Langerhans cell histiocytosis: presentation and evolution of radiologic findings with clinical correlation

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.

Unusual Cutaneous Location of Langheransian Histiocytosis: A Case Report

Langheransian cell histiocytosis (LCH) is a rare pathology characterized by the proliferation of CD1+ and Langerin+ cells. It can affect all ages, with an estimated prevalence of one to two cases/100,000 habitants. The involvement is often multi-visceral; however, isolated cutaneous involvement can be found in 40% of cases with very variable manifestations. We report the case of 45-year-old women followed for non-insulin-dependent diabetes and primary hyperparathyroidism suffering from isolated and refractory cutaneous histiocytosis.

Head and Neck Langerhans Cell Histiocytosis in Children

PURPOSE

Controversy exists among head and neck surgical specialties regarding management of Langerhan's Cell Histiocytosis (LCH). The purpose of this study was to evaluate diagnosis, management, and treatment outcomes in children with LCH of the head and neck.

METHODS

This is a retrospective cohort study of children with LCH of the head and neck who presented to Children's Healthcare of Atlanta hospital from 2009 to 2021. The independent variables were demographic information, lesion locations, clinical presentation, radiographic findings, diagnostic workup, treatment, and length of follow-up. The patients were grouped based on these variables. The outcome variable was disease reactivation. Descriptive statistics were calculated.

RESULTS

There were 3 presentations of LCH of the head and neck. Group 1 presented as a lesion in 1 system without CNS risk (SS-). There were 24 patients with an average age of 10 years. Lesions were located in calvaria and/or mandible. Majority of the patients were treated with only debridement. Two of the patients experienced reactivation. Group 2 presented as a lesion in 1 system with CNS risk (SS+). There were 30 patients with an average age of 6 years. Common locations were temporal bone and/or orbit. These patients present with recurrent ear infections and ptosis. Majority of the patients were treated with chemotherapy (n = 28). One patient had disease reactivation. Group 3 presented with multisystem involvement. There were 13 patients with an average age of 2 years. LCH was found in skin and the lymphatic system. Imaging demonstrated extracranial organ involvement. All of them were treated with chemotherapy. There was 40% reactivation of LCH.

CONCLUSIONS

Treatment of LCH depends on presentation. SS- subgroup can be adequately treated via surgical debridement. SS+ and multisystem groups benefit from an early disease diagnosis and require chemotherapy.

Clinical characteristics and outcomes of Langerhans cell histiocytosis at a single institution in Thailand: a 20-year retrospective study

Background

Langerhans cell histiocytosis (LCH) is a rare disease characterized by the various systems involved and clinical manifestations with a wide range of symptoms.

Objectives

To describe clinical characteristics, imaging, treatment, and outcomes of pediatric LCH at Phramongkutklao Hospital, Bangkok, Thailand.

Methods

We conducted a 20-year retrospective review of the medical records of patients diagnosed with LCH from birth to 21 years old from January 1, 1997, to December 31, 2016.

Results

In all, 14 patients with median age of 2.5 years were studied. Six (43%) patients had single-system (SS) LCH. Five patients (63%) with multisystem (MS) LCH (n = 8. 57%) had risk-organ involvement (RO+). All patients had plain X-ray imaging of their skull with 11 (79%) showing abnormal findings. Tc-99m bone imaging and fluorodeoxyglucose F18 (FDG) positron emission tomography (PET)-computed tomography (CT) demonstrated abnormal findings in 8 (89%) and 4 (29%) patients, respectively. The 5-year event-free survival (EFS) for patients with RO+ MS-LCH was less than that for those without risk-organ involvement (RO-) MS-LCH and SS-LCH (20% vs. 100%, P = 0.005). Hematological dysfunction, hypoalbuminemia, and conjugated hyperbilirubinemia may be worse prognostic factors for RO+ MS-LCH.

Conclusion

FDG-PET-CT might have a greater accuracy to detect LCH disease than conventional plain X-ray and Tc-99m bone imaging. RO+ MS-LCH has been encountered with relapse and poor outcomes. Hematopoietic involvement, hypoalbuminemia, and conjugated hyperbilirubinemia may be worse prognostic factors for RO+ MS-LCH.

Imaging of Lacrimal Gland Pathologies: A Radiological Pattern-Based Approach

Despite their unassuming size, lacrimal glands can have a variety of pathologies affecting them which often poses a diagnostic challenge clinically in view of their nonspecific presentation as palpable lump in the superolateral aspect of the orbit. There are a myriad of pathological entities ranging from inflammatory to neoplastic lesions that can affect the lacrimal glands. Cross-sectional imaging is must for the detection, characterization, and mapping of these lesions. In this pictorial review, we propose a radiological pattern-based approach for various lacrimal gland lesions that provides a working algorithm for radiologists in the evaluation of lacrimal gland pathologies.

