Diagnosis Of Langerhans Cell Histiocytosis Research Articles

RARE CASE OF LANGERHANS CELL HISTIOCYTOSIS IN AN ELDERLY PATIENT

Langerhans cell histiocytosis (LCH) is a disease in which there is proliferation of dendritic mononuclear cells with local or diffuse infiltration of the organs. Most cases occur in children. Oral manifestations are common and include mucosal ulcerations, bone involvement, periodontal disease, and granulomas. The diagnosis is based mainly on histologic analysis. A 75-year-old male patient reported for consultation with the main complaint of mouth sores that do not heal. Clinical examination revealed ulcerated lesions on the hard palate and alveolar ridge of the posterior teeth and the presence of teeth with bone loss and mobility. Incisional biopsy was performed and the anatomopathologic examination confirmed the diagnosis of LCH. Complementary exams were requested for staging and therapeutic definition. Therefore, it is necessary for the dental surgeon to know the characteristics of this disease and include them in the differential diagnosis of lesions that affect the oral cavity.

An in-depth discussion of cholesteatoma, middle ear Inflammation, and langerhans cell histiocytosis of the temporal bone, based on diagnostic results.

ObjectiveThis study aimed to conduct an in-depth investigation of the learning framework used for deriving diagnostic results of temporal bone diseases, including cholesteatoma and Langerhans cell histiocytosis (LCH). In addition, middle ear inflammation (MEI) was diagnosed by CT scanning of the temporal bone in pediatric patients.DesignA total of 119 patients were included in this retrospective study; among them, 40 patients had MEI, 38 patients had histology-proven cholesteatoma, and 41 patients had histology-proven LCH of the temporal bone. Each of the 119 patients was matched with one-third of the disease labels. The study included otologists and radiologists, and the reference criteria were histopathology results (70% of cases for training and 30% of cases for validation). A multilayer perceptron artificial neural network (VGG16_BN) was employed and classified, based on radiometrics. This framework structure was compared and analyzed by clinical experts according to CT images and performance.ResultsThe deep learning framework results vs. a physician’s diagnosis, respectively, in multiclassification tasks, were as follows. Receiver operating characteristic (ROC) (cholesteatoma): (0.98 vs. 0.91), LCH (0.99 vs. 0.98), and MEI (0.99 vs. 0.85). Accuracy (cholesteatoma): (0.99 vs. 0.89), LCH (0.99 vs. 0.97), and MEI (0.99 vs. 0.89). Sensitivity (cholesteatoma): (0.96 vs. 0.97), LCH (0.99 vs. 0.98), and MEI (1 vs. 0.69). Specificity (cholesteatoma): (1 vs. 0.89), LCH (0.99 vs. 0.97), and MEI (0.99 vs. 0.89).ConclusionThis article presents a research and learning framework for the diagnosis of cholesteatoma, MEI, and temporal bone LCH in children, based on CT scans. The research framework performed better than the clinical experts.

Consensus on the diagnosis of langerhans cell histiocytosis

朗格汉斯细胞组织细胞增生症是一种未成熟树突状细胞异常增生导致的肿瘤性疾病，被收录在第一批罕见病目录中。该肿瘤多见于儿童，临床表现多样，全身各器官及系统均可受累。本共识涵盖了临床、影像、组织学形态、分子生物学特点等内容，旨在提高病理诊断的精确性，更好地指导临床治疗。.

Does Fractal Analysis Have a Role in Diagnosis of Langerhans Cell Histiocytosis?

Langerhans cell histiocytosis (LCH) of the jaws is a rare disease and is often diagnosed at an advanced stage. This study aims to assess the trabecular pattern of jaws via fractal analysis (FA) on initial panoramic radiographs (OPG) of the patients with LCH to facilitate interpretation of the radiographic changes. A case-control study investigated LCH cases with jaw involvement retrieved from the databases of Istanbul and Kocaeli Universities between 2010 and 2021. Initial OPGs of LCH cases and OPGs of healthy sex- and age-matched controls were investigated with FA. All images were assessed using ImageJ software. On each OPG, a total of 6 regions of interest (ROIs) located on the mandible were investigated bilaterally. The independent variables were the trabecular patterns of jaws of LCH cases and their control matches. The outcome variables were the fractal dimension (FD) values obtained from the ROIs on OPGs. Data were analyzed using the Mann-Whitney U test and Student's t test. Fifteen LCH-control pairs were investigated. In one ROI located in the supracortical area above the left mandibular angle, FD values of LCH cases (1.273±112.8) were significantly lower than controls (1.308±85.3; P<.05). Lower FD values were also calculated for some of the remaining ROIs, but there was no significant difference between groups (P>.05). Regarding our results, FA was not a useful parameter to discern radiographical trabecular changes between LCH cases and controls. Multicenter studies with larger populations are needed to investigate the potential of FA in the identification of this rare disease.

