Langerhans cell histiocytosis

Neoplastic and Non-neoplastic Bone Lesions of the Knee

Numerous anatomical variants are described around the knee, many of which look like bony lesions, so it is important to know them to avoid unnecessary complementary tests and inadequate management. Likewise, several alterations in relation to normal development can also simulate bone lesions.However, numerous pathologic processes frequently affect the knee, including traumatic, inflammatory, infectious, and tumor pathology. Many of these entities show typical radiologic features that facilitate their diagnosis. In other cases, a correct differential diagnosis is necessary for proper clinical management.Despite the availability of increasingly advanced imaging techniques, plain radiography is still the technique of choice in the initial study of many of these pathologies. This article reviews the radiologic characteristics of tumor and nontumor lesions that may appear around the knee to make a correct diagnosis and avoid unnecessary complementary radiologic examinations and inadequate clinical management.

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.

Mastoiditis in a Patient With Seizures

A 64-year-old man with a 2-year history of seizure disorder presented to the emergency department at an outside hospital with breakthrough seizures. What is your diagnosis?

Posterior pedicle screw fixation combined with local steroid injections for treating axial eosinophilic granulomas and atlantoaxial dislocation: A case report

BACKGROUND

Eosinophilic granuloma (EG) is a proliferative condition that affects the cells of bone tissue. There are no specific clinical signs or imaging manifestations in the early stages of the disease, making it simple to overlook and misdiagnose. Because of the disease's rarity, there is presently no standardized treatment principle. There are few accounts of such occurrences affecting the axis among children. We discovered a case of a child whose EG resulted in atlantoaxial joint dislocation and destruction of the axial bone.

CASE SUMMARY

After having pharyngeal discomfort for more than six months without a clear explanation, a 6-year-old boy was brought to our hospital. Following a careful evaluation, the pathology indicated a strong likelihood of an axial EG. Ultimately, we decided to treat the boy with posterior pedicle screw fixation and local steroid injections.

CONCLUSION

EGs of the upper cervical spine are quite uncommon in children, and they are exceedingly easy to overlook or misdiagnose. Posterior pedicle screw fixation and local steroid injections are effective treatments for patients with axial EGs affecting the atlantoaxial junction.

Eosinophilic granuloma of the clavicle in an 11-year-old Chinese girl: A case report

RATIONALE

Eosinophilic granuloma (EG) - the most common form of Langerhans cell histiocytosis - occurs rarely, and manifestations with only rib and clavicle involvement are extremely rare. EG symptoms often include pain, swelling, and soft tissue mass. The clinical diagnosis of bone EG is complex, and the differential diagnosis includes Ewing sarcoma, tuberculosis, multiple myeloma, lymphoma, primary bone malignancy, and other osteolytic lesions.

PATIENTS CONCERN

The patient was an 11-year-old female who found a subcutaneous mass at the junction of the right clavicle and sternum 2 days before presenting at the clinic without apparent triggers. Initially, we considered a subcutaneous cyst or inflammatory mass. Color ultrasound and computed tomography examination revealed osteomyelitis. Finally, the patient was diagnosed with EG after a pathological tissue biopsy, and the child recovered after surgery and anti-infective treatment.

DIAGNOSIS

The patient underwent surgery to remove the tumor at a specialist hospital and was diagnosed with EG by pathological examination.

INTERVENTION

The patient went to a specialist hospital for surgery to remove the mass and underwent anti-infective treatment.

OUTCOMES

The patient recovered after surgical resection and antibiotic treatment.

LESSONS

In this report, we emphasize that the clinical presentation of EG in children is not specific. Furthermore, examining age, history, presence of symptoms, and the number of sites is essential to make a correct diagnosis, and a histological examination is necessary to confirm the diagnosis.

Osteofibrous dysplasia: A rare case in 3-day-old female

Osteofibrous dysplasia (OFD) is a nonneoplastic tumor-like lesion, made up of fibrous matrix with immature bone tissue surrounded by osteoblasts, occurring usually in the cortex of tibial diaphysis. OFD is usually seen in the first decade of life and, according to literature, it is rarely seen in the newborn period. Diagnosis of congenital OFD in the newborn is challenging because it is uncommon in this age group and can be confused with other bone benign or malignant lesions. Imaging plays an important role in diagnosis, although histological confirmation is often required. Our report presents a rare case of pathologically confirmed congenital OFD in 3-day-old female which presented with a swelling of her right leg. We will focus on imaging findings of OFD and main differential diagnosis of this lesion in neonatal age.

Solitary long-bone epiphyseal lesions in children: radiologic-pathological correlation and epidemiology

BACKGROUND

Solitary epiphyseal lesions are rare and present with nonspecific imaging features. Knowledge regarding etiologies of pediatric epiphyseal lesions is limited to small studies.