Imaging mimics of chronic recurrent multifocal osteomyelitis: avoiding pitfalls in a diagnosis of exclusion

Chronic recurrent multifocal osteomyelitis (CRMO) is a pediatric autoinflammatory disorder that is characterized by multiple sterile inflammatory bone lesions with a relapsing and remitting course. CRMO belongs to the autoinflammatory family of rheumatologic disorders based on absence of significant titers of autoantibodies and autoreactive T-lymphocytes. In absence of pathognomonic clinical, radiographic or pathological features, diagnosis can be challenging. CRMO shares imaging features with other diseases. It is important for radiologists to be able to differentiate other diseases from CRMO because prognosis varies from completely benign to frankly malignant. In this article we first present the clinical and imaging features of CRMO to help readers gain an understanding of the disease process, then discuss our imaging approach to CRMO and review other disease processes that sometimes share similar imaging findings to CRMO and review differentiating features to help avoid misdiagnoses.

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.

A systematic approach in the diagnosis of paediatric skull lesions: what radiologists need to know

Paediatric skull lesions are commonly identified on imaging. They can be challenging to image, given their location and size, and often require several imaging modalities to narrow down the differential diagnosis. Accurate diagnosis of these lesions is paramount because the clinical therapy can vary tremendously. In this review, we provide a simple and systematic approach to clinical-radiological features of primary skull lesions. We highlight the imaging characteristics and differentiate pathologies based on imaging appearances. We also accentuate the role of cross-sectional imaging in lesion identification and management implications.

Comparison of whole-body MRI, bone scan, and radiographic skeletal survey for lesion detection and risk stratification of Langerhans Cell Histiocytosis

Accurate risk stratification according to the extent of Langerhans cell histiocytosis (LCH) determined on whole-body evaluation is important for determining the treatment plans and prognosis in patients with LCH. This study aimed to compare the lesion detectability and the accuracy of risk stratification of skeletal survey, bone scan, and whole-body magnetic resonance imaging (WB-MRI) in patients with LCH. Patients with newly-diagnosed LCH who underwent all three imaging modalities were retrospectively included (n = 46). The sensitivity and mean number of false-positives per patient for LCH lesions, and the accuracy of risk stratification of each modality were assessed. WB-MRI had significantly higher sensitivity (99.0%; 95% confidence interval, 93.2–99.9%) than skeletal survey (56.6%; p < 0.0001) and bone scan (38.4%; p < 0.0001) for LCH lesions, and there were no significant differences in the number of false-positives per patient (p > 0.017). WB-MRI tended to have higher accuracy for the risk stratification than skeletal survey and bone scan (concordance rate of 0.98, 0.91, and 0.83, respectively), although the differences were not significant (overall p-value 0.066). In conclusion, WB-MRI had higher detectability for LCH lesions than skeletal survey and bone scan, while the three whole-body imaging modalities had comparable accuracy in the initial risk stratification of LCH.

Imaging of Histiocytosis in the Era of Genomic Medicine

Histiocytosis describes a group of diseases that have long been considered enigmatic in the history of medicine. Recently, novel genomic analyses have identified somatic oncogenic driver mutations responsible for the pathogenesis of these entities. These discoveries have led to the recharacterization of histiocytoses as neoplastic diseases and have opened a new era of precision medicine approaches for treatment. The histiocytic disorders demonstrate a variety of imaging manifestations involving multiple organ systems, and radiologists play a major role in diagnosis and monitoring. An up-to-date knowledge of the novel genomic discoveries and their implications is essential for radiologists to understand the new approaches to treating histiocytic disorders and to contribute as key members of the multidisciplinary treatment team. This article provides a cutting-edge review of the novel concepts in histiocytosis, with a focus on recent genomic discoveries and precision medicine approaches to treating the disease, and describes imaging manifestations with correlative histologic and genomic findings, with an emphasis on adult-onset cases and uncommon subtypes. ^©RSNA, 2018.

Spectrum of abdominal imaging findings in histiocytic disorders

OBJECTIVES

The present article provides an overview of the spectrum of abdominal findings of histiocytic disorders that may be observed in multimodality imaging illustrated by clinical cases from our Imaging Center.

METHODS

We will review abdominal findings of Langerhans cell histiocytosis, Rosai-Dorfman disease, Erdheim-Chester disease, and hemophagocytic syndrome illustrated by clinical cases from our imaging department with histologic correlation.

RESULTS

Abdominal involvement of histiocytic disorders is rare and may occur in the liver, biliary tract, kidney, retroperitoneum, kidney, gastrointestinal tract, and lymph nodes.

CONCLUSION

Histiocytic disorders encompass a group of rare diseases with a wide range of manifestations in which the abdominal involvement is quite infrequent. The role of the radiologist is to report the major imaging findings and the differential diagnosis; however, the imaging features are unspecific and biopsy usually is necessary to establish the definitive diagnosis.

