Langerhans cell histiocytosis with the radiographic findings of Erdheim-Chester disease

The triptych of mixed histiocytosis: a systematic review of 105 cases and proposed clinical classification

Histiocytoses are one of the ultimate diagnostic challenges that every physician face at least once in his/her life. Giving their protean manifestation and differentiated therapeutic needs, histiocytosis requires extensive characterization and multidisciplinary management. Mixed histiocytosis is an emerging group of syndromes defined by the overlap of Langerhans cell histiocytosis and another histiocytic disorder of different type. Despite rare, it may account for up to a fifth of systemic histiocytosis patients in some series. In this work, we comprehensively review for the first time the clinical, radiological, histopathological and molecular features of mixed histiocytosis in children and adults. Moreover, we propose a clinical classification in three groups that differentiate patients with systemic involvement and worse overall survival to other groups with more localized manifestations and indolent behavior, wanting to ease their recognition and treatment. Interestingly we also found that mixed histiocytosis harbor BRAFV600E mutations with a higher frequency comparing to all other histiocytoses, and may therefore benefit of specific inhibitory drugs.

18F-FDG PET/CT in Erdheim-Chester Disease: Imaging Findings and Potential BRAF Mutation Biomarker

The purpose of this study was to evaluate ¹⁸F-FDG PET/CT for the diagnosis, management, and treatment of Erdheim-Chester disease (ECD). Methods: Our institutional database (2007-2017) was retrospectively reviewed for patients with pathologically proven ECD. A chart review yielded demographics, clinical information, and 5 categories of clinical impact. Two radiologists in consensus interpreted the images. Imaging findings were correlated with clinical data. Results: Seventy-one ¹⁸F-FDG PET/CT examinations were performed for 32 patients. The average SUV_max of the most active disease site was 9.2 (SD, 6.1). The most common sites involved were the skeleton (90.6% of patients, including 47% with axial and pelvic skeletal involvement), kidneys (81.3%), and central nervous system (CNS) (46.9%). Twenty-six patients were tested for a proto-oncogene B-Raf ^V600E (BRAF) mutation (18 had the mutation and 8 did not). The presence of a BRAF mutation was associated with ¹⁸F-FDG-avid CNS disease (P = 0.0357), higher SUV_max (P = 0.0044), and greater mortality (P = 0.0215). The presence of CNS disease had 88% specificity and a 92% positive predictive value for predicting the presence of a BRAF mutation. PET/CT examination results influenced patient management in 48% of cases (34/71). Conclusion:¹⁸F-FDG PET/CT results may act as a biomarker for the presence of a BRAF mutation, aid in establishing a diagnosis, guide biopsies, and gauge the treatment response in ECD patients. Axial and pelvic skeletal involvement is greater than previously reported.

A Rare Case of Erdheim-Chester Disease and Langerhans Cell Histiocytosis Overlap Syndrome

A 48-year-old woman with a past medical history of seizures and end-stage renal disease secondary to obstructive uropathy from retroperitoneal fibrosis presented to the emergency department with seizures and altered mental status. A Glasgow Coma Scale of 4 prompted intubation, and she was subsequently admitted to the intensive care unit. Magnetic resonance imaging of the brain performed to elucidate the aetiology of her seizure showed a dural-based mass within the left temporoparietal lobe as well as mass lesions within the orbits. Further imaging showed extensive retroperitoneal fibrosis extending to the mediastinum with involvement of aorta and posterior pleural space. Imaging of the long bones showed bilateral sclerosis and cortical thickening of the diaphyses. Imaging of the maxillofacial structures showed osseous destructive lesions involving the mandible. These clinical and radiological features were consistent with a diagnosis of Erdheim-Chester disease; however, the patient's skin biopsy was consistent with Langerhans cell histiocytosis.

