A rare case of Erdheim Chester disease.

Erdheim-Chester disease (ECD) is a rare form of non-Langerhans cell histiocytosis. There are few documented cases in the medical literature. Here, we present an infrequent case of a 53-year-old patient who presented with cutaneous xanthelasma and a gradual decline in general health characterized by asthenia, anorexia, and chronic dyspnea over the last 5 years. Chest, abdominal, and pelvic CT scans revealed distinct findings suggestive of ECD, including peri-renal fat infiltration resulting in the "hairy kidney" sign, hepatosplenomegaly, renal artery ostial stenosis, pneumopericardium thickening, interstitial lung parenchymal involvement, metaphyseal-diaphyseal osteosclerosis affecting long bones, and sinus osteosclerosis. A biopsy confirmed the diagnosis. This case highlights the importance of radiologists being familiar with the characteristic radiologic signs of ECD to avoid unnecessary repeat examinations, delays in diagnosis, or misdiagnosis.

Erdheim-Chester disease: An elusive diagnosis in a 50-year-old Ethiopian man presenting with diffuse sclerotic bone lesion.

Key Clinical Message: Diagnosis of Erdheim-Chester disease (ECD) requires the clinician to be familiar with its various manifestations, classic radiologic and histologic features. This case highlights the significance of considering ECD in any patient presenting with bone pain and symmetric osteosclerosis of long bones of extremities to allow for early diagnosis and treatment. Abstract: Erdheim-Chester disease (ECD) is a rare non-Langerhans histiocytic disorder with diverse clinical manifestations, ranging from indolent, localized presentation to life-threatening, multi-systemic disease. Delayed or erroneous diagnosis is common. The presence of classic radiographic finding along with foamy histiocytes that is positive for CD68 but negative for CD1a on histologic examination establishes the diagnosis. We report a second case of ECD from Ethiopia. A 50-year-old Ethiopian man presented with a 13-year history of bilateral lower leg bone pain, cold intolerance, somnolence, constipation, impotence, decreased libido, and secondary infertility. The diagnosis was suspected when skeletal X-ray revealed bilateral symmetric sclerosis of metadiaphysis of femur, tibia, and humerus. The demonstration of foamy histiocytes that were positive for CD68 but negative for CD1a on histologic examination with immunohistochemical staining confirmed the diagnosis. Evaluation for the extent of the disease revealed coated aorta sign, hairy kidney sign, and cystic lesion with ground glass opacity of lung, primary hypothyroidism, and hypergonadotropic hypogonadism. ECD is rare histiocytic neoplasm with wide range of clinical features which often delay the diagnosis. Clinician should be mindful of the various presentations and the classic radiographic and histologic features of ECD. This case highlights the significance of entertaining ECD in any patient presenting with lower leg bone pain and symmetric osteosclerosis of long bones of lower extremities to allow for early diagnosis and treatment.

Pulmonary Langerhans cell histiocytosis with multiple cavitary nodules after lung cancer surgery.

Pulmonary Langerhans cell histiocytosis (PLCH) is a subtype of Langerhans cell histiocytosis, a rare neoplastic disease characterized by lung involvement. Here, we present a case involving a patient with multiple cavitary nodules who was diagnosed with PLCH during surveillance after lung cancer surgery. A 74-year-old woman underwent right upper lobe resection surgery for right upper lobe lung adenocarcinoma, pStage IIA, 5 years ago. The patient underwent surveillance without adjuvant chemotherapy. During the fifth year of follow-up, multiple nodules with cavitation were observed on computed tomography in both lung fields. Chemotherapy was considered to address the suspected recurrence of lung cancer; however, video-assisted thoracoscopic surgery was performed due to the need for biomarker testing. Pathological examination led to the diagnosis of PLCH. This case emphasizes the importance of a proactive histological diagnosis to determine the appropriate treatment strategy, even in situations where lung cancer recurrence is clinically suspected.

The clinical impact of serum soluble CD25 levels in children with Langerhans cell histiocytosis.