Extrathoracic investigation in adult patients with isolated pulmonary langerhans cell histiocytosis

BACKGROUND

An important objective on diagnosis of patients with Langerhans cell histiocytosis (LCH) is to determine the extent of disease. However, whether systematic extrathoracic investigation is needed in adult patients with clinically isolated pulmonary LCH (PLCH) has not been evaluated.

METHODS

In this prospective, multicentre study, 54 consecutive patients with newly diagnosed clinically isolated PLCH were systematically evaluated at inclusion by bone imaging and blood laboratory testing to search for subclinical extrapulmonary LCH involvement. The patients were followed over a 2-year period. At each visit, they were asked about the presence of extrapulmonary manifestations of LCH.

RESULTS

In the absence of bone symptoms, the skeletal X-ray survey results were normal for all but two patients who had a localised bone lesion consistent with possible LCH involvement, that remained unchanged over 2 years of follow-up. Whole-body bone scintigraphy did not add information to the plain radiography findings for the detection of asymptomatic bone involvement in isolated PLCH. Conversely, it showed nonspecific focal bone uptake in 18% of the patients, mainly corresponding to post-traumatic or degenerative abnormalities unrelated to LCH. Mild leucocytosis due to neutrophilia was observed in 22% of the patients and was not related to their smoking habits. Three patients had mild isolated lymphocytosis without haematological disease, whereas two patients had mild lymphopaenia. A mild inflammatory biological syndrome was observed in a minority of patients without infection or constitutional symptoms and was not associated with progressive disease. A substantial proportion (24.5%) of the patients had abnormal biological liver test results, including elevated liver enzymes and/or cholestasis, which were not linked to LCH involvement in this cohort.

CONCLUSIONS

Obtaining a thorough history and performing comprehensive physical examination are essential for staging patients diagnosed with PLCH. In the absence of symptoms or signs suggestive of extrapulmonary LCH involvement, the systematic performing of recommended bone imaging does not appear informative. Although the observed blood laboratory abnormalities were not specifically related to LCH, performing these tests in the diagnostic workup for PLCH is useful because some of these alterations may impact patient management.

TRIAL REGISTRATION

ClinicalTrials.gov: No. NCT01225601; URL: www.clinicaltrials.gov.

More than just Langerhans cell histiocytosis: a radiologic review of histiocytic disorders

Although Langerhans cell histiocytosis (LCH) is a familiar entity to most radiologists and to pediatric radiologists in particular, it is but one of a group of disorders caused by the overproduction of histiocytes, a subtype of white blood cells. Other less familiar diseases in this category are Erdheim-Chester disease (ECD), juvenile xanthogranuloma (JXG), Rosai-Dorfman disease (RDD), and hemophagocytic lymphohistiocytosis (HLH). This review describes the classification system, clinical manifestations, and pathophysiology of each disease, with particular attention to differential radiographic findings, including typical locations of involvement and varying appearances at radiography, computed tomography, magnetic resonance imaging, ultrasonography, and nuclear medicine imaging. Although LCH has a wide variety of manifestations and appearances, classic imaging findings include vertebra plana, skull lesions with a beveled edge, the "floating tooth" sign, bizarre lung cysts, and an absent posterior pituitary bright spot with infundibular thickening. The classic imaging findings of ECD are a perirenal rind of soft tissue and patchy long bone osteosclerosis. RDD has more nonspecific imaging findings, including lymphadenopathy (most commonly cervical) and intracranial lesions. Imaging findings in HLH are broad, with the most common abnormalities being hepatosplenomegaly, cerebral volume loss, and periventricular white matter abnormalities. JXG can manifest at imaging, but radiology does not play a major role in diagnosis. Familiarity with these disorders and their associated imaging findings facilitates correct and timely diagnosis. Imaging also features prominently in the assessment of treatment response.

Clinical outcomes of radiation therapy in the management of Langerhans cell histiocytosis

OBJECTIVES

Langerhans cell histiocytosis (LCH) is a rare disease with variable clinical presentation. In the present study, we report on the effectiveness and clinical complications of radiation therapy in children with LCH.

MATERIALS AND METHODS

We retrospectively reviewed all patients with LCH treated with radiation therapy over a 6-decade period at a single institution. Radiotherapy data, clinical features, radiographic data, and vital status were analyzed.