Vulvar Biopsy as a Key for the Diagnosis of Langerhans Cell Histiocytosis with Multifocal Involvement: Case Report and Review of Literature

Langerhans cell histiocytosis is a rare disease and due to its heterogeneous presentation represents a diagnostic and therapeutic challenge. We present the case of a patient with diabetes insipid us and panhypopituitarism, with the appearance of painful vulvar ulcers.

P1122: EFFICACY OF ALPELISIB IN PI3K-DRIVEN LANGERHANS CELL HISTIOCYTOSIS

Background: Langerhans cell histiocytosis (LCH) is an inflammatory myeloid neoplasm characterized by the accumulation of clonal dendritic cells expressing CD1a and CD207 (Langerin). LCH affects both children and adults and typically ranges from an indolent unifocal form to a progressive multisystemic disease. In the past decade, in depth molecular profiling of LCH as well as other histiocytic neoplasms demonstrated that these diseases are fundamentally dependent on somatic MAPK activating mutations, with the canonical V600E BRAF mutation emerging in more than 50% of LCH patients. Nonetheless, MAPK independent driver mutations were previously reported and anecdotal evidence of successful targeted treatment of various histiocytoses harboring non-canonical drivers such as RET, ALK and CSF1R were previously described in the literature. Aims: To report a case of PI3K driven LCH treated with an isoform specific PIK3CA inhibitor. Methods: Case summary: a 46 year-old mother of 3 presented with complaints of progressive headaches, polydipsia and polyuria. Following a pathological water deprivation test and identification of pituitary stalk thickening on MRI, a diagnosis of central diabetes insipidus (CDI) was established and desmopressin treatment was initiated. However, 10 months following her CDI diagnosis, the patient began to complain of sub febrile episodes of fever and worsening dry cough. Imaging studies including PET/CT disclosed extensive bilateral reticulo-nodular infiltration, nodules with cystic transformation and ground glass opacity, suspicious of pulmonary LCH. Histological examination of a wedge biopsy specimen obtained from the lungs confirmed the diagnosis of LCH and consequent molecular studies identified the M1043V PIK3CA mutation. During her medical investigation, the patient’s conditioned worsened, with new disease foci emerging – including cervical lymphadenopathy and a lytic vertebral lesion involving D11. The patient then received palliative radiotherapy directed at the D11 lytic lesion followed by escalating systemic therapy with single agent Alpelisib, via the Managed Access Program at Novartis. Response to treatment was assessed clinically and using PET/CT. At the molecular level, the effect of Alpelisib was assessed by measuring PTEN expression levels and cell cycle regulating non-coding RNA molecules by using quantitative real-time polymerase chain reaction (qRT-PCR). Results: Treatment with Alpelisib resulted in rapid amelioration of night sweats within 6 days, decrease in back pain within 3 weeks and normalization of all abnormally FDG avid disease foci within 3 months of treatment. The complete metabolic response observed persists currently more than a year following treatment initiation. Treatment with Alpelisib is well tolerated except for a mild increase in HbA1C levels to 6.7%. Moreover, PTEN, the main regulator of the PI3K pathway was found to be upregulated following 3 and 9 months of treatment, in parallel to downregulation of small non-coding RNAs molecules that regulates its expression. Image:Summary/Conclusion: This is the first study demonstrating that the alpha catalytic subunit of PI3K is a targetable non-canonical driver of LCH.

18F-fluorodeoxyglucose-positron emission tomography/computed tomography delineates involved sites in the cervical spine in Langerhans cell histiocytosis.

