrequency ablation procedure to achieve cure suggests that this intervention may be utilized in clinical practice as a viable and minimally invasive alternative option, for management of unifocal Langerhans cell histiocytosis.

Vertebra Plana in Children May Result from Etiologies Other Than Eosinophilic Granuloma

BACKGROUND

Vertebra plana in children is a diagnostic dilemma for orthopaedic surgeons. This radiographic finding sometimes has been said to be pathognomonic for eosinophilic granuloma (Langerhans cell histiocytosis); however, vertebra plana may also be caused by a range of other conditions. We sought to determine whether vertebra plana can be associated with malignancies other than eosinophilic granuloma.

QUESTIONS/PURPOSES

(1) To report the underlying diagnoses for children with vertebra plana and determine how frequently these patients were found to have eosinophilic granuloma as opposed to an underlying malignant process, (2) to evaluate the occurrence of nondiagnostic results on biopsy, and (3) to determine whether the presenting characteristics of spinal lesions were associated with the ultimate clinical diagnosis.

METHODS

As part of a retrospective review, our institutional electronic medical record was searched for all patients younger than 18 years between 1976 and 2017 whose clinical record included the term vertebra plana. Patients with trauma were excluded. Twenty-seven patients met the inclusion criteria (mean [range] age 9 years [0 to 18]; 12 girls). To address our first research purpose about the underlying diagnoses of patients with vertebra plana, we reviewed the final clinical diagnosis. To address our second research purpose about the utility of biopsy, we reviewed which patients underwent a biopsy and whether it had been diagnostic. To address our third research purpose about the radiographic criteria, we classified the radiographs and compared this to the clinical diagnosis. Vertebral collapse was described as less than 50% collapse, 50% to 100% collapse, symmetrical, and asymmetrical. The location of each lesion was noted.

RESULTS

Twelve of 27 patients had a diagnosis of eosinophilic granuloma. Six of 27 had other neoplastic etiologies, including acute lymphoblastic leukemia, primary germ cell tumor, giant cell tumor, rhabdomyosarcoma and teratoma. Seventeen of 27 patients underwent biopsy to confirm the diagnosis; six biopsies were consistent with eosinophilic granuloma, six for other etiologies, and five were nondiagnostic. With the limited patient numbers available, there was no difference in the frequency of less than 50% loss of height or 50% to 100%, or symmetric and asymmetric loss of height, and location of the lesion among patients with eosinophilic granuloma and those with other diagnoses.

CONCLUSIONS

Eosinophilic granuloma or Langerhans cell histiocytosis is a common cause of vertebra plana, but other causes must be considered in children presenting with this radiographic finding. Six of 27 of patients presenting to our center with vertebra plana had an underlying neoplasm other than eosinophilic granuloma. With the limited patient numbers available, pain, spinal location, and the degree and symmetry of collapse were not associated with a diagnosis of eosinophilic granuloma in this series. Thus, patients presenting with vertebral plana and back pain need a comprehensive work-up and potentially tissue biopsy to determine diagnosis and appropriate treatment.

LEVEL OF EVIDENCE

Level IV, diagnostic study.

Localized Chronic Form of Langerhans Cell Histiocytosis in the Femur of a 16-Year-Old Male Successfully Treated with Radiofrequency Ablation

Only three cases of patients suffering from a localized chronic form of Langerhans cell histiocytosis (LCH) successfully treated with radiofrequency ablation (RFA) have been published so far. This is the first case report of a patient with a localized chronic form of LCH of the femur, which was successfully treated with percutaneous image-guided RFA, and who was evaluated pre-RFA and followed up post-RFA for a period of 48 months, in order to validate the safety and efficacy of this method and to obtain imaging studies depicting the actual in situ changes taking place post-RFA. RFA was proved to be a safe and efficient method when treating patients with a localized chronic form of LCH.

Eosinophilic Granuloma of the Thumb Presenting in a 4-Month-Old Child: Case Report and Review of the Literature

Eosinophilic granuloma (EG) is a benign bone tumor of unknown origin usually seen in children. It is typically found in flat and long bones of the skull and of the appendicular skeleton, respectively. Small bones are rarely affected. The diagnosis and treatment of EG can be challenging as differential diagnosis includes several disorders that can cause osteolytic lesions. Moreover, surgical treatment can be difficult due to the small size of the bone and surrounding structures. Here we describe a case of EG of the proximal phalanx of the thumb (P1 D1) presenting in a 4-month-old boy with persistent swelling and limited range-of-motion of the interphalangeal joint in the left thumb. Over a 6-year follow-up, no sign of relapse was observed. Moreover, the curetted bone did regenerate, and it appeared homogenously dense as normal trabecular bone on the last plain radiographs; the patient was symptom-free at the last follow-up visit. Clinical presentation, treatment, pathoanatomy, localization, and complication of this form of tumor are discussed, and all previously reported cases are reviewed to give a more comprehensive picture of EG of the hand and fingers.