Erdheim-Chester Disease: A Case Report

Patient: Female, 56

Final Diagnosis: Erdheim-Chester disease

Symptoms: Slurred speech • unsteady gait • walking difficulties

Medication: —

Clinical Procedure: —

Specialty: Oncology

18F-fluoride PET/CT aspect of an unusual case of Erdheim-Chester disease with histologic features of Langerhans cell histiocytosis

We report the case of a 63-year-old woman with Erdheim-Chester disease (ECD) and histologic features of Langerhans cell histiocytosis, both extremely rare histiocytic proliferations responsible of skeletal and extraskeletal involvement. 18F-Fluoride PET/CT revealed multiple intense focal uptake scattered throughout the skeleton. We also performed an 18F-FDG PET/CT which point out visceral and vascular involvement. This case illustrates the interest of PET/CT in ECD, a rare polymorphus and systemic disease, and in our knowledge, this is the first reported illustration of 18F-fluoride PET/CT findings in this pathology.

Peculiar distribution of tumorous xanthomas in an adult case of erdheim-chester disease complicated by atopic dermatitis

Erdheim-Chester disease is a rare non-Langerhans form of histiocytosis with multiple organ involvement. Approximately 20% of patients have xanthoma-like lesions, usually on the eyelids. We report a case of Erdheim-Chester disease in a 32-year-old male who showed peculiar xanthomatous skin lesions and also had atopic dermatitis. His skin manifestations included ring-like yellowish tumors on his periorbital regions, rope necklace-like tumors on his neck, and spindle-shaped tumors on his right preauricular region and cubital fossas. He also had exophthalmos and diabetes insipidus. Chronic eczematous lesions were present on the flexor aspect of his extremities, and his serum eosinophil numbers and immunoglobulin E levels were elevated. A histological examination of his right neck tumor showed foamy macrophages and touton-type giant cells, which were positive for CD68 and CD163 and negative for S-100 and CD1a. We suggest that the complication of atopic dermatitis may have contributed to the uncommon clinical features in this case.

Non-Langerhans cell histiocytosis with isolated CNS involvement: an unusual variant of Erdheim-Chester disease

Benign histiocytic proliferations are identified by their component cells and classified as either Langerhans cell histiocytosis or non-Langerhans cell histiocytosis. We report a 58-year-old Caucasian woman who presented with diabetes insipidus and was found to harbor a large suprasellar mass. Histopathological analysis was consistent with non-LCH. The differential diagnoses included juvenile xanthogranuloma, adult-onset xanthogranuloma, xanthoma disseminatum, Rosai-Dorfman disease, and Erdheim-Chester disease. Immunohistochemical examination demonstrated a proliferation of large lipid-laden histiocytic cells which were positive for CD68, negative for S100 protein, and showed only faint, background staining for CD1a. We present a case of an autopsy-confirmed non-Langerhans cell histiocytosis limited to the central nervous system and evaluated with both immunohistochemical and ultrastructural studies. Based on the multifocality, anatomic distribution, and immunostaining features, a diagnosis of Erdheim-Chester disease was made. This is only the second reported case of Erdheim-Chester disease with intracranial involvement but absence of extracerebral manifestations. Given the overlapping clinicopathologic, radiographic, and immunohistochemical profiles, differentiating between these rare histiocytic disorders can often present a significant diagnostic challenge. A systematic approach using all available clinical, laboratory, radiographic, histologic, immunohistochemical and ultrastructural data is essential for proper discrimination between the numerous histiocytoses.

A case of osteoarthropathy due to Erdheim-Chester disease with overlapping Langerhans' cell infiltration

Histiocytosis sometimes involves the joints, and is one of the important differential diagnoses of osteoarthropathy. A 31-year-old man presented with recurrent fever and bilateral knee arthritis two years prior to admission. He also showed the hypopituitary mass lesion and partial hypopituitarism. X-ray studies showed both osteosclerotic and osteolytic lesions near the large joints. Histological findings of bone biopsy revealed foamy macrophage infiltration, which were CD68+CD1a-S100-, and Erdheim-Chester disease was diagnosed. In addition, CD68+CD1a+ Langerhans' cells also aggregated in the same lesions, and we thought this case was a rare variant of Erdheim-Chester disease with overlapping histiocytic invasion.