OBJECTIVE

The purpose of this study was to determine the relative incidence of pathologies affecting the pediatric epiphysis based on biopsy-proven cases with imaging.

MATERIALS AND METHODS

We conducted a retrospective review of imaging studies including the terms "biopsy" or "resection" and entities known to affect the epiphysis and cross-referenced these with pathology reports, recording the relevant clinical data. Two radiologists performed comprehensive imaging review and recorded relevant features.

RESULTS

Forty-nine children and adolescents met inclusion criteria. The long-bone epiphyseal lesion etiologies included chondroblastoma (n=22, 45%), nonspecific nonmalignant pathology (n=11, 22%), osteomyelitis (n=9, 18%), lymphoma (n=2, 4%) and 1 case of each of aneurysmal bone cyst, chondrosarcoma, enchondroma, hemangioendothelioma, and non-Langerhans cell histiocytosis. Median age was 13.1 years old (range 1.5-18.6 years). We performed comparative analysis of the two most common lesions in our series, chondroblastoma and osteomyelitis. Chondroblastoma was significantly more likely to be peripherally located (94% vs. 33%, P=0.002) and to demonstrate a discrete T1-weighted hypointense rim (94% vs. 33%, P=0.002); there were no significant differences in enhancement or intrinsic signal properties. Children with chondroblastoma were older (15.1 years vs. 7.3 years, P=0.001), and chondroblastoma lesions were significantly larger, with mean maximum lesion diameter of 25 mm (interquartile range [IQR] 20-30) vs. 12 mm (IQR 11-18) (P=0.001) and lesion volumes of 4.4 mL (IQR 2.4-7.9) vs. 0.4 mL (IQR 0.2-1.4) (P=0.01).

CONCLUSION

This study reports the relative frequency of pathology of pediatric solitary epiphyseal lesions and describes several features that might assist in differentiating between chondroblastoma and osteomyelitis.

Langerhans cell histiocytosis: A case report with oral manifestations and the role of pediatric dentists in the diagnosis

Langerhans cell histiocytosis (LCH) is a benign disease that behaves malignantly. Early recognition and treatment of oral manifestation of LCH by pediatric dentist and other medical specialties is important to prevent further organ damage.

Suggested Case of Langerhans Cell Histiocytosis in a Cretaceous dinosaur

Susceptibility to diseases is common to humans and dinosaurs. Since much of the biological history of every living creature is shaped by its diseases, recognizing them in fossilized bone can furnish us with important information on dinosaurs' physiology and anatomy, as well as on their daily activities and surrounding environment. In the present study, we examined the vertebrae of two humans from skeletal collections with Langerhans Cell Histiocytosis (LCH), a benign osteolytic tumor-like disorder involving mainly the skeleton; they were diagnosed in life, along with two hadrosaur vertebrae with an apparent lesion. Macroscopic and microscopic analyses of the hadrosaur vertebrae were compared to human LCH and to other pathologies observed via an extensive pathological survey of a human skeletal collection, as well as a three-dimensional reconstruction of the lesion and its associated blood vessels from a µCT scan. The hadrosaur pathology findings were indistinguishable from those of humans with LCH, supporting that diagnosis. This report suggests that hadrosaurids had suffered from larger variety of pathologies than previously reported. Furthermore, it seems that LCH may be independent of phylogeny.

Secondary aneurysmal bone cysts and associated primary lesions: imaging features of 49 cases

PURPOSE

To describe the imaging, anatomic, and clinical features of a series of secondary aneurysmal bone cysts (ABC) and to ascertain their most commonly associated primary bone lesions.

METHODS

Forty-nine cases of histopathologically proven secondary ABCs were retrospectively reviewed. Demographic data and clinical history were obtained. Radiographic, computed tomographic, magnetic resonance, and nuclear medicine imaging were analyzed. Lesion location, imaging characteristics, and associated primary lesions were documented. Linear regression analysis and Chi-squared testing was performed for statistical analysis.

RESULTS

Twenty-four males and 25 females were included, with an age range of 8-79 years (mean 29.7 + - 4.5 years). Eleven types of primary bone lesion were identified, with giant-cell tumor (n = 17, 35%), chondroblastoma (n = 11, 22%), fibrous dysplasia (n = 6, 12%), osteoblastoma (n = 4, 8%) and osteosarcoma (n = 4, 8%) being the most frequent. The lesions involved chiefly the long bone epiphyses (n = 25, 51%). Secondary ABC imaging findings and locations most closely approximated those of their primary counterparts, although fluid-fluid levels were seen at a higher frequency than previously reported in primary chondroblastoma (9/11, 82%), fibrous dysplasia (2/6, 33%), osteoblastoma (4/4, 100%), osteosarcoma (3/4, 75%), and chondromyxoid fibroma (1/2, 50%).

