Extra-osseous involvement of Langerhans' cell histiocytosis in children

Langerhans cell histiocytosis of the thyroid mimicking thyroiditis in a boy: a case report and literature review

BACKGROUND

Langerhans cell histiocytosis affecting the thyroid commonly presents with nonspecific clinical and radiological manifestations. Thyroid Langerhans cell histiocytosis is typically characterized by non-enhancing hypodense lesions with an enlarged thyroid on computed tomography medical images. Thyroid involvement in LCH is uncommon and typically encountered in adults, as is salivary gland involvement. Therefore, we present a unique pediatric case featuring simultaneous salivary and thyroid involvement in LCH.

CASE PRESENTATION

A 3-year-old boy with complaints of an anterior neck mass persisting for 1 to 2 months, accompanied by mild pain, dysphagia, and hoarseness. A physical examination revealed a 2.5 cm firm and tender mass in the left anterior neck. Laboratory examinations revealed normal thyroid function test levels. Ultrasonography revealed multiple heterogeneous hypoechoic nodules with unclear and irregular margins in both lobes of the thyroid. Contrast-enhanced neck computed tomography revealed an enlarged thyroid gland and bilateral submandibular glands with non-enhancing hypointense nodular lesions, and multiple confluent thin-walled small (< 1.5 cm) cysts scattered bilaterally in the lungs. Subsequently, a left thyroid excisional biopsy was performed, leading to a histopathological diagnosis of LCH. Immunohistochemical analysis of the specimen demonstrated diffuse positivity for S-100, CD1a, and Langerin and focal positivity for CD68. The patient received standard therapy with vinblastine and steroid, and showed disease regression during regular follow-up of neck ultrasonography.

CONCLUSIONS

Involvement of the thyroid and submandibular gland as initial diagnosis of Langerhans cell histiocytosis is extremely rare. It is important to investigate the involvement of affected systems. A comprehensive survey and biopsy are required to establish a definitive diagnosis.

Langerhans Cell Histiocytosis With Thyroid Involvement on 18 F-FDG PET/MR

ABSTRACT

An 18-month-old otherwise healthy girl presented with 1 month of neck swelling. Based on ultrasonography that showed diffusely enlarged heterogeneous thyroid gland, a presumed diagnosis of thyroid cancer was made. Subsequent core needle biopsy revealed Langerhans cell histiocytosis extensively involving the thyroid. 18 F-FDG PET/MR was performed for staging and to evaluate the local extent of the disease in the neck. PET/MR demonstrated a hypermetabolic neck mass inseparable from the thyroid gland. The mass encased the major vessels, trachea, and esophagus without compression or invasion. Osseous involvement was excluded by both skeletal survey and PET/MR.

Hepatobiliary and Gastrointestinal Involvement in Langerhans Cell Histiocytosis-Spectrum of Three Cases

Langerhans cell histiocytosis (LCH) is a rare group of disorder, due to clonal neoplastic proliferation of dendritic cells in the bone marrow expressing a Langerhans cell phenotype. 1 This disease particularly affects the pediatric age group and young adults and often presents with skin rashes, lung infiltrates, and bone lesions. It can also manifest with endocrine dysfunction and hematopoietic disorders. Involvement of gastrointestinal tract is very rare. Herein, we present a spectrum of three cases with gastrointestinal involvement.

Rosai-Dorfman disease mimicking images of meningiomas: Two case reports and literature review

Background:

Rosai-Dorfman disease (RDD) is a rare non-Langerhans cell histiocytic proliferative disorder classically as a massive cervical lymphadenopathy. However, over the years, extranodal locations were confirmed with the central nervous system involvement in less than 5% of cases, which is marked as a significant differential diagnosis of meningiomas, with which they are widely confused due to the similarity of their radiological images.

Case Description:

We report a 37-year-old man and 45-year-old man who were diagnosed with intracranial RDD but whose radiological images mimic meningiomas, requiring anatomopathological and tumor’s immunohistochemistry for definitive diagnosis. Moreover, a review of 184 publications with 285 cases of intracranial involvement of this disease was also performed, comparing these findings with those brought in the previous studies.

Conclusion:

Intracranial Rosai-Dorfman tumors should always be remembered as differential diagnosis of meningiomas since they are similar radiologically and macroscopically. Once remembered and diagnosed, the lesion must be treated following the same pattern of resection done in meningiomas and, treatment’s differences will not occur in the surgical excision technique, but in complementary chemotherapy implementation, radiotherapy, and even with radiosurgery aid, depending on the case. Thus, it is possible to obtain better results than with just the isolated surgical procedure.