An unusual case of Erdheim-Chester disease with features of Langerhans cell histiocytosis

Erdheim-Chester disease (ECD) and Langerhans cell histiocytosis (LCH) are both exceedingly rare histiocytic proliferations that can involve the skeletal system. We report on a case of ECD with some features suggestive of LCH. Radiographs demonstrated a large lytic lesion in the left femur, with multiple lesions of sclerosis involving both distal femurs and tibias. Both the lytic lesion and a sclerotic lesion were biopsied and demonstrated distinctive histologic features characteristic of ECD in the tibia and features of LCH in the femur. The clinical/radiologic and pathologic features that distinguish ECD and LCH as distinct entities are reviewed, and the underlying biological connection between them is discussed.

Bone involvement in Erdheim-Chester disease: imaging findings including periostitis and partial epiphyseal involvement

PURPOSE

To retrospectively review the bone findings at radiography, scintigraphy, computed tomography (CT), and magnetic resonance (MR) imaging in 11 patients with immunohistochemical and histologic proof of Erdheim-Chester disease.

MATERIALS AND METHODS

This study was designed as a retrospective review; approval of the institutional review board and patient consent were not required for this type of study. Eleven patients (eight men and three women; mean age, 49 years; range, 17-68 years) with Erdheim-Chester disease underwent conventional radiography of the skeleton and bone scintigraphy. Two patients underwent CT of the femora and 10 underwent CT of the skull. Eight patients underwent MR imaging. Conventional radiographs, bone scintigrams, CT scans, and MR images were reviewed in consensus by four musculoskeletal radiologists.

RESULTS

All 11 patients had involvement of the long bones and normal axial skeleton, hands, and feet. Bilateral and symmetric osteosclerosis of the diaphysis of the long bones was present in 52 (26 pairs) (98%) of the 53 bone lesions visible on conventional radiographs. Osteosclerosis was heterogeneous in 65% of the patients and homogeneous in 35%. Diaphysis was involved in 100% and metaphysis in 44 (83%) lesions. Partial epiphyseal involvement sparing the subchondral bone was present in 24 (45%) lesions. Periostitis was seen in 35 (66%) and endosteitis in 50 (94%) of the 53 long bones involved. Bone scintigraphy depicted tracer uptake in all bone lesions visible on radiographs. Skull and face bone lesions were present in two patients. MR imaging depicted a replacement of the normal fatty bone marrow by heterogeneous signal intensity on T1- and T2-weighted spin-echo images. Lesion extent, epiphyseal involvement, and periostitis were clearly depicted at MR imaging.

CONCLUSION

This series provides a detailed description of bone involvement in Erdheim-Chester disease. Periostitis and partial epiphyseal involvement of the long bones are also features of this disease. (c) RSNA, 2005.

Erdheim-Chester disease: the effect of bisphosphonate treatment--a case report

Erdheim-Chester disease is a distinctive pathologic and radiographic entity characterized by bilateral symmetric sclerosis of the diametaphyseal regions of long bones and infiltration of foamy lipid-laden histiocytes. It is a rare histiocytic disease of unknown etiology that is characterized pathologically by xanthogranulomatous infiltrates of multiple organs. We present a patient in her early sixties with bilateral mild knee and leg pain. The patient showed a typical bilateral symmetric medullary sclerosis at the diametaphyseal portions of long bones of the lower extremity. The diagnosis was confirmed by a bone biopsy, and bisphosphonate (alendronate, 70 mg/wk) was given to the patient. After 9 months of treatment, biochemical markers of bone turnover, which were high at baseline, decreased to normal ranges. However, the radiographs showed that bone lesions had changed to lytic lesions. We propose use of bisphosphonates, such as alendronate, to decrease the biochemical markers of bone turnover. But we suggest that it is premature to conclude that bisphosphonates have any effect on lytic lesions and the progression of the disease as shown by changes in radiographs. Further studies with long-term follow-up and ultrastructural evaluation are needed.