CONCLUSION

The most common primary lesions associated with secondary ABC were giant cell tumor and chondroblastoma, located in the long bone epiphyses. The majority of the secondary ABCs demonstrate predominant imaging characteristics typical of the primary bone lesions, but with a higher presence of fluid-fluid levels.

Langerhans cell histiocytosis presenting as eosinophilic granuloma of the bilateral forearms in an 8-year-old girl: a case report

Background

Langerhans cell histiocytosis previously known as histiocytosis X is a rare disease of children and young adults with a very broad clinical spectrum. In children, its annual incidence is estimated between 0.2–0.5 per 100,000.

Case representation

An 8-year-old Moroccan girl with no known personal or family history presented to our institution with painful swelling of both forearms. An X-ray and magnetic resonance imaging were inconclusive. We then performed a biopsy curettage (of her left forearm). Microscopic analysis followed by immunohistochemical analysis disclosed a diagnosis of Langerhans cell histiocytosis. No chemotherapy was necessary. Clinical and radiological improvement was achieved after 6 months.

Conclusion

The particularity of this observation is the bilaterality of the lesion on both forearms and it has not previously been reported. Langerhans cell histiocytosis should be included in the differential diagnosis of osteomyelitis and Ewing’s sarcoma.

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

BACKGROUND

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

CASE DESCRIPTION

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

CONCLUSIONS

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

Radiological review of skull lesions

Abstract

Calvarial lesions are often asymptomatic and are usually discovered incidentally during computed tomography or magnetic resonance imaging of the brain. Calvarial lesions can be benign or malignant. Although the majority of skull lesions are benign, it is important to be familiar with their imaging characteristics and to recognise those with malignant features where more aggressive management is needed. Clinical information such as the age of the patient, as well as the patient’s history is fundamental in making the correct diagnosis. In this article, we will review the imaging features of both common and uncommon calvarial lesions, as well as mimics of these lesions found in clinical practice.

Teaching Points

• Skull lesions are usually discovered incidentally; they can be benign or malignant.

• Metastases are the most frequent cause of skull lesions.

• Metastatic lesions are most commonly due to breast cancer in adults and neuroblastoma in children.

• Multiple myeloma presents as the classic “punched out” lytic lesions on radiographs.

• Eosinophilic granuloma is an osteolytic lesion with bevelled edges.

Bone metabolism in Langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH) is a rare disease of not well-defined etiology that involves immune cell activation and frequently affects the skeleton. Bone involvement in LCH usually presents in the form of osteolytic lesions along with low bone mineral density. Various molecules involved in bone metabolism are implicated in the pathogenesis of LCH or may be affected during the course of the disease, including interleukins (ILs), tumor necrosis factor α, receptor activator of NF-κB (RANK) and its soluble ligand RANKL, osteoprotegerin (OPG), periostin and sclerostin. Among them IL-17A, periostin and RANKL have been proposed as potential serum biomarkers for LCH, particularly as the interaction between RANK, RANKL and OPG not only regulates bone homeostasis through its effects on the osteoclasts but also affects the activation and survival of immune cells. Significant changes in circulating and lesional RANKL levels have been observed in LCH patients irrespective of bone involvement. Standard LCH management includes local or systematic administration of corticosteroids and chemotherapy. Given the implication of RANK, RANKL and OPG in the pathogenesis of the disease and the osteolytic nature of bone lesions, agents aiming at inhibiting the RANKL pathway and/or osteoclastic activation, such as bisphosphonates and denosumab, may have a role in the therapeutic approach of LCH although further clinical investigation is warranted.

Reconstruction of a severe mandibular pathological fracture caused by Langerhans cell histiocytosis using a free fibula osteocutaneous flap:a case report

Langerhans cell histiocytosis (LCH) is a rare disease in which Langerhans cells, which are bone marrow-derived antigen-presenting cells, proliferate in single or multiple organs. We successfully treated a patient with unifocal LCH of the mandible with malocclusion due to a severe pathological fracture, using reconstruction with a vascularised free bone.

Clinical course of the bony lesion of single-system single-site Langerhans cell histiocytosis - Is appropriate follow-up sufficient treatment?

BACKGROUND

Langerhans cell histiocytosis (LCH) is categorized into three types, which include single-system single-site (SS-s), single-system multiple-site (SS-m) and multisystem (MS). The most commonly affected site in LCH is bone, and the bony lesion of SS-s LCH has a good prognosis. The bony lesion of SS-s LCH has been thought to regress spontaneously. Although treatments such as curettage, direct injection of corticosteroids, and chemotherapy have been performed, regular follow-up is the first line of treatment for the bony lesion of SS-s LCH. For preventing orthopedic sequelae, strict and appropriate follow-up should be performed, but the appropriate period and method of follow-up has not yet been established.