OBJECTIVE: Langerhans cell histiocytosis (LCH) is a rare myeloid neoplasm with inflammatory characteristics. This study aims to investigate the correlation between sCD25 levels and clinical characteristics, as well as prognosis, in pediatric LCH. METHODS: Serum sCD25 levels were measured in 370 LCH patients under 18 years old using ELISA assays. The patients were divided into two cohorts based on different treatment regimens. We further assessed the predictive value for the prognosis impact of sCD25 in a test cohort, which was validated in the independent validation cohort. RESULTS: The median serum sCD25 level at diagnosis was 3908 pg/ml (range: 231-44 000pg/ml). sCD25 level was significantly higher in multi-system and risk organ positive (MS RO+) LCH patients compared to single-system(SS) LCH patients (p < 0.001). Patients with elevated sCD25 were more likely to have involvement of risk organs, skin, lung, lymph nodes, or pituitary (all p < 0.05). sCD25 level could predict LCH progression and relapse, with an area under the ROC curve of 60.6 %. The optimal cutoff value was determined at 2921 pg/ml. Patients in the high-sCD25 group had significantly worse progression-free survival compared to those in the low-sCD25 group (p < 0.05). CONCLUSION: Elevated serum sCD25 level at initial diagnosis was associated with high-risk clinical features and worse prognosis. sCD25 level can predict the progression/recurrence of LCH following first-line chemotherapy.

Utility of MR spectroscopy and MR perfusion in characterizing intracranial pathology in Erdheim-Chester disease: A case report.

This case report describes the potential utility of MR spectroscopy and MR perfusion imaging in a patient with central nervous system involvement of Erdheim-Chester disease (ECD). A 57-year-old male presented with a variety of neurological symptoms, and conventional MRI of the brain showed multiple supratentorial and infratentorial findings that generated a wide differential diagnosis. Advanced MRI sequences along with subsequent CT imaging of the abdomen and ultimately a renal biopsy helped narrow the differential and confirm the diagnosis of ECD. Case reports of ECD are sporadic, and the role of advanced neuroimaging in diagnosing this disease has not been fully elucidated.

Case of pulmonary Langerhans cell histiocytosis presenting as ground-glass opacity in the lower lung.

Nodules and cysts with upper lobe predominance on chest computed tomography (CT) are highly suggestive of pulmonary Langerhans cell histiocytosis (PLCH). Herein, we describe a case of PLCH that presented with the unusual CT findings of subpleural ground-glass opacity (GGO) and traction bronchiectasis mostly in both lower lungs. No nodules or cysts were observed in the upper or middle lung areas. Video-assisted thoracoscopic biopsies were performed at the right lower lobe. Biopsy specimens showed findings consistent with those of scarred PLCH. To the best of our knowledge, this is the first case of PLCH presenting as GGO in the lower lungs.

Rosai-Dorfman disease presenting as a perirectal mass: A case report and review of diagnostic challenges.

An uncommon benign histiocytic illness, Rosai-Dorfman disease (RDD) mostly affects lymph nodes but can also manifest as extranodal involvement. We describe a case of a female patient, sixty years of age, who had joint discomfort, sleeplessness, weight loss, and headache and eye problems. A heterogeneously hypodense perirectal mass was seen on imaging. Other histiocytic diseases, metastatic cancer, and lymphoma were among the differential diagnosis. Through biopsy and immunohistochemistry staining, which revealed S-100 and CD68 positivity with CD1a negative, a definitive diagnosis of RDD was made. Over a 2-year period following surgical excision, the patient's symptoms significantly improved and there was no sign of recurrence. This example emphasizes the significance of taking RDD into account when making a differential diagnosis for perirectal tumors and the function of imaging in conjunction with histological testing in guiding management.

Erdheim-Chester Disease Presenting as Bilateral Facial Masses: A case report and review of literature.

Erdheim-Chester disease (ECD) is a rare form of non-Langerhans cell histiocytosis with unknown aetiology. It is recently recognised to be neoplastic with genetic mutations affecting the mitogen-activating protein kinase pathway. We report a 49-year-old female patient who initially presented in 2012 to a tertiary care centre in Muscat, Oman, with bilateral facial masses. These were removed but later recurred over a period of 10 years. She then presented with xanthelasmas, bone lesions, secondary infertility due to hypothalamic hypogonadism, diabetes insipidus and Hashimoto's hypothyroidism. The facial masses were biopsied and they showed classic morphological features in the form of diffuse infiltration by foamy histiocytes with scattered Touton type of giant cells, patchy lymphocytic infiltrates and dense fibrosis. The patient is stable and is being followed-up. The presented ECD case is particularly interesting due to the recurrent bilateral facial masses. To the best of the authors' knowledge, this is the first documented case in Oman.

A Case of Spontaneous Regression of Adult Multi-system Langerhans Cell Histiocytosis Presenting as Liver Tumor Rupture.

Adult multisystem Langerhans cell histiocytosis (MS-LCH) is rare and has a poor prognosis. A 67-year-old man with MS-LCH presented with a hepatic tumor rupture and multiple masses in the lungs, liver, and pancreas. Despite the initial aggressive disease course and involvement of organs at risk, the patient experienced spontaneous regression and lesion disappearance following smoking cessation without chemotherapy. A literature review revealed a distinct subset of MS-LCH that can be managed by smoking cessation and careful observation through follow-up imaging. This suggests that careful observation through follow-up imaging may be a reasonable alternative to chemotherapy in select adult cases of MS-LCH.