Pulmonary involvement in Erdheim-Chester disease

Erdheim-Chester disease is a disseminated non-Langerhans' cell histiocytosis involving multiple organs with characteristic sclerotic musculoskeletal lesions. This is the report of the case of a 53-year-old woman with extensive and progressive pulmonary disease. Computed tomography scans revealed diffuse infiltrative lung disease. Thoracoscopic lung biopsy and a biopsy of the right femur lesion were performed. The histopathology revealed that she had non-Langerhans' cell histiocytosis; Erdheim-Chester disease. The characteristic lesions of Erdheim-Chester disease, including involvement of the orbit, pericardium, periaorta, and bone were detected. This helped to further confirm that the patient had Erdheim-Chester disease with associated pulmonary involvement. As Erdheim-Chester disease is a rare non-Langerhans' cell histiocytosis that may be misdiagnosed as interstitial lung disease or other pulmonary disorders, this diagnosis should be considered in the differential diagnosis of such lung lesions.

Erdheim-Chester disease versus multifocal fibrosis and Ormond's disease: a diagnostic dilemma

AIM

The aim of the study was to evaluate the effectiveness of different imaging techniques with respect to diagnosis and differential diagnosis between Erdheim-Chester disease (ECD) and multifocal fibrosis (MF)/Ormond's disease (OD).

METHOD

Three cases of ECD were included, two of which were misdiagnosed as MF/OD. Findings in different imaging techniques [plain radiography, skeletal scintigraphy, computed tomography (CT) and magnetic resonance imaging (MRI)] of the lower extremities, chest MRI, craniofacial MRI, abdominal CT and MRI) were compared and ranked with regard to diagnostic efficacy.

RESULTS

Differentiation between ECD and MF/OD is only possible by imaging the long bones. Bone roentgenograms and skeletal scintigraphy, followed by MRI and CT of the lower extremities are the most effective imaging techniques.

CONCLUSION

A low threshold for carrying out plain radiography of the lower limbs in case of RF/MF will increase the number of ECD-cases.

Erdheim?Chester disease of the breast associated with Langerhans-cell histiocytosis of the hard palate

We report a patient with Langerhans-cell histiocytosis (LCH) localized to the hard palate that was later proven to be associated with Erdheim-Chester disease (ECD), involving the right breast, skeleton, retroperitoneum and left orbit. The diagnosis was based on the symmetric osteosclerosis of the long bones diaphyses (tibias and fibulas), breast lump histopathological/immunohistochemical findings and retroperitoneum and left orbit images in magnetic resonance. Mammary involvement by ECD is an extremely rare condition, which should be differentiated from some benign and malignant mimickers, especially the histiocytoid type of breast carcinoma. Characteristic histological features plus clinical and radiographic information are needed to achieve a correct diagnosis. The ECD, its relation to the LCH and details of the breast lesion are discussed.

Erdheim-Chester disease

A 38-year-old man presented with numerous dermal nodules, similar to xanthoma disseminatum, that were histologically consistent with his diagnosis of Erdheim-Chester disease, a non-Langerhans cell histiocytosis. Other cutaneous manifestations of this disease include eyelid xanthelasma, pretibial dermopathy and pigmented lesions of the lips and buccal mucosa. The histological diagnosis of Erdheim-Chester disease was originally made on the patient's retroperitoneal tissue, obtained at a laparotomy for surgical treatment of a presumed phaeochromocytoma, and confirmed by the pathognomonic long bone X-ray findings of this disease.

Erdheim-Chester disease: a unique presentation with liver involvement and vertebral osteolytic lesions

Erdheim-Chester disease is a very rare xanthogranulomatous, non-Langerhans cell systemic histiocytosis with an unknown etiology and pathogenesis. Histologically, it is characterized by a diffuse infiltration with large, foamy histiocytes, rare Touton-like giant cells, lymphocytic aggregates, and fibrosis. The histiocytes differ from the Langerhans cell group in ontogenesis, immunohistochemistry (positive for CD68 and negative for CD1a and S100 protein), and ultrastructural appearance (lack of Birbeck granules). Although most of the cases have symmetric osteosclerosis of the long bones, an involvement of the axial skeleton has also been described. Extraskeletal lesions are present in more than 50% of the patients and may involve the retroperitoneal space, lungs, kidneys, brain, retro-orbital space, and heart. This study presents the case of a patient with Erdheim-Chester disease with vertebral destruction and, for the first time, to our knowledge, involvement of the liver. The diagnosis is based on radiologic, histologic, immunohistochemical, and ultrastructural findings.