METHODS

In the present study, we retrospectively analyzed a series of 7 cases of patients with SS-s LCH with a bony lesion treated in the Department of Orthopedic Surgery at Kagoshima University Hospital (Kagoshima, Japan) from 2006 to 2015.

RESULTS

The bony lesion regressed spontaneously in all patients. Factors such as location, size, preoperative C-reactive protein (CRP) value, standardized uptake (SUV) value of positron emission tomography (PET), age, sex and direct steroid injection were not related to the clinical course. Temporary expansion of the lesion occurred in 3 patients and a temporary worsening of pain occurred in 1 patient during the follow-up period. These events occurred within 6 weeks after biopsy.

CONCLUSION

Careful follow-up and the use of an appropriate orthosis can lead to a good clinical course for the bony lesion of SS-s LCH. Future research should seek to determine the appropriate follow-up period.

Atlantoaxial Langerhans cell histiocytosis radiographic characteristics and corresponding prognosis analysis

BACKGROUND

Langerhans cell histiocytosis (LCH) may affect atlas and axis, and there were very few published cases describing a characteristic of LCH of atlantoaxial.

OBJECTIVE

The objective of the study is to investigate the image manifestations of atlantoaxial LCH to improve the in-depth comprehension on it.

MATERIALS AND METHODS

A retrospective study was done of computed tomography (CT) and magnetic resonance imaging in atlas and axis and prognosis was analyzed.

RESULTS

The study included 41 patients (average age 12.9 years and median age 8 years) diagnosed with LCH, with 75.6% under 15 years old. Eighty-four lesions of LCH were identified including 47 in the atlas and 37 in the axis. The osteolytic bone destructions in the atlas and axis were characterized, 22% accompanied by sclerotic margins. Thirteen patients had a compression fracture, 11 in the lateral mass of the atlas and 2 in the C2 vertebral body. Sixteen and three patients had atlantoaxial malalignment and dislocation, respectively. On T2-weighted images, 68.9% showed iso- or low-signal intensity, 27.6% showed hyperintensity signal, and 3.4% showed heterogeneous signal. On postcontrast images, 81.9% showed significant enhancement, 12.5% showed moderate enhancement, and 6.3% showed mild enhancement. CT reexamination of 14 patients indicated atlantoaxial bone destruction relatively repaired in 12 patients. Thirty-three patients were a follow-up, 81.8% had no significant symptoms and 18.2% with remaining symptoms.

CONCLUSIONS

The atlas and axis were affected by LCH, mainly in children. The lateral mass was easily affected and compressed, destruction of the atlas and axis could lead to atlantoaxial joint instability. The prognosis was good in most of the patients.

Eosinophilic granuloma at the cerebellopontine angle in an adult; a rare case report and literature review

INTRODUCTION

Langerhans cell histiocytosis (LCH) is a rare immunologic disorder, identified by immature proliferation of histiocytes which may present as systemic or focal lesions. Eosinophilic granuloma (EG) is localized from of LCH mainly involving bones such as skull, femur, spine, ribs, mandible and pelvis. Cerebello-pontine (CP) angle is a rare anatomic location for involvement by EG.

PRESENTATION OF CASE

A 32 year old man was being evaluated in our neuro-oncology clinic due to diplopia since 4 months ago. On physical examination he had left sided abducens paresis, hyposthesia over left half of his face and a decreased corneal reflex on left side. A magnetic resonance imaging (MRI) study revealed a lesion at left CP angle measuring 30×25×25mm in size which was isointense in T1, hypointense on T2 with homogenous enhancement in post-contrast study. A standard retrosigmoid approach was carried out for resection of this lesion. Pathology report of the frozen section depicted infiltration of eosinophils and large mono-nuclear cells. The infiltrative nature of the lesion encouraged us not to attempt further resection. Permanent pathology report was in favor of EG. Patient was referred to an oncology clinic for proceeding with the steroid therapy.

DISCUSSION

To the best of authors' knowledge, this is the first report of EG at CP angle in an adult, in the literature. Infiltration of eosinophils and positivity for CD1a and S-100 renders the diagnosis unmistakable.

CONCLUSION

When the diagnosis is suggestive of EG, incompletely excised lesions can be further managed by steroid therapy.

A rare case of solitary brain Langerhans cell histiocytosis with intratumoral hemorrhage in a patient affected by Turner syndrome

Background:

Langerhans cell histiocytosis (LCH) is a rare disease involving clonal proliferation of cells with characteristics similar to bone marrow-derived Langerhans cells. The case of a young woman, affected by Turner syndrome and a solitary intraparenchymal LCH associated with an osteolytic lesion of the overlying skull, is presented.