RESULTS

The mean age at diagnosis for 69 patients was 5.3 years (3 mo to 37 y) and the median duration of follow-up was 6 years (7 d to 32 y). Radiation therapy was performed for 169 sites, primarily bone lesions. The median radiotherapy dose was 10 Gy (2.5 to 45 Gy). Radiographic follow-up data were available for 139 of the sites treated and clinical follow-up was available for 156 of sites treated. The radiographic local control was 91.4%, and 13% of lesions showed complete sclerosis or reconstitution of bone. A total of 90.4% of patients reported stabilization or improvement in lesion-related symptoms, most often pain. Twelve patients had diabetes insipidus at diagnosis or during follow-up. Eight of these patients received radiation treatment to the pituitary and none experienced a reduction in desmopressin dosage posttreatment. Radiation complications were few, including femoral neck fracture in 1 patient and facial asymmetry in 3 patients. No secondary malignancies were observed.

CONCLUSIONS

Radiotherapy for LCH has high rates of local control and symptomatic improvement. Importantly, however, there is evidence of short-term and long-term morbidity when children are treated with low-dose irradiation.

A Rare and Unusual Case of Burkitt's Lymphoma Presenting with a Prostate Mass in a 12-Year-Old Boy

Burkitt's lymphoma is the most frequent subtype of non-Hodgkin's lymphoma in childhood. Radiographic findings are protean and can often overlap with other neoplastic and nonneoplastic processes. We present an unusual case of Burkitt's lymphoma in a 12-year-old boy presenting with a one-week history of urinary retention, dysuria, and “tailbone pain,” as well as a 4-week history of jaw pain, initially treated as a dental abscess. On dental radiography, the patient was found to have resorption of alveolar bone adjacent to the lower first molars bilaterally, in keeping with “floating teeth,” classically associated with Langerhans cell histiocytosis. Additionally, a large, eccentric, prostatic mass was noted, prompting the inclusion of rhabdomyosarcoma on the differential diagnosis, with subsequent definitive diagnosis of Burkitt's lymphoma on tissue and bone marrow biopsy. This case highlights the imaging overlap of these childhood neoplasms with an unusual lymphomatous prostate mass. It is important that the radiologists and pediatricians be aware of this potential overlap and the unusual presentation of Burkitt's lymphoma.

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 of spine: a comparative study of clinical, imaging features, and diagnosis in children, adolescents, and adults

BACKGROUND CONTEXT

Langerhans cell histiocytosis (LCH) of the spine has been well documented in the literature, but most studies concern management of the disease. No focused report on the differences in clinical and radiographic features of spinal LCH among children, adolescents, and adults exists.

PURPOSE

To review and stress the clinical and imaging differences of spinal LCH in children, adolescents, and adults to avoid false diagnosis.

STUDY DESIGN

A retrospective study of children and adults with LCH of the spine.

PATIENT SAMPLE

Consecutive patients treated at our institution.

OUTCOME MEASURES

Visual analog scale for pain, Frankel scale for neurologic status, and X-ray, computed tomography (CT) and magnetic resonance imaging (MRI) for imaging.

METHODS

Seventy-six patients with pathology-proven LCH involving the spine were treated at our institution between 1996 and 2010. Only patients with spine involvement pathologically and/or radiographically were included. Two groups were identified based on the age. Group I comprised children and adolescents (age <18 years; n=40) and Group II comprised adults (age ≥18 years; n=36). Analysis included age and gender distribution, clinical presentation, and imaging features and diagnosis. Pathologic diagnosis was performed by needle or open biopsy of the lesions.

RESULTS

Of the 76 patients, 55 were male and 21 were female (ratio of 2.62:1). Neck or back pain was the most common symptom in all patients and was the only presenting symptom in some patients. Restricted motion of spine was the most frequent symptom secondary to pain. Thirty-seven patients presented with neurologic symptoms. Adult patients were more likely to suffer neurologic deficits (p<.005). The distribution of lesions revealed predominance in the cervical spine, followed by thoracic and lumbosacral spine. Plain radiology of children and adolescents with spinal LCH usually revealed a typical vertebral plana, but the adult patients represented different severity of vertebral collapse without typical features. The images of CT scans between the two groups were similar, and all revealed lytic lesions in vertebral bodies and/or posterior elements. In Group I, lesions showed hypointense on T1-weighted images in 15 cases and isointense in 25 cases. Nineteen patients presented as intermediate to slight high signal on T2-weighted images, and the remaining patients presented as hyperintense on T2-weighted images. In Group II, lesions showed hypointense on T1-weighted images in 29 cases, isointense on T1-weighted images in seven cases, and hyperintense on T2-weighted images in 36 cases. Paraspinal soft tissue mass was detected in 28 and 23 cases in Group I and Group II, respectively. Fifteen children and adolescent patients versus 23 adult patients had epidural spinal cord compression. Oversleeve-like or dumbbell sign was observed in 21 cases in Group I but only in four cases in Group II.