Multiple system Erdheim-Chester disease with massive hypothalamic-sellar involvement and hypopituitarism

Erdheim-Chester disease (ECD) is a rare multiple system histiocytosis that is characterized pathologically by xanthogranulomatous infiltrates and radiologically by symmetrical sclerosis of long bones. The diagnosis is often confirmed by biopsy of bone or of orbital or retroperitoneal soft tissue. Intracranial involvement is rare. The authors report a case of ECD in which the diagnosis was made after biopsy of a hypothalamic mass. The mass had been discovered during a workup for panhypopituitarism in a 55-year-old man with urological and bone disease. Aside from diabetes insipidus, other features of pituitary insufficiency have seldom been reported and no patients have presented with a hypothalamic tumor. The endocrinological and neurological aspects of ECD are discussed, as is its differential diagnosis. Reported cases of the disorder associated with hypopituitarism or found during biopsy of central nervous system structures are also reviewed.

Erdheim-Chester disease with extensive marrow necrosis: a case report and literature review

Erdheim-Chester disease is a rare systemic disorder characterized by a fibrosing xanthogranulomatous infiltration of multiple organs. We report a case of Erdheim-Chester disease with diffuse necrosis leading to difficulty in making a prompt diagnosis. Radiologically, osteosclerotic lesions with osteolytic element involved metadiaphyses of both proximal tibia, and retroperitoneal infiltrations encasing both kidneys, both adrenals, and aorta were found. A biopsy of the tibia showed diffuse infiltration of foamy histiocytes, Touton-type giant cells, and fibroblastic cells associated with extensive coagulative necrosis. Immunohistochemically, foamy histiocytes were positive for CD68 and peanut agglutinin and negative for S-100 protein. A few Langerhans' cells, which were difficult to identify in hematoxylin-eosin stain, were highlighted by immunostain for S-100 protein. The patient received supportive therapy and was alive 1 1/2 years after diagnosis, with newly developed bilateral retrobulbar lesions and worsened heart failure.

Erdheim-Chester disease: a rare multisystem histiocytic disorder associated with interstitial lung disease

Erdheim-Chester disease (ECD) is a rare multisystem histiocytosis syndrome of unknown cause that usually affects adults. Histiocytic infiltration of multiple end organs produces bone pain, xanthelasma and xanthoma, exophthalmos, diabetes insipidus, and interstitial lung disease. Differential diagnosis includes Langerhans cell histiocytosis, metabolic disorders, malignancy, and sarcoidosis. ECD can be diagnosed using a combination of clinical and histopathologic findings. Sites of involvement include lung, bone, skin, retroorbital tissue, central nervous system, pituitary gland, retroperitoneum, and pericardium. Symmetrical long bone pain with associated osteosclerotic lesions, xanthomas around the eyelids, exophthalmos, and/or diabetes insipidus suggest ECD. Approximately 35% of patients have associated lung involvement, characterized by interstitial accumulations of histiocytic cells and fibrosis in a predominantly perilymphangitic and subpleural pattern. This pattern distinguishes ECD from other histiocytic disorders involving the lung. The diagnosis is confirmed by tissue biopsies that contain histiocytes with non-Langerhans cell features. In general, the clinical course of patients with this disease varies, and the prognosis can be poor despite treatment. Clinical trials for treatment of ECD have not been conducted and treatment is based on anecdotal experience.

Erdheim-Chester disease of the jaws: literature review and case report

Erdheim-Chester disease is a rare systemic lipogranulomatous disorder of adults that shares some histopathologic features similar to Langerhans' cell histiocytosis and that results in characteristic radiographic changes in the long bones. Relatively few cases have been reported in the jaws. We present a literature review of jaw cases and the first case report to describe detailed radiographic and pathologic features of jaw involvement, as well as clinical, radiographic, and histopathologic follow-up of the untreated jaw lesions.