Incidentally Detected ALK-Positive Histiocytosis with EML4::ALK Fusion in a Solitary Pulmonary Nodule Following COVID-19 Infection: A Rare Case Report.

We hereby report a patient with ALK-positive histiocytosis with localized lung involvement. A 47-year-old woman presented with a solitary pulmonary nodule in the left upper lobe, 7 months after COVID infection. A well-defined 15 mm yellow mass was found in trisegmentectomy specimen. Histopathological examination revealed that the mass was composed of epithelioid and spindle cells with foamy cytoplasms. No necrosis, pleomorphism, or nuclear atypia was detected. The cells were positive for CD68, CD163, PU.1, ALK and negative for KRT, smooth muscle actin (SMA), S100, Melan-A, CD34, STAT6, and BRAF VE1. Flourescence in situ hybridization demonstrated ALK gene rearrangement, and next generation sequencing confirmed EML4::ALK fusion. Lung involvement in ALK-positive histiocytosis is characterized by the presence of pulmonary nodules, which can be seen in all forms of the disease. However, lung involvement is rarely seen in single-system ALK-positive histiocytosis. Our report represents the fourth documented instance of localized lung involvement in ALK-positive histiocytosis, an exceedingly rare occurrence, and it is the third instance with available molecular data.

Challenges in diagnosis and management of Langerhans Cell Histiocytosis in a 13-month-old child: a rare case report.

Introduction: Langerhans Cell Histiocytosis is a rare condition characterized by the proliferation of abnormal Langerhans cells in the skin and mucosa. It is mostly seen in children between 1 and 3 years old. Although the skeleton accounts for 80% of infiltration and the skin accounts for 33%, it can affect other organs as well. Case presentation: The authors report a case of a 13-month-old male with fever, rash, and nontender swelling in the frontal, temporal, and infraorbital regions. Imaging showed diffusion restriction in the frontal, left parietal, right sphenoid, right temporal bones, and right maxillary antrum. Biopsy and immunohistochemistry from the right maxilla confirmed the diagnosis. The patient was treated with vinblastine and prednisolone for 3 months, resulting in reduced swelling and no fever on follow-up. Discussion: Langerhans Cell Histiocytosis (LCH), formerly Histiocytosis X, has diverse clinical manifestations and is classified as localized or disseminated based on organ involvement. It is associated with viral infections, communication defects, and cytokine processes, with BRAF mutations and the MAPK/ERK pathway implicated. Diagnosis involves clinical, radiological, histological, and immunophenotypic methods, including identifying Birbeck granules in Langerin-positive cells. Treatment varies by disease extent, with vinblastine and prednisolone for children with multisystem disease and tailored approaches for adults. Conclusion: Despite atypical presentation, thorough evaluation confirmed Langerhans Cell Histiocytosis in a pediatric patient. This highlights the necessity of considering Langerhans Cell Histiocytosis in differential diagnoses for persistent cutaneous lesions and bony swellings. Prompt detection and timely action are essential for successful treatment and better results.

ALK-positive histiocytosis: Report of a rare case with exclusive involvement of the central nervous system in an adult woman.

ALK-positive histiocytosis is a rare histiocytic disease characterized by ALK positivity. It was first described in 2008 as a systemic disease in infants. The disease often shows positivity for CD68 and CD163 on immunohistochemistry, and genomic analysis frequently reveals KIF5B::ALK fusions. ALK-positive histiocytosis typically follows an indolent course and has a promising prognosis, with conventional treatments usually being effective. Here, we report a rare case of ALK-positive histiocytosis with exclusive involvement of the central nervous system in a 33-year-old Asian adult woman. Although cranial MRI suggested a meningioma, immunohistochemical workup showed that the ALK-positive tumor cells expressed macrophage/histiocyte markers such as CD163 and CD68. Additionally, second-generation sequencing revealed a KIF5B::ALK fusion. Our case highlights the importance of the differential diagnosis in adult central nervous system tumors, emphasizing the combination of morphology, immunophenotype, and molecular approach with ALK status evaluation to confirm a diagnosis of ALK-positive histiocytosis. This case also expands the clinicopathologic spectrum of ALK-positive histiocytosis.

Subglottic adenoid cystic carcinoma associated with pulmonary Langerhans cell histiocytosis.

Pulmonary Langerhans cell histiocytosis can be associated with subglottic adenoid cystic carcinoma.

Adult Langerhans cell histiocytosis with multi­system bone, skin, lung and liver involvement: A case report.