Case Description:

The patient, with an insidious history of headache and a growing soft mass in the left frontal region, presented with a sudden generalized tonic-clonic epileptic seizure. Neuroradiological investigations showed an osteolytic lesion of the left frontal bone and an underlying brain lesion associated with recent signs of bleeding. The patient was operated on with a complete removal of the lesion. The postoperative course was uneventful.

Conclusions:

The clinical, neuroradiological, and intraoperative findings are presented, along with a review of the literature. Although rare, LCH should be considered in the differential diagnosis when a scalp lesion occurs with a progressive growing.

Skull Vault Lesions: A Review

OBJECTIVE

The aim of this article is to describe the imaging features of the most common benign or malignant skull vault lesions, which may be focal, multifocal, or diffuse.

CONCLUSION

Imaging features, in association with the age, history, and clinical symptoms of the patient, make it possible to propose a course of action: simple survey, pathologic confirmation, or complete surgical resection.

Langerhans cell histiocytosis of the clavicle: a case report and review of the literature

We report a rare case of solitary Langerhans cell histiocytosis (LCH) involving the clavicle of an adult female. The patient was a 32-year-old female presenting with 1 month history of progressive pain, swelling, and tenderness in the region near the left sternoclavicular joint. Radiograph, computed tomography, and magnetic resonance imaging showed an osteolytic lesion in the clavicle with tumor extension and soft tissue edema. Surgical curettage of the lesion was performed, and the histopathologic diagnosis was LCH. Because of its rarity and possibly variable presentation, LCH should be included and considered in the differential diagnosis when we encounter a clavicle lesion.

Eosinophilic granuloma of the sternum in a child treated with closed biopsy

Langerhans cell histiocytosis is a rare neoplastic proliferative disorder of the Langerhans cells. The clinical course is variable, ranging from a low symptomatic single bone lesion to fatal multiple organ involvement. Rarely, the sternum can be the first and single location of the disease. We report on a 12-year-old boy who presented with an aggressive lytic lesion of the proximal sternum associated with local pain and afternoon fever. Histopathological analysis of the closed biopsy specimen indicated eosinophilic granuloma of bone/Langerhans cell histiocytosis. Soon after the biopsy procedure the pain and fever subsided. Computed tomography at 2 months showed healing of the lytic lesion. The patient received no other type of treatment. At 2 year follow up he was symptom and disease free.

Langerhans cell histiocytosis in the jugular foramen

Langerhans cell histiocytosis (LCH) is a rare disease of neoplastic proliferation of monocyte-macrophage system. Although LCH can affect almost any organ, solitary involvement of jugular foramen is extremely rare and can present a diagnostic dilemma because of its rarity at this location. Here, we present the case of an adult patient with LCH affecting the jugular foramen, and review the relevant literature.

Soft tissue Langerhans cell histiocytosis with secondary bone involvement in extremities: evolution of lesions in two patients

Langerhans cell histiocytosis (LCH) is an uncommon disorder of unknown etiology with a wide spectrum of biological behavior. The most common sites of involvement are bone, skin, and lung. While osseous LCH can result in secondary soft tissue involvement, primary soft tissue LCH in extremities with secondary bone involvement is rare, and little is known about its natural course. We report two adult patients with multi-organ system LCH who had primary soft tissue lesions with secondary involvement of adjoining bones in lower extremities, and illustrate the important role played by various imaging modalities in detection and monitoring of treatment response. We also document spontaneous clinical resolution of LCH lesions without therapy, and positive response of these lesions to chemotherapy.

Langerhans cell histiocytosis followed by Hodgkin's lymphoma

A 22-year-old man was referred to our institution due to lower back pain and was diagnosed with Langerhans cell histiocytosis of the thoracic and lumbar spine. The patient achieved complete remission with radiotherapy and chemotherapy. One year later, right cervical lymphadenopathy was observed and Hodgkin's lymphoma was confirmed on biopsy. The patient was treated with chemotherapy and autologous stem cell transplantation, and experienced no further symptoms. Further, no evidence of recurrence was observed on follow-up imaging. This report discusses the association between Langerhans cell histiocytosis and Hodgkin's lymphoma.

The diagnostic value of 18F-FDG PET and MRI in paediatric histiocytosis

PURPOSE

To analyse the diagnostic value of (18)F-FDG PET and MRI for the evaluation of active lesions in paediatric Langerhans cell histiocytosis.

METHODS

We compared 21 (18)F-FDG PET scans with 21 MRI scans (mean time interval 17 days) in 15 patients (11 male, 4 female, age range 4 months to 19 years) with biopsy-proven histiocytosis. Primary criteria for the lesion-based analysis were signs of vital histiocyte infiltrates (bone marrow oedema and contrast enhancement for MRI; SUV greater than the mean SUV of the right liver lobe for PET). PET and MR images were analysed separately and side-by-side. The results were validated by biopsy or follow-up scans after more than 6 months.