CT findings of pulmonary cysts

Pulmonary cysts are thin-walled radiolucent lesions that may appear in a variety of uncommon disorders known as diffuse cystic lung diseases (DCLD) that essentially includes lymphangioleiomyomatosis (LAM), Langerhans cell histiocytosis (LCH), lymphocytic interstitial pneumonia (LIP), Pneumocystis jiroveci pneumonia (PJP), and Birt-Hogg-Dubé syndrome (BHDS). Moreover, they have been reported in several cases of coronavirus disease 2019 (COVID-19). The purpose of this review is to provide a practical approach for evaluating lung cysts when encountered on CT. We describe the imaging findings of DLCD emphasising their differences in terms of shape and distribution of the cysts, as well as their association with other findings such as nodules or ground-glass opacities, which may help in making a confident diagnosis. We also discuss the link between pulmonary cysts and COVID-19.

Langerhans Cell Histiocytosis with Uncommon Liver Involvement: A Case Report

Patient: Female, 60-year-old

Final Diagnosis: Langerhans cell histiocytosis

Symptoms: Fatigue • weight loss

Medication: —

Clinical Procedure: —

Specialty: Radiology

Case series of cutaneous Langerhans cell histiocytosis in Indonesian children; The clinicopathological spectrum

Langerhans Cell Histiocytosis (LCH) is a rare disease characterized by the clonal proliferation of Langerhans cells, which are immunoreactive to S-100 and CD-1a/ CD207 (Langerin). Cutaneous involvement is the most common presentation of LCH in children. It is suggested that the patients with single-system LCH limited to the skin have a better prognosis than those with systemic involvement. Three histologic reactions of cutaneous LCH have been reported and are associated with the clinical types of LCH. These histological reactions include: proliferative, granulomatous, and xanthomatous. This study presents the clinicopathological features of ten cutaneous LCH cases collected from Dr. Sardjito General Hospital Yogyakarta Indonesia between 2014-2018. The ten cases showed various clinical features, in which some features mimic other diseases. The microscopic features of skin biopsies showed granulomatous reaction in 80% of cases and proliferative reaction in the other 20%. Five patients (50% of cases) who died had systemic manifestation of thrombocytopenia, anemia, icterus, hepatosplenomegaly, and revealed the granulomatous type from their skin biopsy specimens. The clinical recognition of LCH and subsequent histological reaction determination are important since some cases may develop multisystem disease and have a poor prognosis.

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.

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

RATIONALE

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

PATIENT CONCERNS

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

DIAGNOSES

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

INTERVENTIONS

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

OUTCOMES

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

LESSONS

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

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.

Histiocytic disorders of the chest: imaging findings

Histiocytic disorders of the chest comprise a broad spectrum of diseases. The lungs may be involved in isolation or as part of systemic disease. Some of these disorders are primary and have unknown etiology, and others result from a histiocytic response to a known cause. Among primary histiocytic disorders, pulmonary Langerhans cell histiocytosis (PLCH) is the most common; others include Erdheim-Chester disease and Rosai-Dorfman disease. Adult PLCH occurs almost exclusively in adults aged 20-40 years who smoke. Pediatric PLCH is extremely rare and typically occurs as part of multisystemic disease. Erdheim-Chester disease affects middle-aged and older adults; thoracic involvement usually occurs as part of systemic disease. Rosai-Dorfman disease affects children and young adults and manifests as painless cervical lymphadenopathy. Examples of secondary histiocytic disorders are storage diseases such as Gaucher disease, Niemann-Pick disease, and Fabry disease; pneumoconiosis such as silicosis and coal workers' pneumoconiosis; and infections such as Whipple disease and malakoplakia. These disorders are characterized at histopathologic examination on the basis of infiltration of alveoli or the pulmonary interstitium by histiocytes, which are a group of cells that includes macrophages and dendritic cells. Dendritic cells are a heterogeneous group of nonphagocytic antigen-presenting immune cells. Immunohistochemical markers help to distinguish among various primary histiocytic disorders. Characteristic radiologic findings in the appropriate clinical context may obviate biopsy to establish a correct diagnosis. However, in the absence of these findings, integration of clinical, pathologic, and radiologic features is required to establish a diagnosis.