Langerhans cell histiocytosis (LCH) is a rare neoplastic disorder marked by the uncontrolled proliferation and accumulation of immature myeloid dendritic cells, which originate from the bone marrow. Although LCH can involve various organs, including bone, lymph nodes and skin, multi-system bone, liver and lung involvement with LCH is rare in adults. A case of a 49-year-old man diagnosed with multi-system, aggressive LCH involving bone, skin, lung and liver is presented in the present study. The initial radio-clinic presentation of the patient was initially suggestive of a bone tumor. The current case report aims to draw attention to this rare disease and discuss the diagnostic approach and therapeutic management, which should be noted to help physicians more rapidly identify, diagnose and treat comparable cases.

Unravelling diagnostic challenges: A case report of pulmonary langerhans cell histiocytosis with atypical radiologic presentation.

This clinical case highlights the diagnostic challenges encountered in a young adult smoker presenting with undifferentiated pulmonary nodules. Initial investigations were inconclusive, necessitating surgical lung biopsy due to the nodules' size and location. The histopathological examination revealed pulmonary Langerhans cell histiocytosis (PLCH). This emphasizes the importance of considering PLCH in the differential diagnosis of pulmonary nodules, particularly in smokers. Moreover, it underscores the value of surgical biopsy in cases where other diagnostic techniques are limited. Early recognition and accurate diagnosis are crucial for optimal management and outcomes in PLCH.

A multidisciplinary non-invasive approach to monitor response to intravenous immunoglobulin treatment in neurodegenerative Langerhans cell histiocytosis: a real-world study.

Aims: Early detection and treatment of neurodegenerative Langerhans cell histiocytosis (ND-LCH) have been suggested to prevent neurodegenerative progression. The aim of the study is to validate a standardized multidisciplinary diagnostic work-up to monitor the intravenous immunoglobulins (IVIG) treatment response and the natural course of the disease in untreated patients. Methods: Patients with abnormal somatosensory evoked potentials (SEPs) received monthly 0.5 g/kg IVIG. The diagnostic protocol included structural 3T MRI, neurological examination, brainstem auditory evoked potentials (BAEPs) and SEPs. Results: Twenty-two patients were followed for 5.2 years (median) from the first MRI evidence of ND-LCH. Eleven patients received IVIG for 1.7 years (median). At treatment start neurological examination was abnormal in 10 patients, of whom two had severe clinical impairment and four had abnormal BAEPs. At last follow-up, 1/11 remained stable and 7/11 improved, while worsening of neurological or neurophysiological findings, or both, occurred in 3/11. Risk factors for worsening were a severe clinical or MRI ND-LCH at treatment initiation and prolonged exposure to LCH. Of the 11 untreated patients, none improved and three worsened. Conclusions: Using a standardized diagnostic protocol, we demonstrated that IVIG treatment can lead to clinical stabilization or improvement in all pauci-symptomatic patients with an MRI grading of less than 4.

ALK-positive histiocytosis in 12 Asian children.

Anaplastic lymphoma kinase-positive histiocytosis, first reported in 2008, is a rare, novel type of neoplasm. To date, no more than 100 cases of anaplastic lymphoma kinase-positive histiocytosis have been reported. In this retrospective study, 12 cases of anaplastic lymphoma kinase-positive histiocytosis, including clinical symptoms, histological features, molecular pathology, treatment, and prognosis, in children were analyzed to gain a deeper understanding of the disease. All patients were Asian children, aged 2 months to 8 years and 2 months (mean 3.1 years), and the male-to-female ratio was 5:7. All patients were followed up closely. One patient died during the follow-up period, seven (case 1-7) had focal anaplastic lymphoma kinase-positive histiocytosis, and five (case 8-12) had multisystem anaplastic lymphoma kinase-positive histiocytosis. In addition, we report the case of a patient who benefited from anaplastic lymphoma kinase-targeted therapy and a patient with the rare EML4-ALK fusion gene. The current study is expected to substantially contribute to increasing the awareness of anaplastic lymphoma kinase-positive histiocytosis.

Remission of necrobiotic xanthogranuloma after intravenous immunoglobulin interruption: A case report.

Necrobiotic xanthogranuloma is a rare non-Langerhans cell histiocytosis with the potential for multisystemic involvement. It's a challenging disease to treat and multiple treatments have been reported in the literature with variable results. We present the case of a 92-year-old woman with multiple orange-brown papules and plaques on her face progressing for several years. The biopsy showed dermal xanthogranulomatous infiltration with multinucleated giant cells and necrobiosis, and she was diagnosed with necrobiotic xanthogranuloma. A complete response was obtained with intravenous immunoglobulins and she remained in remission despite treatment discontinuation.