CONCLUSIONS

The most common clinical manifestations of LCH of the spine were neck or back pain, followed by restricted motion of spine, neurologic symptoms, and deformity. Neurologic deficits were more frequent in adult patients. Vertebral plana is the typical imaging feature in children and adolescent patients but seldom in adults. Computed tomography is best for characterizing anatomy of the involved vertebra, and MRI is best for delineating marrow and soft tissue. The oversleeve-like sign on MRI may be a feature of spinal LCH as well as vertebra plana in children and adolescents. Needle biopsy under CT guidance should be performed before a treatment strategy is determined.

Multisystemic Langerhans cell histiocytosis with advanced lung involvement

Langerhans cell histiocytosis is a rare disease of unknown cause, characterized by the proliferation of histiocytic cells (Langerhans cells), that can sometimes be especially difficult to diagnose due to its wide clinical spectrum, ranging from a single lesion to a multisystemic disorder. Appropriate disease staging is fundamental, since treatment depends upon the severity of the disease, and imaging methods play a fundamental role not only in diagnosing and assessing the extent of Langerhans cell histiocytosis, as well as guiding the appropriate treatment for the patient and their monitoring.

Langerhans cell histiocytosis of bone in children: a long-term retrospective study

Langerhans cell histiocytosis is rare and frequently involves the bone. We retrospectively reviewed the orthopaedic aspects (symptoms, localizations, treatments) and the long-term outcome [disease status, overall survival (OS), event-free survival (EFS)] of 121 patients (June 1968-December 2009). The main symptom was local pain. The orthopaedic treatment was mainly conservative. The most frequent localization was osseous monofocal (62% of monosystemic diseases). Monosystemic and osseous monofocal localizations, treatment after 1991 (OS, P=0.007; EFS, P=0.03) and age older than 2 years (OS, P=0.003; EFS, P=0.001) were prognostic factors that were positively associated with survival. Oncologic treatment has improved over time, translating into better survival. A biopsy is often mandatory.

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.

Rare case of unifocal Langerhans cell histiocytosis in four-month-old child

Langerhans cell histiocytosis (LCH) comprises a group of disorders, the common feature of which is Langerhans cell proliferation. The clinical presentation is highly varied. The severity and prognosis of the disease are dependent on the type and extent of organ involvement. This paper reports a rare case of a four-month-old white male with unifocal LCH limited exclusively to the mandible, discussing the diagnosis, radiographic and immunohistochemical aspects, treatment and monitoring multidisciplinary of the case.

Primary musculoskeletal Langerhans cell histiocytosis in children: an analysis for a 3-decade period

BACKGROUND

Langerhans cell histiocytosis (LCH) is a rare group of disorders of unknown etiology with a wide spectrum of clinical presentation. We sought to identify what, if any, has changed in the past 3 decades. This review outlines the current concepts in etiology and molecular biology, clinical manifestations, imaging features, treatment guidelines, and outcomes for skeletal LCH.

METHODS

A database of LCH cases diagnosed at a tertiary referral center during a 3-decade period was retrospectively reviewed to identify children with primary bone involvement. All patients' charts and available imaging examinations were reviewed, and the data collected included sex, age, number and location of the musculoskeletal lesions, presence of extraskeletal lesions and/or systemic disease, presence of clinical symptoms, treatment (medical and/or surgical), complications, and outcomes.

RESULTS

Seventy-nine children met the inclusion criteria. Forty-five (57%) of the 79 children had single-bone disease, with a mean age at presentation of 8.9 years, whereas 34 (43%) of the 79 children presented with multiple skeletal lesions (range, 2-7 lesions) at a mean age of 7.4 years. There were 165 skeletal lesions in the 79 patients (mean, 2 lesions per patient). The most common presenting symptom was pain at the lesion site (63 patients, 79%). On imaging, the lesion usually presented as a well-defined, radiolucent lesion located within the diaphysis or metaphysis. Among children with single-bone involvement, 11 underwent observation and symptomatic treatment, 17 had biopsy followed by observation and symptomatic treatment, and 17 had biopsy followed by excision. Eight children also received chemotherapy, and 2 had radiation (early in the series). Among children with multiple-bone disease, 10 underwent biopsy followed by symptomatic treatment, 24 underwent biopsy, followed by chemotherapy, and 3 also received radiation (early in the series).

CONCLUSION

There is variability of presentation in musculoskeletal LCH. Biopsy is usually indicated for diagnostic confirmation. Although the natural history for most lesions is of gradual healing, curettage and grafting are sometimes indicated to accelerate the healing process. Internal fixation for stability is occasionally necessary. Chemotherapy is used for multisystemic disease, and radiotherapy is no longer used.

Imaging of painful scoliosis

Scoliosis is defined as a lateral deviation of the spine from the normal plumb line. Commonly, there is a rotational component and deviation also in the sagittal plane (kyphosis or hyperlordosis). When scoliosis presents in adults, it is often painful. In contrast, back pain in a child is considered rare, and serious underlying pathology should be excluded, particularly since idiopathic scoliosis is typically painless. A painful scoliosis in a child or adolescent, especially if the patient has a left-sided curve, should be examined thoroughly. The aim of this review is to illustrate the causes of a painful scoliosis in children, adolescents and adults.