Langerhans cell histiocytosis (LCH), a granulomatous tumorous lesion consisting of CD1a-positive clonal immature dendritic cells in association with various inflammatory cells, develops in tissues including bone, skin, lungs, and lymph nodes. When bone LCH exhibits osteolytic lesions, the spine is often involved, and each part of the vertebral body, vertebral arch, and vertebral spinous process can be affected. Such vertebral LCH can occur at the onset of disease and in relapse. To confirm pathological sites, a computed tomography (CT) scan is generally used to characterize lytic lesions of vertebrae, while MRI is suitable for delineating marrow and soft tissue. Additionally, to identify specific locations, 18F-fluorodeoxyglucose-positron emission tomography/CT (FDG-PET/CT) is useful. We describe three LCH cases showing characteristic cervical spinal involvement. Case 1: A 39-year-old woman complained of right temporal pain and was found to have osteolytic lesions of right temporal/sphenoid/petrous bones. She also had central diabetes insipidus (CDI). After the diagnosis of LCH from biopsied tissue, she was treated with chemotherapy and attained remission. Four years later, she complained of neck/shoulder pain associated with herpes zoster in the right arm. PET/CT revealed a cervical spine (C3)-vertical body lesion (Figure 1A). With a revised chemotherapy regimen, she attained a second remission. Case 2: A 70-year-old man, a heavy smoker for more than 40 years, complained of shortness of breath, and a chest X-ray revealed characteristic honeycomb lungs. PET/CT showed hot lesions in the lungs, cervical spine (C3) right vertebral arch (Figure1B), and ribs. Lung lesion biopsy confirmed the diagnosis of LCH. He had no CDI and was treated with irradiation to the cervical spine and with chemotherapy. Case 3: A 40-year-old man who had severe atopic dermatitis since the age of 20 complained of nuchal pain after a traffic accident. He was also noted to have lymphadenopathy in the bilateral axillary and inguinal areas. PET/CT revealed hot signals at the spinous process of the cervical spine (C6) (Figure 1C) and lymph node lesions. Biopsy of the C6 lesion confirmed LCH. He attained a remission treated with chemotherapy and zoledronic acid. Three years later, relapse at the lymph nodes was noted, but not in the C6 lesion. He was treated with chemotherapy for refractory LCH and attained a second remission. An analysis of 76 cases of vertebral LCH by Huang et al. [1] consisted of 40 children and 36 adults, with a male to female ratio of 55:21. Lesions were predominantly in the cervical spine, followed by the thoracic and lumbosacral spines. In an analysis of 30 LCH patients with cervical spine involvement by Jiang et al. [2], 14 had atlantoaxial lesions (C1 and C2), and 16 had sub-axial (C3–C7) lesions. Chemotherapy is recommended for the management of cervical spine lesions in cases of multifocal LCH. In our three cases, two patients had spinal involvement at onset while the other developed it at relapse. All received chemotherapy because of multifocal LCH lesions. In summary, as an imaging study of cervical spine involvement in LCH, PET/CT seems to be useful for pinpointing the involved sites of vertebrae. None The authors declare no conflict of interest.

Unique Case of Congenital Langerhans Cell Histiocytosis Presenting as Intrauterine Fetal Demise

Congenital Langerhans cell histiocytosis (LCH) (formerly called Letterer–Siwe disease) is characterized by a clonal proliferation of Langerhans cells occurring in children at birth and manifests typically with multifocal cutaneous lesions, hepatosplenomegaly, lymphadenopathy, pulmonary lesions, and destructive osteolytic bone lesions. We present a case of LCH involving multiple systems high-risk organs (LCH MS-RO+), in a 32-week stillborn from a 20-year-old G2A1. The fetus was mildly hydropic and pale. Apart from maceration, the skin showed multiple targetoid lesions over the face, trunk, and limbs. There was hepatosplenomegaly and a pale brain. The placenta was large and bulky. Despite severe autolysis, histological examination showed disseminated histiocytes with multinucleated giant cells in the skin, lungs, thymus, mesenteric lymph nodes, spleen, and brain. By immunohistochemistry, the histiocytes were positive for S100, CD1a, and Langerin (CD207), confirming the diagnosis of LCH. There was extramedullary hematopoiesis in the spleen, brain, and placenta. Targeted next-generation sequencing performed on thymic DNA did not show the BRAF p.V600E variant but did show the MAP2K1 p.F53_Q58delinsL. Infants with LCH pose a diagnostic challenge due to their heterogeneous presentations. Our case is unusual in that the newborn presented with severe multiorgan involvement including brain and intrauterine death. LCH is still poorly understood requiring further genetic and molecular studies.