Persistent pulmonary interstitial emphysema in a case of Langerhans cell histiocytosis

We present the case of a 10-month-old boy with multisystem Langerhans cell histiocytosis showing thin-walled lung cysts along with computed tomography (CT) evidence of persistent pulmonary interstitial emphysema (PPIE), in the absence of pneumothorax or pneumomediastinum. Follow-up CT performed after 6 months demonstrated complete resolution of interstitial emphysema.

Hepatic involvement of Langerhans cell histiocytosis in children--imaging findings of computed tomography, magnetic resonance imaging and magnetic resonance cholangiopancreatography

BACKGROUND

Langerhans cell histiocytosis is a rare disease that occurs mainly in children, and hepatic involvement is generally a poor prognostic factor.

OBJECTIVE

To describe CT and MRI findings of hepatic involvement of Langerhans cell histiocytosis in children, especially the abnormal bile duct manifestation on magnetic resonance cholangiopancreatography (MRCP).

MATERIALS AND METHODS

Thirteen children (seven boys, six girls; mean age 28.9 months) were diagnosed with disseminated Langerhans cell histiocytosis. They underwent CT (n = 5) or MRI (n = 4), or CT and MRI examinations (n = 4) to evaluate the liver involvement.

RESULTS

Periportal abnormalities presented as band-like or nodular lesions on CT and MRI in all 13 children. The hepatic parenchymal lesions were found in the peripheral regions of the liver in seven children, including multiple nodules on MRI (n = 6), and cystic-like lesions on CT and MRI (n = 3). In 11 of the 13 children the dilatations of the bile ducts were observed on CT and MRI. Eight of the 13 children underwent MR cholangiopancreatography, which demonstrated stenoses or segmental stenoses with slight dilatation of the central bile ducts, including the common hepatic duct and its first-order branches. The peripheral bile ducts in these children showed segmental dilatations and stenoses.

CONCLUSION

Stenosis of the central bile ducts revealed by MR cholangiopancreatography was the most significant finding of liver involvement in Langerhans cell histiocytosis in children.

Rosai-Dorfman disease of the central nervous system: report of 6 cases and review of the literature

Rosai-Dorfman disease (RDD), also known as sinus histiocytosis with massive lymphadenopathy (SHML), is an uncommon benign idiopathic lymphoproliferative disorder. The histologic hallmark of RDD is the finding of emperipolesis displayed by lesional histiocytes. While RDD most commonly affects lymph nodes, extranodal involvement of multiple organs has been reported, including the central nervous system (CNS). However, CNS involvement in RDD is rare and is not well characterized. As a result, therapeutic approaches to CNS involvement in RDD are not well established. Herein we report 6 cases of RDD with isolated CNS involvement and review the literature on RDD with CNS involvement. One of the presented cases exhibited intramedullary involvement of the spinal cord--a very rare form of RDD with CNS involvement.

Clinical profile of Langerhans Cell Histiocytosis at a tertiary centre: a prospective study

OBJECTIVE

To study the varied presentations of Langerhans Cell Histiocytosis (LCH), the differential diagnosis of the varied presentations and the time lag in achieving the diagnosis. Prospective analysis of children diagnosed to have LCH over a period of 51 mo was done. A complete history and physical examination was undertaken in all patients, followed by relevant laboratory and radiological evaluation. Biopsy of the appropriate specimen was done. The extent of the disease was documented, accordingly treated and followed up.

RESULTS

There were 16 children with LCH from October 2005 through December 2009. The age ranged from 8 mo to 72 mo. Diagnosis was confirmed by CD1a/S 100 in 15 children (93.75%). The mean time to arrive at the diagnosis was 9.9 mo. Multisystem disease was documented in 11 (68.75%) children and there were 4 (25.0%) cases of pulmonary LCH. The mean time of follow-up was 14.4 mo (range, 1 mo to 50.6 mo). Most common referral diagnoses in LCH patients was recurrent pneumonia and immunodeficiency.

CONCLUSIONS

There is a need for high index of suspicion for diagnosis of LCH; misdiagnosis is frequent. Pulmonary involvement in children with LCH appears common. It is possibly still underdiagnosed. Nail changes are uncommon, but may act as a marker for multisystem disease. In addition to survival data and analysis of prognostic factors, the prospective collection of data on diverse presentations is essential, along with a high index of suspicion for the diagnosis of LCH.