RESULTS

Of 53 lesions evaluated, 13 were confirmed by histology and 40 on follow-up investigations. The sensitivity and specificity of PET were 67 % and 76 % and of MRI were 81 % and 47 %, respectively. MRI showed seven false-positive bone lesions after successful chemotherapy. PET showed five false-negative small bone lesions, one false-negative lesion of the skull and three false-negative findings for intracerebral involvement. PET showed one false-positive lesion in the lymphoid tissue of the head and neck region and two false-positive bone lesions after treatment. Combined PET/MR analysis decreased the number of false-negative findings on primary staging, whereas no advantage over PET alone was seen in terms of false-positive or false-negative results on follow-up.

CONCLUSION

Our retrospective analysis suggests a pivotal role of (18)F-FDG PET in lesion follow-up due to a lower number of false-positive findings after chemotherapy. MRI showed a higher sensitivity and is indispensable for primary staging, evaluation of brain involvement and biopsy planning. Combined MRI/PET analysis improved sensitivity by decreasing the false-negative rate during primary staging indicating a future role of simultaneous whole-body PET/MRI for primary investigation of paediatric histiocytosis.

Extracranial skeletal Langerhans cell histiocytosis: MR imaging features according to the radiologic evolutional phases

PURPOSE

The purpose was to describe the magnetic resonance (MR) findings of extracranial skeletal Langerhans cell histiocytosis according to the radiologic evolutional phases.

MATERIALS AND METHODS

Twenty-two patients with pathologically confirmed extracranial skeletal Langerhans cell histiocytosis were included. The lesions were classified as early, mid, and late phases according to the radiologic evolutional phases. MR images were retrospectively analyzed regarding signal intensity, internal hypointense band, fluid levels, periosteal reaction, adjacent bone marrow and soft tissue abnormal signal, and patterns of contrast enhancement in each phase.

RESULTS

According to the radiologic evolutional phases, there were 4 patients with early phase, 16 with mid phase, and 2 with late phase. All cases showed hypointense to intermediate signal intensity on T1-weighted images. On T2-weighted images, 12 (55%) of the 22 lesions were hyperintense, and 10 (45%) showed intermediate signal. All lesions showed diffusely heterogeneous signal on T2-weighted images. Internal low-signal bands of the lesions were observed in 13 cases (59%). There were two cases with fluid levels in mid phase. Periosteal reaction was observed in 13 (59%) cases. Adjacent bone marrow or soft tissue abnormal signal was observed in 20 cases (91%), respectively. According to early, mid, and late phases, bone marrow and soft tissue abnormal signals were observed in 100%, 100%, and 0% cases, respectively. Soft tissue mass was seen in eight cases (36%). Ten (46%) lesions showed cortical destruction, including one patient with a pathologic fracture. Among 21 patients with contrast infusion, diffuse enhancement was observed in 19 patients (90%), and marginal and septal enhancement was seen in 2 patients (10%).

CONCLUSION

MR imaging was helpful in the diagnosis of extracranial skeletal Langerhans cell histiocytosis, particularly in early and mid phases.

Diabetes insipidus associated with a thickened pituitary stalk in a case of Langerhans Cell Histiocytosis

Diabetes insipidus (DI) associated with a thickened pituitary stalk is a diagnostic challenge in the pediatric population. Langerhans Cell Histiocytosis (LCH) is a rare cause of this entity. A 4-year-old male child presented with central DI of 1-year duration, associated with a thickened pituitary stalk. The etiology for the same remained elusive as the patient had no other manifestation to suggest LCH. A year later, the patient developed a left frontal scalp swelling. Neuroradiology demonstrated multiple punched out osteolytic lesions in both the frontal bones. The infundibulum was thickened and showed post-contrast enhancement. Histology and immunohistochemistry (IHC) of the biopsy specimen confirmed LCH. The child was administered chemotherapy according to LCH protocol, which resulted in 33% reduction in the size of the skull lesions. The DI was controlled with medical management. The present case highlights the need for serial follow-up and magnetic resonance (MR) imaging that led to a diagnosis of LCH. The clinical presentation and management of central DI and a thickened pituitary stalk is presented and the relevant literature is discussed.

Langerhans cell histiocytosis of the optic chiasm: case report

BACKGROUND AND IMPORTANCE

Langerhans cell histiocytosis (LCH) is an uncommon disease, usually affecting the cranium and peripheral bones. We present a rare case of isolated optic chiasm involvement by LCH to highlight the importance of considering LCH in the differential diagnosis of optic chiasm lesions.