Successful outcome of Langerhans cell histiocytosis complicated by therapy-related myelodysplasia and acute myeloid leukemia: a case report

BACKGROUND

Various therapeutic options are available for the management of Langerhans cell histiocytosis. However, treatment administered to control this disease may be complicated by acute leukemia.

CASE PRESENTATION

A 34 years old male was diagnosed to have Langerhans cell histiocytosis in March 1999. Unfortunately, the cytotoxic chemotherapy and radiotherapy given to control the repeated relapses and exacerbations of the primary disease predisposed him to therapy-induced myelodysplastic syndrome which transformed into acute myeloid leukemia. After achieving complete remission of his leukemia, the patient received an allogeneic hematopoietic stem cell transplant. The allograft was complicated by chronic graft versus host disease that was controlled by various immunosuppressive agents and extracorporal photophoresis.

CONCLUSION

Management of complicated cases of histiocytosis requires various therapeutic modalities and a multidisciplinary approach. Having complications of therapy eg myelodysplasia or acute leukemia make the outcome more dismal and the management options limited to aggressive forms of treatment. High dose chemotherapy followed by an allograft may be a curative option not only for therapy-related myelodysplasia/acute leukemia, but also for frequently relapsing and poorly controlled Langerhans cell histiocytosis.

IL-1 beta and PGE2 levels are increased in the saliva of children with Langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH) is a rare disorder mainly of children, whose pathogenesis is still unknown. Some studies have demonstrated that LCH lesions produce different cytokines abnormally that may be relevant to the pathogenesis of the disease. The purpose of this study was to investigate interleukin-1 beta (IL-1 beta) and prostaglandin E2 (PGE(2)) levels in saliva from children with different clinical subtypes of LCH. We studied 29 children with LCH: seven unifocal (Group I), seven multifocal (Group II), 15 multisystemic (Group III) and 12 healthy volunteers (Group IV). Salivary IL-1 beta and PGE(2) levels were significantly higher in LCH than in normal children. A multi-comparison test showed significantly (P < 0.001) higher levels of both IL-1 beta and PGE(2) in saliva from Group III compared with Groups II and I. A significant correlation (r = 0.05) between IL-1 beta and PGE(2) concentrations in saliva from each group was determined. Our findings demonstrated an association between high concentrations of salivary IL-1 beta and PGE(2) and advanced stages of the disease. This allows us to suggest that the abnormal amount of these factors in saliva may serve as a risk marker for disease progression.

Extraosseous langerhans cell histiocytosis in children

Langerhans cell histiocytosis, a rare disease that occurs mainly in children, may produce a broad range of manifestations, from a single osseous lesion to multiple lesions involving more than one organ or system. The clinical course varies widely in relation to the patient's age. Multisystem disease may demonstrate especially aggressive behavior in very young children, with the outcome depending largely on the stage of disease and the degree of related organ dysfunction at the time of diagnosis. Extraosseous manifestations are less commonly seen than osseous ones and may be more difficult to identify. To accurately detect extraosseous Langerhans cell histiocytosis at an early stage, radiologists must recognize the significance of individual clinical and laboratory findings as well as the relevance of imaging features for the differential diagnosis. The pattern and severity of pulmonary, thymic, hepatobiliary, splenic, gastrointestinal, neurologic, mucocutaneous, soft-tissue (head and neck), and salivary involvement in Langerhans cell histiocytosis generally are well depicted with conventional radiography, ultrasonography, computed tomography, and magnetic resonance imaging. However, the imaging features are not pathognomonic, and a biopsy usually is necessary to establish a definitive diagnosis.

Lacrimal gland and perioptic nerve lesions due to Langerhans cell histiocytosis (2007: 9b)

We report a patient presenting with bilateral lacrimal gland involvement and perioptic nerve sheath lesions due to Langerhans cell histiocytosis (LCH) invasion. LCH is a rare multisystemic disease characterized by a clonal proliferation of Langerhans cells. All organs may be involved with a clinical spectrum ranging from a solitary bone lesion to a severe life-threatening multisystem disease. Osteolytic orbital bone lesions with extension into the adjacent orbital soft tissues have been described. To our knowledge, lacrimal gland involvement has probably been described only once before. Perioptic nerve lesions are also very rare, having been described only three times before.

Imaging of Back Pain in Children and Adolescents

PURPOSE

To present the imaging findings of the wide spectrum of musculoskeletal diseases causing back pain in children and adolescents.