Langerhans Cell Histiocytosis Occurring in the Wall of a Dentigerous Cyst: Presentation of a Case

<h3>Objective</h3> The dentigerous cyst (DC) is the most common developmental odontogenic cyst. It most frequently oc- curs in association with impacted mandibular third molars. The typical radiographic presentation comprises a well-defined unliocluar radiolucency extending from the cemento-enamel junction. Yet, it is well-documented in the literature that a variety of other pathologic entities may demonstrate overlapping clinical and radiographic features. Here we present a case of Langerhans cell histiocytosis (LCH) occurring in the wall of a DC. LCH is charac- terized by infiltrates of CD1a positive cells. Disease may involve a diverse array of tissues and can be solitary or mul- tifocal. LCH occurs across the age range, yet is most commonly diagnosed in the pediatric population. BRAFV600E mutations have been identified in approximately 50% of cases tested. Here we describe the clinical, radiographic, histopathologic, immunohistochemical (IHC) and molecular findings of a case of LCH occurring in the wall of a DC. <h3>Clinical Presentation</h3> An otherwise healthy 12-year-old male presented for evaluation of an impacted right maxil- lary canine. Imaging demonstrated a 2.9 × 2.0 cm wellcircumscribed unliocluar radiolucency associated with tooth #6. <h3>Intervention and Outcome</h3> The impacted canine was extracted and the cyst enucleated under general anesthesia. Microscopic review showed a cystic lining of non-keratinized stratified squamous epithelium with an inflamed fibrovascular connective tissue wall. The inflammatory infiltrate included plasma cells, lymphocytes, numerous eosinophils, and histiocytoid cells. The histiocytoid cells stained positive for S-100 and CD1a IHC confirming the diagnosis of LCH. Analysis for BRAFV600E was negative. The patient was referred to pediatric hematology and oncology for management. <h3>Conclusion</h3> This case of LCH occurring in the wall of a DC highlights the importance of submitting all excised tissue for histopathological review. It also underscores the need for careful attention in examining the microscopic features of inflammatory infiltrates present in the walls of cystic entities.

Dermoscopic feature analysis of different skin lesions in Langerhans cell histiocytosis.

Dermoscopy was used to investigate skin lesions in 15 children with Langerhans cell histiocytosis (LCH). Purplish-red globules or patches could be seen in different rashes under dermoscopy, and histopathology showed extravasation of red blood cells. The dermoscopy findings closely correlated with the histopathology results. Purplish-red globules or patches could be useful as important dermoscopy features for the differential diagnosis of LCH.

Clinical features and difficulty in diagnosis of Langerhans cell histiocytosis in the hypothalamic-pituitary region.

Langerhans cell histiocytosis (LCH) is a multi-organ disorder that rarely involves the hypothalamic-pituitary region (HPR). HPR-LCH presents with severe progressive pituitary dysfunction and its prognosis is poor. The definitive diagnosis of LCH is considerably difficult and complicated owing to the occurrence of several diseases with similar manifestations in the HPR and its location in the deepest portion of the anterior skull base, in close proximity to important normal structures, severely limiting the size of the biopsy specimen. Chemotherapy is the established treatment modality for LCH; hence, timely and accurate diagnosis of LCH is essential for early therapeutic intervention. We retrospectively reviewed clinical features and biopsy procedures in four patients with HPR-LCH (all female, 28-44 years old) from 2009 to 2020. Maximum diameter of supra-sellar lesions was 23-35 mm and 2 cases had skip lesions. All patients demonstrated central diabetes insipidus, hyper-prolactinemia, and severe anterior pituitary dysfunction. Two of the patients had progressive disease. Furthermore, four patients presented body weight gain, two visual disturbance, and two impaired consciousness. The duration from onset to diagnosis of LCH was 3 to 10 (average 7.25) years. In total, eight operations were performed until final diagnosis. The percentage of correct diagnosis by biopsy was 50% (4/8). Clinical features of HPR-LCH are very similar to those of other HPR diseases, and their symptoms are progressive and irreversible. Clinicians should consider repeated biopsy with a more aggressive approach if the lesion is refractory to steroid therapy, in order to ensure accurate diagnosis and appropriate treatment.