CLINICAL PRESENTATION

A 71-year-old woman presented with a 6-week history of worsening peripheral vision, headaches, weakness, cold sensitivity, and fatigue. She was found to have dense bitemporal hemianopsia. Magnetic resonance imaging revealed a 2-cm lesion, contrast enhancing on T1 and bright on T2 signal, involving the optic chiasm but not the pituitary gland. Preoperative considerations included optic nerve glioma, choristoma of the stalk, sarcoid, hypothalamic glioma, and Langerhans cell histiocytosis. The patient underwent a right subfrontal craniotomy for biopsy of the lesion. The optic chiasm was grossly enlarged with no tissue external to the chiasm. A midline incision was made in the lamina terminalis, and multiple biopsies were taken of firm fibrous material. Histologically, the tumor was characteristic for LCH and included a mixture of histiocytes with features of Langerhans cells, eosinophils, small lymphocytes, macrophages, neutrophils, and plasma cells.

CONCLUSION

LCH is a rare disease, generally affecting bone, skin, lymph nodes, and in more severe cases, visceral organs. LCH involving the optic pathways is a rare condition that should be included in the differential for adults with mass lesions involving the orbit, eye, optic nerve, or chiasm. Future clinical and basic science research is needed to better understand LCH, its molecular origin, and its growth pattern.

Eosinophilic granuloma of bilateral humerus with unusual diagnostic process

A 15-year-old boy presented with a right shoulder pain and the inability to use his right upper limb after carrying a heavy object. Physical examination and local imaging revealed a benign tumor or tumor-like lesion in the upper ends of both humeri and a pathologic fracture in the right humerus. An initial biopsy was reported as fibroblastic osteosarcoma. But the CT-guided biopsy was diagnosed as eosinophilic granuloma (EG). Bone curretage and grafting confirmed diagnosis of EG. This case illustrates the importance of combining a clinical impression with imaging and pathology in bone and soft tissue tumors.

Multifocal Langerhans cell histiocytosis with infiltrative pelvic lesions: PET/CT imaging

Langerhans cell histiocytosis is essentially a pediatric disorder with a large spectrum encompassing focal lytic osseous eosinophilic granuloma, chronic multifocal Hand-Schuller-Christian lesions, and fulminant disseminated Letterer-Siwe syndrome. However, adult involvement is not uncommon. The authors present a case of multifocal Langerhans cell histiocytosis in a 47-year-old woman. The PET/CT-depicted infiltrative features of soft tissue and osseous pelvic lesions with obstructive uropathy are unusual for this disease.

Langerhans cell histiocytosis of the parietal bone with epidural and extracranial expansion - case report and a review of the literature

Langerhans cell histiocytosis is a rare neoplasm that belongs to the histiocytic and dendritic cell neoplasm group according to the 2008 WHO classification. It has been defined as neoplastic proliferation of Langerhans cells that express CD1a and S-100 proteins and have Birbeck granules on the ultrastructural examination. Clinical presentation and behaviour are heterogeneous and can range from a solitary lytic bone lesion with a favourable course to a fatal disseminated leukaemia-like form, with a wide spectrum of intermediate clinical presentations between these two extremes. Here, we present a case report of a solitary calvarial lesion in an adolescent boy along with a review of the literature. Presenting features, initial diagnostic evaluation and treatment protocol of a unifocal monosystemic calvarial location of LCH are presented.

Langerhans cell histiocytosis with multiple spinal involvement

To stress the clinical and radiologic presentation and treatment outcome of Langerhans cell histiocytosis (LCH) with multiple spinal involvements. A total of 42 cases with spinal LCH were reviewed in our hospital and 5 had multifocal spinal lesions. Multiple spinal LCH has been reported in 50 cases in the literature. All cases including ours were analyzed concerning age, sex, clinical and radiologic presentation, therapy and outcome. Of our five cases, three had neurological symptom, four soft tissue involvement and three had posterior arch extension. Compiling data from the eight largest case series of the spinal LCH reveals that 27.2% multiple vertebrae lesions. In these 55 cases, there were 26 female and 29 male with the mean age of 7.4 years (range 0.2-37). A total of 182 vertebrae were involved including 28.0% in the cervical spine, 47.8% in thoracic and 24.2% in the lumbar spine. Extraspinal LCH lesion was documented in 54.2% cases, visceral involvement in 31.1% and vertebra plana in 50% cases. Paravertebral and epidural extension were not documented in most cases. Pathological diagnosis was achieved in 47 cases including 8 open spine biopsy. The treatment strategy varied depending on different hospitals. One patient died, two had recurrence and the others had no evidence of the disease with an average of 7.2 years (range 1-21) of follow-up. Asymptomatic spinal lesions could be simply observed with or without bracing and chemotherapy is justified for multiple lesions. Surgical decompression should be reserved for the uncommon cases in which neurologic compromise does not respond to radiotherapy or progresses too rapidly for radiotherapy.