The role of bone scintigraphy in patients with Erdheim-Chester disease

Erdheim-Chester disease (ECD) is a rare disorder that has been reported fewer than 60 times in the literature. Although clinical findings seem to be specific at first sight, histologic classification remains unclear. It has not been decided whether ECD is part of the spectrum of histiocytoses or whether it may be a lipid storage disorder or even a primary macrophage cell disorder, although it does show a distinct histologic pattern. However, the clinical appearance alone shows several typical features, rendering the diagnosis very probable if present. This article illustrates the importance of bone scanning in ECD, because the scintigraphic pattern of involved skeletal sites may in themselves lead to the diagnosis. Several differential diagnoses are considered. The importance of bone scintigraphy as an imaging method in patients with an unclear diagnosis is discussed, as exemplary in ECD, as is its role for the detection of sites of skeletal involvement in other diseases.

Pulmonary involvement with Erdheim-Chester disease: radiographic and CT findings

OBJECTIVE

We determined the chest radiographic and CT findings of Erdheim-Chester disease with pulmonary involvement.

MATERIALS AND METHODS

We retrospectively reviewed the radiologic images of 15 patients with biopsy-proven Erdheim-Chester disease. Nine patients had chest radiographic images and CT scans that were available for review. Six men and three women were studied (age range, 25-70 years; mean age, 56 years). Two radiologists interpreted all images by consensus. Lung parenchyma was assessed for the type and distribution of disease. Bronchi, pleurae, hila, and mediastinal and extrathoracic structures were evaluated for abnormalities. Pathologic specimens from all patients were reviewed and correlated with radiologic findings.

RESULTS

Eight of nine patients had thoracic images with abnormal findings. The most common radiographic pattern was reticular interstitial opacities with fissural and interlobular septal thickening. CT revealed regions of ground-glass attenuation and centrilobular nodular opacities. Typically, extrapulmonary findings included pleural effusions (6/8 patients), pericardial fluid or thickening (4/8), and extrathoracic infiltrative soft-tissue masses (4/8).

CONCLUSION

The most common findings of Erdheim-Chester disease with pulmonary involvement include an interstitial process characterized by smooth interlobular septal thickening and centrilobular nodular opacities, fissural thickening, and pleural effusions. On CT, six of nine patients had pericardial fluid and thickening or extrathoracic soft-tissue masses. Such findings are characteristic of Erdheim-Chester disease with pulmonary involvement. Definitive diagnosis requires correlating skeletal findings and lung biopsy findings.

Chester-Erdheim disease: a neoplastic disorder

Chester-Erdheim disease is a rare non-langerhans cell histiocytosis characterized by a xanthomatous infiltration of foamy macrophages. The cause and pathogenesis remain unclear. The aim of the present study was to determine whether Chester-Erdheim disease is a polyclonal reactive disease or a clonal neoplastic disorder. The clonal status of samples obtained from five patients with Chester-Erdheim disease was studied. DNA was extracted from fixed and paraffin-embedded sections after microdissection and clonal status was studied using the Xchromosome inactivation pattern of the human androgen receptor gene (HUMARA assay). One patient was homozygous for the HUMARA gene and noninformative. Three other cases were monoclonal. One was polyclonal, and this case showed a dense reactive infiltrate in association with spumous macrophages. This study suggests strongly that Chester-Erdheim disease is a monoclonal lesion consistent with neoplastic disorder. Thus, Chester-Erdheim disease may be considered as the "macrophage" counterpart of Langerhan's cell histiocytosis in the histiocytosis spectrum. Further studies are needed to establish the origin of this clonal proliferation.

Determination of extent and activity with radionuclide imaging in Erdheim-Chester disease

Erdheim-Chester disease usually involves the diaphyseal and metaphyseal regions of tubular bones and various visceral organs. A 56-year-old woman presented with the histologically confirmed diagnosis of Erdheim-Chester disease. A Tc-99m MDP bone scan revealed the entire extent of the skeletal disease and showed unusual involvement of the epiphyses and axial skeleton. In addition to MRI, a Ga-67 citrate scan including SPECT showed extensive soft-tissue infiltration of different organs. Both Tc-99m MDP and Ga-67 scintigraphy are useful tools in determining the distribution of this rare disease.