Cone Beam CT study of a case of eosinophilic granuloma of the mandible in a young patient

Eosinophilic granuloma (EG) is a rare bony disease deriving from abnormal proliferation of histiocytes, and is the most common form of presentation of Langerhans cell histiocytosis. EG predominantly affects the axial skeleton. However, when localised in the head and neck district, mandibular lesions account for the majority of cases. Mandibular lesions can mimic other pathological conditions, making biopsy fundamental for differential diagnosis. Treatment depends on the severity of the disease, ranging from pharmacological treatment to surgical approach. However, EG is also reported to possibly undergo spontaneous resolution. In this case report, we describe a rare case of EG with particularly aggressive behaviour in a young patient. Initially, local pharmacological treatment with intralesional administration of corticosteroids lead to worsening of the symptoms, increase in lesion's dimensions, and disruption of the cortical bone. A more invasive therapeutic approach involving radical surgery was then performed, with consequent resolution of the disease.

Bone tumours of the clavicle: Histopathological, anatomical and epidemiological analysis of 113 cases

Backround

This retrospective study aimed to determine the frequency of bone tumours of the clavicle and their histopathological, anatomical and epidemiological characteristics in a large case series.

Methods

The records of 327 lesions of the clavicle collected from 1976 to 2018 in our bone tumour registry and institute of pathology were reviewed. Following data were evaluated: age, gender, side, radiological assessment, tumour location within the clavicle, and histopathological findings.

Results

Bone tumours were detected in 113 patients with a mean age of 40 years. The lateral third of the clavicle was most frequently involved. Analysis revealed 22 benign, 31 intermediate, and 60 malignant tumours. Eosinophilic granuloma was the most commonly found neoplasm (18.6%), followed by bone metastases (15.0%), Plasma cell myeloma (8.8%), Ewing sarcoma (8.8%), and Osteosarcoma (8.0%). 53% of the tumours were malignant. Mean age was 51 years in the malignant tumour group and 28 years in patients with a benign/intermediate lesion (p < 0.001).

Conclusions

The high incidence of malignant bone tumours of the clavicle found in this study highlight the importance of biopsy to prevent delay in diagnosis and treatment of these lesions, especially in patients with increased age. We believe that the results of this study are of clinical importance and may aid the physician in the management of these rare lesions.

Oral lymphoid lesions: a 47-year clinicopathological study in a Brazilian population

We performed an epidemiological, clinical and histopathological analysis of oral lymphoid lesions (OLLs) during a 47-year period. Data regarding patient age, sex, duration, location, symptomatology, type of growth, implantation, staining, presence of ulceration and bleeding of all cases were compiled from the clinical data. For the histopathological analyses, all slides stained by H/E were reassessed. During the analyzed period, 14,565 patients with oral and maxillofacial lesions were diagnosed, with 45 cases diagnosed as OLLs. The most prevalent location was the tongue. Females were more affected, and the mean age was 40.8 years. OLLs presented a heterogeneous frequency, with the prevalence of reactive lesions (42.3%) followed by developmental lesions (35.6%). Among the reactive lesions, foreign body granulomas were the most common. Regarding diagnosed neoplasms, malignant represented 13.2% of the cases. The average time of evolution of OLLs in general was of 22.2 months. Regarding the histopathological characteristics, the presence of primary lymphoid follicles was observed in 37.8% of the cases, while inflammatory infiltrates were diffuse in 66.7% and epimyoepithelial islands were observed in 13.3%. Our study concludes that OLLs involves a broad spectrum of lesions that share the presence of the lymphoid component, which can range from indolent to more aggressive behavior.

[Diagnostics and treatment of benign spinal tumors]

Benign tumors of the spine are rare and may lead to unspecific back pain. The classification of the lesion is typically achieved with a combination of imaging techniques (MRI and CT scans) and, in some cases, a histological sampling to allow differentiation from malignant processes. Both open and interventional (CT guided) biopsies are possible, depending on the localization of the tumor. Treatment strategies are diverse, require an interdisciplinary approach, and include operative and interventional procedures. The following article gives an overview of the most important benign tumors of the spine, the typical features in imaging, and treatment strategies.