Bone lesions of Langerhans cell histiocytosis triggered by trauma in children.

Bone lesions of Langerhans cell histiocytosis (LCH) may be triggered by trauma. The characteristics of pediatric patients in the JLSG-02 study cohort who developed a bone lesion at the trauma site at diagnosis of LCH were analyzed retrospectively. Of the 261 pediatric patients with LCH, 12 (4.6%), of median age 4.9 years, had trauma-triggered bone LCH lesions at diagnosis, making them significantly older than the remaining patients (P = 0.006). Trauma sites included the craniofacial regions in 10 patients and the lumbar spine and pelvis in one patient each. At the time of trauma, six patients had a bump at the site, whereas none had extradural hematomas or bone fractures. The median time from trauma to onset was 4 weeks. Of these 12 patients, three had isolated bone (IB) disease; four had multifocal bone (MFB) disease, including the bone lesion at the trauma site; and five had multisystem disease, including four with lesions in neighboring tissue and one with polyuria (posterior pituitary lesion) more than 1 year before the trauma-triggered bone lesion. Treatment responses were good in all 12 patients and none died, but relapses were observed in two patients, one each with IB and MFB disease. About 5% of pediatric patients with LCH developed new trauma-triggered bone lesions at a relatively old age. These lesions can manifest as IB, or, in patients with underlying LCH diseases, as MFB or multisystem. Good clinical outcomes were observed in these patients.

Langerhans Cell Histiocytosis without Eosinophilia and Lytic Lesions of Bone: A Rare Disease with Unusual Presentation

LCH is a disease of abnormal clonal proliferation of langerhans cell of the bone marrow derived monocyte-macrophage lineage. Cells with characteristic coffee bean / grooved / indented nuclei with a background of histiocytes, lymphocytes, eosinophils and other inflammatory cells are seen. Clinical presentation varies from unifocal unisystem to multifocal unisystem to multifocal multisystem. We present a rare case of multisystem LCH involving high risk organs in a two and a half year old child. presented with the chief complaints of fever and red raised maculopapular lesions on trunk, palm, forehead and scalp for one and a half yrs with hepatosplenomegaly. There were no lytic lesions of the bones. Hematological parameters showed anaemia with thrombocytopenia while Bone Marrow Aspirate showed increase in histiocytic cell with some cells showing characteristic coffee bean, cleaved irregularly contoured nuclei. However, eosinophilia was not seen. Sections from the skin lesions showed cells with similar morphology without usually accompanied eosinophilia. The cells were CD1a and S100 positive. So a FINAL DIAGNOSIS of langerhans cell histiocytosis was made. The emphasis here lies on thorough analysis of the clinical presentations, imaging studies and scrupulous histomorphological and immunohistochemical examination, so that early diagnosis and timely intervention is ensured in such cases where the characteristic features like lytic lesions of bone and eosinophilia is not found.

CLINICAL FEATURES AND OUTCOME IN CHILDREN WITH LANGERHANS CELL HISTIOCYTOSIS. A SINGLE INSTITUTION EXPERIENCE FROM PAKISTAN