DISCUSSION

Back pain in children is a rare condition but may denote a serious health problem; hence, full clinical history, physical examination, and appropriate laboratory studies should be obtained. In this scientific exhibit, we present the imaging findings of the variable musculoskeletal diseases that are associated with back pain in children and adolescents. These disease processes include scoliosis of various causes; spondylolysis; spondylolisthesis; traumatic injuries; disc degeneration and herniation; Scheuermann's disease; spondylodiscitis; tumors (primary, secondary, hematogenous); and miscellaneous conditions (eg, metabolic disorders, sickle cell disease, osteoporosis).

CONCLUSION

A wide spectrum of diseases causing back pain in children is presented. Radiologists should be aware of the imaging findings of this rather uncommon entity to help in reaching the appropriate diagnosis.

Whole-body MRI of Langerhans cell histiocytosis: comparison with radiography and bone scintigraphy

BACKGROUND

In Langerhans cell histiocytosis (LCH) evaluation of the extent of disease is one of the major predictors of patient outcome. Historically this is undertaken using plain radiography and bone scintigraphy. Recently, whole-body (WB) MRI has been reported to be useful in detecting skeletal and extraskeletal metastases in both adults and children.

OBJECTIVE

To evaluate the usefulness of WB MRI in patients with LCH in comparison with plain radiography and bone scintigraphy.

MATERIALS AND METHODS

In nine children (1-7 years of age; mean 3.3 years) who had a pathological diagnosis of LCH and had either plain radiography or bone scintigraphy for comparison, 43 WB MR examinations were performed. Skeletal and extraskeletal lesions of the disease on WB MRI were compared with those on plain radiography and bone scintigraphy.

RESULTS

LCH showed unifocal single-system involvement in one patient, multifocal single-system involvement in three, and multifocal multisystem disease in five. WB MRI identified additional skeletal lesions in three (38%) of eight patients, compared with plain radiography, and in two (25%) of eight, compared with bone scintigraphy. WB MRI detected extraskeletal lesions of the disease in five (56%) of the nine patients exclusively, except for one patient whose lung lesions were also detected on plain radiography. In two patients, treatment was changed according to WB MRI findings.

CONCLUSION

WB MRI is a useful initial and follow-up diagnostic method to assess the extent of LCH because WB MRI not only identifies more skeletal lesions of the disease than do plain radiography and bone scintigraphy, but also detects extraskeletal lesions of the disease.

Langerhans cell histiocytosis and human herpes virus 6 (HHV-6), an analysis by real-time polymerase chain reaction

Patients with Langerhans cell histiocytosis (LCH) usually present to orthopedic surgeons because this disease most commonly affects bone. The pathogenesis of LCH is unknown, although roles for environmental, infectious, immunologic, and genetic causes have been postulated. More specifically, there is limited data suggesting that human herpes virus 6 (HHV-6) may be a potential etiologic agent. Frozen biopsy material was obtained from 13 patients with LCH and 20 patients without the disease. After ensuring histologic adequacy of the material, the tissue was tested for HHV-6 by qualitative and quantitative real-time TaqMan PCR. Four of 13 patients with LCH had evidence of HHV-6 DNA in their tissue while 7 of 20 control patients tested positive for HHV-6 genome. Viral loads are reported for the positive patients; no statistical difference was observed in the presence or quantity of HHV-6 DNA found in either population, suggesting that the prevalence of HHV-6 in the tissue of LCH patients is the same as that found in tissue from individuals without disease.

Langerhans' cell histiocytosis: pathology, imaging and treatment of skeletal involvement

Langerhans' cell histiocytosis (LCH) is manifested in a variety of ways, the most common being the eosinophilic granuloma, a localized, often solitary bone lesion that occurs predominantly in the pediatric age group. The hallmark of LCH is the proliferation and accumulation of a specific histiocyte: the Langerhans' cell. In bone this may cause pain and adjacent soft-tissue swelling, but some lesions are asymptomatic. LCH can involve any bone, but most lesions occur in the skull (especially the calvarium and temporal bones), the pelvis, spine, mandible, ribs, and tubular bones. Imaging diagnosis of the disease in bone is first based on the plain radiographic appearance, which is usually a central destructive, aggressive-looking lesion. In the skull, the lesions develop in the diploic space, are lytic, and their edges may be beveled, scalloped or confluent (geographic), or show a "button sequestrum." Vertebral body involvement usually causes collapse, resulting in vertebra plana. With significant recent improvements in the quality of gamma cameras, imaging techniques, and in studying children, bone scintigraphy at diagnosis and on follow-up usually reveals the sites of active disease, especially when the involvement is polyostotic. CT and MR imaging are very useful in providing detailed cross-sectional anatomic detail of the involved bone, including the bone marrow and the adjacent soft tissues. CT is better suited for demonstrating bone detail and MR imaging for bone marrow and soft-tissue involvement.