Erdheim-Chester disease. Clinical and radiologic characteristics of 59 cases

We made a retrospective evaluation of clinical and radiologic features, treatment, and outcome of Erdheim-Chester disease, a rare non-Langerhans cell histiocytosis. We had 7 patients coming from 3 French teaching hospitals and reviewed 52 cases from the literature. These cases were considered to have Erdheim-Chester disease when they had either typical bone radiographs (symmetrical long bones osteosclerosis) and/or histologic criteria disclosing histiocytic infiltration without features for Langerhans cell histiocytosis (no S-100 protein, no intracytoplasmic Birbeck granules). Ages at diagnosis ranged from 7 to 84 years (mean +/- SD = 53 +/- 14 yr) with a male/female ratio of 33/26. Bone pain was the most frequent clinical sign (28/59), mostly located in the lower limbs. Exophthalmos and diabetes insipidus were found in respectively 16/59 and 17/59 patients. General symptoms (fever, weight loss) and "xanthomas" (mainly located on the eyelids) were present in 11/59 patients. Retroperitoneal involvement was found in 17/59 patients. Skeletal X-ray showed typical osteosclerosis of the diaphysis of the long bones in 45/59 patients. Bone radiographs showed osteolytic lesions of the flat bones (skull, ribs) in 8 patients. Histologic diagnosis was performed after a bone biopsy (28 patients), a retroorbital biopsy (9 patients), and/or a biopsy of the retroperitoneal infiltration or the kidney (11 patients). Six of our 7 patients but only 5 of 52 patients from the literature had the complete histologic criteria, disclosing no Birbeck granules or S-100 immunostaining. In other cases, histologic results usually described a xanthogranulomatous infiltration by foamy histiocytes nested in fibrosis. Treatment was corticotherapy (20/59), chemotherapy (8/59), radiotherapy (6/59), surgery (3/59) and immunotherapy (1 patient). Twenty-two patients died after a mean follow-up of 32 +/- 30 mo (range, 3-120 mo). In conclusion, Erdheim-Chester disease may be confused with Langerhans cell histiocytosis as it sometimes shares the same clinical (exophthalmos, diabetes insipidus) or radiologic (osteolytic lesions) findings. However, it also appears to have distinctive features. Patients are older and have a worse prognosis than those with Langerhans cell histiocytosis, and the diagnosis relies on the association of specific radiologic and histologic findings.

Implant rehabilitation in Erdheim-Chester disease: a clinical report

Successful osseointegration of endosseous titanium implants is thought to be dependent upon close apposition of bone to the implant surface. The integration of implants in this patient was achieved despite the lipid-laden histiocytic infiltration of the bone marrow. Presumably, enough unaffected stromal cells were present to allow sufficient bone formation for osseointegration of the implant fixtures. This result invites speculation regarding both the mechanism of osseointegration and the minimum surface area of bone-implant interface necessary for achieving and maintaining osseointegration of titanium implants. This patient is periodically examined to determine if the loaded fixtures will remain clinically immobile for a prolonged period.

Premature alveolar bone loss in Erdheim-Chester disease

Erdheim-Chester disease is a rare histiocytosis also known as lipoid granulomatosis. Oral findings have not been reported previously to our knowledge. This case report documents evidence of oral sequelae of Erdheim-Chester disease. A patient whose course was followed for 10 years at the National Institutes of Health had premature alveolar bone resorption. He underwent full-mouth extraction at age 29 years because of severe periodontitis. Histopathologic evidence of Erdheim-Chester disease was demonstrated in the periodontal soft tissues. In the ensuring years, accelerated resorption of the residual ridges precluded the use of conventional dentures. We recommend early preventive dental management for patients with Erdheim-Chester disease.

Scintigraphic findings and follow up in Erdheim-Chester disease

Two cases of Erdheim-Chester disease are presented: a 26-year-old white male patient with lipoidgranulomatosis of numerous long and flat bones and infiltration of pericardium, pleura, liver, spleen, thyroid, skin, conjunctiva, gingiva, and false vocal cord; and a 54-year-old white male with involvement of bones, orbits, brain, pericardium, and retroperitoneum. The scintigraphic findings in this disease are described, and a comprehensive review of the 27 previously reported cases is given including an assessment of the value of scintigraphy for diagnosis and follow up of this rare disease.