Objective: To find out the clinical manifestations, treatment given and outcome of children with diagnosis of Langerhans cell histiocytosis.&#x0D; Study Design: Retrospective observational study.&#x0D; Place and Duration of Study: Shaukat Khanum Cancer Hospital, Lahore Pakistan, from Jan 2005 to Dec 2015.&#x0D; Methodology: Medical charts were reviewed in detail along with the available imaging for the patients. The data included age at the time of diagnosis, extent of the disease, involvement of risk organs, treatment given, response at 6th week of chemotherapy and at the end of the treatment, and outcome in terms of disease progression during the treatment, relapse of disease on follow up and cause of death either due to treatment related mortality or disease complications.&#x0D; Results: There were 29 patients, 12 patients (41%) had single system and 17 (58%) had multisystem involvement. 7 patients (41%) had risk organ involvement in the multisystem group. All the patients of multisystem and 6 patients of single system were treated according to the Langerhans cell histiocytosis III protocol. Commonest sites of involvement were bone in 22 (75%), followed by lymph nodes in 18 (62%) patients. Disease relapse was seen in 6 patients and all of them had multisystem disease. Mortality was observed only in multisystem Langerhans cell histiocytosis patients and more than 50% were risk organ positive.&#x0D; Conclusion: Langerhans cell histiocytosis is a highly heterogeneous disease. Some forms are curable without chemotherapy, while the multisystem disease requires aggressive treatment. However, despite intensive treatment, the multisystem disease and risk organs involved have poor...........

Application of 18F-FDG PET/CT in Langerhans Cell Histiocytosis.

Purpose This study aims to explore the application value of the 18F-FDG PET/CT imaging in diagnosing, staging, and typing Langerhans cell histiocytosis (LCH) via the morphological and metabolic analyses of the 18F-FDG PET/CT images. Methods We retrospectively analyzed the 18F-FDG PET/CT images and clinical data of nineteen patients with LCH. The shape, size, density, distribution, and 18F-FDG uptake of all lesions were documented. In addition, the SUVmax of the lesions, liver, and blood pool was measured prior to calculating the lesion-to-liver and lesion-to-blood pool ratios. Results Among the 19 analyzed patients, the positive rate of the PET/CT image was 94.7% (18/19), with 1 false negative (5.3%, 1/19) case occurring in the cutaneous LCH. Among the 76 lesions, 69 were FDG-avid lesions (69/76, 90.8%). Additionally, we observed no FDG uptake in 7 lesions (7/76, 9.2%). In contrast, 59 lesions (59/76, 77.6%) were abnormal on diagnostic CT scan, but 17 lesions (17/76, 22.4%) were undetected. The 18F-FDG PET/CT image revealed additional 6 lesions in the bone, 4 in the lymph node, 3 in the spleen, and 3 occult lesions, which CT scan did not detect. Additionally, there were 6 cases with single-system LCH. The remaining 13 cases were multisystem LCH. Our 18F-FDG PET/CT image analyses altered the typing of 4 LCH patients. In the case of all lesions, the mean SUVmax of the 18F-FDG-avid lesions was 5.4 ± 5.1 (range, 0.8∼26.2), and the mean lesion-to-liver SUVmax ratio was 3.1 ± 2.52 (range, 0.7∼11.9), and the mean lesion-to-blood pool SUVmax ratio was 4.6 ± 3.4 (range 0.7∼17.5). Conclusion The 18F-FDG PET/CT image plays an essential role in LCH diagnosis, primary staging, and typing. It can accurately evaluate the distribution, range, and metabolic information of LCH, providing a vital imaging basis for the clinical evaluation of disease conditions, selection of treatment schemes, and determining patient prognosis.

Orbital presentation of Langerhans cell histiocytosis

AbstractPurposeTo analyze and review an ophthalmic manifestation of an uncommon pathology such as Langerhans cell histiocytosis (LCH).MethodsSingle‐patient case report.ResultsLCH is an uncommon disorder produced by mononuclear phagocyte system cell proliferation, resulting in antigen‐presenting cells similar to Langerhans cells invading bone, skin, bone marrow, lymphatic nodes, liver, spleen and central nervous system (CNS). The number and location of affected organs is key in treatment and prognosis. In this case report, a 16‐year‐old girl presented 10 day‐long superoexternal orbital pain associated with palpebral edema, making acute dacryoadenitis and preseptal cellulitis the most common differential diagnoses. After poor response to antibiotic and anti‐inflamatory oral treatment, CT scan was ordered, showing an osteolytic frontal mass at the superoexternal orbital roof, expanding to extraconal space and anterior cranial fossa. With a differential diagnosis of LCH, osteomyelitis, hematologic disease or vascular malformation, among others, a biopsy was performed, confirming the LCH diagnosis. An extension exam was performed, excluding new tumors, reaching a diagnosis of a monostotic bone form of LCH. Chemotherapy with prednisone and visblastine was advised due CNS affectation risk because of the tumor’s location, with evident but incomplete response after six‐week induction and complete response after a second six‐week induction cycle. The patient is currently ongoing consolidation chemotherapy.ConclusionsOrbital tumors are not frequent in pediatric ages, but they must be included in the differential diagnosis of orbital cellulitis, since that can be the first manifestation of these tumors.