Imaging of low back pain in children and adolescents

In children with low back pain (LBP), a specific cause is often identified. LBP has a relatively high prevalence during school years. However, only a minority of the children suffering from LBP seek medical attention. Protracted back pain in childhood is a serious condition that should be thoroughly investigated. This article is a systematic review of the intrinsic causes of LBP. Imaging modalities are discussed, with emphasis on magnetic resonance imaging. We have divided the intrinsic causes of LBP into four main groups: mechanical, developmental, infectious/inflammatory, and neoplastic. Disk protrusion is prevalent in young athletes. Spondylolysis and spondylolisthesis are the most common causes of chronic LBP in children. Thoracic or thoracolumbar Scheuermann disease causes kyphosis while a lumbar localization is more painful. Childhood diskitis is associated with fever and leukocytosis. Spinal inflammatory arthritides in children include juvenile rheumatoid arthritis, the juvenile spondyloarthropathies, and SAPHO syndrome, where spine as well as sacroiliac joint changes may be seen. Cysts, tumors, tumor-like lesions, and metastases are infrequent causes of back pain in children. Several of these conditions are described and illustrated in this review of LBP in children and adolescents.

Lumps and Bumps on the Head in Children: Use of CT and MR Imaging in Solving the Clinical Diagnostic Dilemma

Lumps and bumps of the scalp are a common presenting complaint in children and often pose a diagnostic dilemma. These lesions can be difficult to image, with evaluation confounded by their small size. However, accuracy in diagnosis is critical because the diagnostic and therapeutic implications can vary significantly. The clinical examination can be helpful in developing the differential diagnosis and the imaging strategy. Often, however, a single imaging study is insufficient, and the radiologist finds it necessary to image with more than one modality to correctly diagnose a lesion and provide adequate information for the surgeon. Radiography and ultrasonography are often the initial screening diagnostic tests, followed by magnetic resonance (MR) imaging or computed tomography (CT) for more detail. Multidetector thin-section CT and thin-section MR imaging with surface coils are beneficial in the work-up of these small lesions of the head and neck. The use of newer MR imaging sequences such as heavily T2-weighted single-shot turbo spin-echo imaging and diffusion-weighted imaging can improve the characterization of difficult lesions. Familiarity with the variety of new imaging tools and techniques that are available can help characterize pediatric head and neck lesions and guide clinical management.

Extra-osseous involvement of Langerhans' cell histiocytosis in children

The predominant clinical and radiological features of Langerhans' cell histiocytosis (LCH) in children are due to osseous involvement. Extra-osseous disease is far less common, occurring in association with bone disease or in isolation; nearly all anatomical sites may be affected and in very various combinations. The following article is based on a multicentre review of 31 children with extra-osseous LCH. The objective is to summarise the diverse possibilities of organ involvement. The radiological manifestations using different imaging modalities are rarely pathognomonic on their own. Nevertheless, familiarity with the imaging findings, especially in children with systemic disease, may be essential for early diagnosis.

[Bone scintigraphy and somatostatin receptor scintigraphy in pediatric patients with bone involvement in Langerhans cell histiocytosis]

Langerhans cell histiocytosis (LCH) is a granulomatous disease which can involve multiples sites of the body. Diagnostic imaging is of utmost importance in the management of these patients. Up to now radiographic skeletal survey and bone scintigraphy (BS) have been used to assess bone involvement (both with low specificity). Magnetic resonance imaging (MRI) and CT have been used to assess visceral involvement but with the limitation that they cannot give information about the functional status. Recently somatostatin receptor scintigraphy (SSRS) has been proposed to detect active lesions and to monitor response to treatment. The aim of this study is to assess bone and somatostatin receptor scintigraphy in the detection of bone involvement in LCH in children. Twenty scintigraphies (12 SSRS and 8 BS) were performed in seven patients (3 girls and 4 boys) aged at diagnosis: 18 month-12 years (mean age 6 years). The findings obtained in the scintigraphies were compared with clinical evolution and other imaging techniques. Bone scintigraphy detected all the LCH bone lesions, and discovered one unknown lesion. SSRS scintigraphy visualised the active lesions in 3 patients (clinical and other imaging techniques were also positive). SSRS was negative in one patient classified as disease free and another in clinical remission. SSRS detected 2 new unknown bone lesions, but could not detect LCH bone lesions confirmed in other imaging techniques in 2 patients. Somatostatin receptor and Bone scintigraphy can be used to detect active LCH bone lesions in children and can help to monitor response to treatment. Further studies with more patients are needed to confirm the diagnostic usefulness of these techniques.

Paediatric manifestations of Langerhans cell histiocytosis: a review of the clinical and radiological findings

Langerhans cell histiocytosis is a rare disease in children. However, its ability to present in many ways, to mimic other conditions, and to manifest itself in many organs makes it a fascinating disease for radiologists. This article reviews the history of the disease, the features that are most useful in determining prognosis, and the various radiological findings seen in paediatric patients.