The role of dendritic cells in mycobacterium-induced granulomas

The presence of dendritic cells (DCs) in mycobacterium-containing granulomas, as well as in other granuloma-inducing diseases, is beginning to be appreciated. This review will summarize what is known about DCs with regards to the granuloma and discuss the potential roles DCs may be playing during mycobacterial infection. Potential functions may include mycobacterial dissemination from lesions or sampling of granuloma-containing mycobacterial antigens and migration to the draining lymph nodes to maintain continuous T cell priming. Additionally, the review will discuss the potential outcomes of DC-T cell cross-talk within the granuloma and whether it results in boosting the effector functions of newly arrived T cells or anergizing systemic T cells locally. Understanding the DCs complex and changing role during this critical stage may help explain how latency is achieved and maintained. Such knowledge might also lead to improved vaccination strategies.

Langerhans cell histiocytosis of the cervical spine: a single Chinese institution experience with thirty cases

STUDY DESIGN

A retrospective study of cervical Langerhans cell histiocytosis (LCH).

OBJECTIVE

To evaluate the safety and efficiency of the present diagnosis and treatment strategy.

SUMMARY OF BACKGROUND DATA

The diagnosis and treatment protocols are still controversial for the rarity of cervical LCH.

METHODS

Thirty patients with cervical LCH were diagnosed in the past 10 years. Biopsy was routinely performed to establish the final diagnosis before treatment. Immobilization was usually the first choice. Low-dose radiotherapy was suggested for cases with solitary marked bony erosion and/or soft tissue extension, and chemotherapy for cases with multiple lesions. Surgery was preserved for suspected malignancy, neurologic deficits, severe deformity, and/or instability.

RESULTS

The mean age at diagnosis was 14.2 (range: 1.5-41) years old. Neck pain (96.7%) was the most common symptom, followed by restricted motion (70%), neurologic symptoms (36.7%), and torticollis (30%). Four cases had multiple lesions. Fourteen cases had atlantoaxial lesion and 16 cases were subaxial. The lesion extended to paravertebral soft tissue in 40% cases, to epidural space in 30%, to pedicle and/or transverse process in 56.3%. One case had endplate destruction. The accuracy of percutaneous needle biopsy under CT guidance was 91.2%. Eighteen patients had conservative treatment and 12 underwent operation. Three cases involving C2 vertebral body had fixed atlantoaxial anterior dislocation. Another 3 cases with atlantoaxial lateral mass destruction had spontaneous fusion. Eighteen patients had conservative treatment (1 only by immobilization, 13 by radiotherapy, 2 by chemotherapy, and 2 by combined chemotherapy and radiotherapy) and 12 underwent operation. All the initial symptoms were resolved, and there was no recurrence. From retrospective view, the surgical procedure might be avoided in 60% cases. Twenty-five cases had an average 61.6-month follow-up. In cases with severe bony collapse, the vertebral height ratio increased from 20.0% to 44.9% and the lateral mass height ratio from 22.2% to 56.8%.

CONCLUSION

Cervical LCH lesions often extend to paravertebral soft tissue, epidural space, pedicles, and even to the endplate and lamina. Needle biopsy under CT guidance is safe and effective. The prognosis of cervical LCH is generally fair. Conservative treatment is usually enough and surgery should be reserved for major neurologic defects like myelopathy or monoparesis.

The child with bone pain: malignancies and mimickers

Bone pain in children is common. The cause may be as benign as growing pains or as life-threatening as a malignancy. When a cause cannot be established by laboratory tests, physical examination or patient history, imaging of the affected body part is often obtained. Distinguishing benign from malignant processes involving the bones of children, based on imaging findings, can be challenging. The most common benign conditions that mimic pediatric bone tumors on imaging are Langerhan's cell histiocytosis and osteomyelitis. In this review, the current literature regarding the pathology and imaging of these conditions is reviewed. Benign conditions are compared with the most common pediatric bone tumors, Ewing sarcoma and osteosarcoma, with an emphasis on clinical and imaging features that may aid in diagnosis.

Imaging appearance of primary bony tumors and pseudo-tumors of the spine

We aim to review the imaging appearance of primary bony tumors of the spine and simulating lesions. Benign bone tumors commonly appear as well-circumscribed, slow-growing lesions with a calcified or sclerotic matrix. Malignancy is often aggressive permeative lesions with bone destruction, cortical invasion and associated soft-tissue mass. CT is an excellent imaging modality for characterization of the tumor matrix, exact location, extension and osseous changes, while MR imaging is superior for evaluation of the associated soft-tissue mass, bone marrow infiltration and intraspinal extension. There is a spectrum of pseudotumors that may also involve the spine. The imaging appearance of primary spinal bone tumor in conjunction with the patient's age, gender and lesion location allows a high percentage of correct diagnosis. Imaging plays an important role in diagnosis, characterization and extension of bone tumors of the spine which will help guide therapy.