Multisystem Langerhans cell histiocytosis with liver dysfunction as the first presentation: A case report

Langerhans cell histiocytosis (LCH) is a rare disease of unknown etiology characterized by oligoclonal proliferation of Langerhans cells. The diagnosis of LCH is complicated by the fact that it may involve multiple organ systems and its clinical presentation and course varies, ranging from an isolated to a multisystem disease. We report a 35-year-old male with LCH involving multiple systems, including the bones, lungs, spleen, liver and bile ducts, whose first clinical presentation was liver dysfunction. The patient was diagnosed following a skull biopsy that revealed infiltration of Langerhans cells. However, a liver biopsy revealed sclerosing cholangitis (SC) with no signs of Langerhans cell infiltration, and the clinical manifestations of the involved organs were atypical, leading to a delayed diagnosis. The patient was in partial remission following chemotherapy. In conclusion, findings of this case may aid our understanding of the pathophysiology of LCH and in improving its diagnosis and treatment.

Langerhan's cell histiocytosis: A single institutional experience

Background:

Langerhans cell histiocytosis (LCH) is a disease that primarily affects bone but can be associated with a clinical spectrum that ranges from a solitary bone lesion with a favorable natural history to a multisystem, life-threatening disease process.

Aim:

We analyzed our single institutional experience of managing children with LCH.

Settings and Design:

A total of 40 children of LCH, managed in tertiary cancer center in South India in the period from 2001 to 2005, were evaluated retrospectively.

Materials and Methods:

Clinicopathological features, laboratory findings, treatment modalities and long-term outcome were analyzed.

Results:

Children were aged between 2 months and 12 years, with a mean of 3 years. Majority of the children were below 5 years of age. Group B constituted a bulk of children. Disseminated cases were less (five patients). Liver function dysfunction was seen in four (10%) children. Pulmonary interstitial infiltrates were seen in two (5%) cases. Diabetes insipidus manifested in three patients. There was one death.

Conclusion:

A better understanding of the etiology and pathogenesis of LCH will result in more directed and efficacious treatment regimens.

Digestive system manifestations, diagnosis and treatment of Langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH) is a rare disease characterized by an abnormal proliferation of histiocytes, known as Langerhans cells (LCs). At present, the pathogenesis of LCH remains unknown. LCH often involves the bone, skin, lung, bone marrow and lymph nodes. Besides, the liver, bile duct and gastrointestinal tract may also be affected. LCH has no specific clinical manifestations compared to other digestive system diseases. Once digestive system involvement is diagnosed in LCH patients, prompt treatment (even liver transplantation) should be given. In this paper, we will review the digestive system manifestations, diagnosis and treatment of LCH.

Imaging Features of Thyroid Involvement by Langerhans Cell Histiocytosis

A 2-year-old male presented with fever, rash, right upper quadrant pain, and hyperbilirubinemia and was diagnosed with Langerhans cell histiocytosis (LCH). Periportal, hepatic, pulmonary, thymic, and thyroid involvement was noted on initial imaging. Thyroid gland involvement by LCH is rare. This case illustrates computed tomography, ultrasonography, and magnetic resonance imaging features of LCH of the thyroid.

Imaging lesions of the cavernous sinus

Our aim was to review the imaging findings of relatively common lesions involving the cavernous sinus (CS), such as neoplastic, inflammatory, and vascular ones. The most common are neurogenic tumors and cavernoma. Tumors of the nasopharynx, skull base, and sphenoid sinus may extend to the CS as can perineural and hematogenous metastases. Inflammatory, infective, and granulomatous lesions show linear or nodular enhancement of the meninges of the CS but often have nonspecific MR imaging features. In many of these cases, involvement elsewhere suggests the diagnosis. MR imaging is sensitive for detecting vascular lesions such as carotid cavernous fistulas, aneurysms, and thromboses.

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.

Langerhans cell histiocytosis of mediastinal node

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. In the present study, LCH was presumptively diagnosed on Ultrasound guided Fine needle aspiration cytology (FNAC) of the mediastinal lymph node in a 18 month-old child. The diagnosis was confirmed by histological examination of the biopsy material.S-100 protein localization in the LCH cells is often positive on immunohistochemistry.

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.

Liver involvement in Langerhans cell histiocytosis

Liver involvement in Langerhans cell histiocytosis (LCH) typically presents with hepatomegaly and other signs of liver dysfunction. We present an 11-month-old child having only minimally elevated liver enzymes as an indication of liver involvement. Using sonography as the initial diagnostic tool followed by MRI, LCH of the liver was revealed. A review of sonographic, CT, MRI and MR cholangiopancreatography findings in liver LCH is presented. We recommend that physicians consider sonography and MRI screening for liver involvement in patients with newly diagnosed LCH, as periportal involvement may be present with little or no liver function abnormality present, as in this patient.

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.