Langerhans Cell Histiocytosis: A Case Report

Langerhans cell histiocytosis is a rare disease characterized by clonal proliferation of dendritic cells. Diagnosis can be difficult due to heterogeneity of clinical manifestations, affecting several organs and/or systems. We report the case of a 9-month-year-old boy who is referenced to our center due to anemia and iron deficiency. The clinical presentation with exuberant skin manifestations and persistent/recurrent infections raised the suspicion of Langerhans cell histiocytosis, confirmed with positive immunoreactivity of bone marrow cells for CD1a and protein S100. We highlight the importance of detailed clinical history in the diagnosis of Langerhans cell histiocytosis and the importance of an early diagnosis.

Adult Langerhans cell histiocytosis involving adjacent vertebra on 18F-FDG PET/CT imaging.

Langerhans cell histiocytosis (LCH) of the spine involving the intervertebral disk and adjacent vertebra is rare in adults. We report a case of a 56-year-old woman with neck pain and right upper limbs numbness. Fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) showed an osteolytic bone lesion in the fourth cervical vertebra (C4) with soft-tissue mass, invading the adjacent intervertebral disc and posterior vertebral body of C3, compressing dural sac and cervical spinal cord. The lesion showed increased 18F-FDG uptake with a maximum standardized uptake value (SUVmax) of 6.75. Subsequently, the histopathologic examination confirmed the diagnosis of LCH.

Incidental finding of Langerhans cell histiocytosis of temporoparietal bone - A case report.

Introduction and importanceLangerhans cell histiocytosis (LCH) is a rare haematological disorder affecting infants and young children and has an estimated incidence of 2-5 cases per million people per year. LCH invades the reticuloendothelial system and causes the proliferation of Langerhans cells and mature eosinophils. LCH involving the temporoparietal bone has rarely been reported in the literature.Presentation of caseA ten-year-old boy presented to the Neurosurgical outpatient clinic with a swelling on the right temporoparietal region following a fall from his bicycle. Local examination revealed a single, 3 × 3 cm, non-tender, cystic, immobile swelling in the right temporoparietal region. On evaluation for recent head trauma, an incidental finding of eosinophilic granuloma was discovered on a CT scan. The FNAC was suggestive of a histiocytic lesion pertaining to a diagnosis of LCH. The patient underwent wide excision of the mass and cranioplasty. A one-month follow-up CT scan of the head had no evidence of residual or recurrent disease.DiscussionEosinophilic granuloma is one of the three variants of LCH and has a relatively better prognosis. Clinical diagnosis can be challenging and mandates tissue sampling for histopathological examination. Treatment modalities including surgery, radiotherapy, chemotherapy, and steroid injection are used alone, or in combination, depending on the extent and severity of the disease.ConclusionExamining a swelling in the temporoparietal region with no other characteristic symptoms could be a case of LCH. The timely diagnosis and surgical excision with other adjuvant treatment options of this rare pediatric disease would help in a better outcome.

Multisystem Langerhans Cell Histiocytosis in high-risk group: A case series of two infants

Background:&nbsp; Langerhans Cell Histiocytosis (LCH) has diverse manifestations, from asymptomatic to aggressive, which involves many organs. Histopathological examination play s a&nbsp; crucial role as&nbsp; a&nbsp; basic diagnostic standard for LCH. Writing Group of the Histiocyte Society proposes a guideline for diagnosing LCH, divided into presumptive, designated, and definitive diagnosis.&nbsp; Case Illustration: Two cases of a 14 month-old girl and an 18 month-old girl presented similar clinical manifestation and multi - organ involvement. Dermatological examination revealed red papules and plaques covered by brownish scales and crusts on the scalp and body, erosion in some folds of the body. Histopathological examination of the first case revealed&nbsp; an&nbsp; early purpuric phase. S100 immunostaining just revealed hyperplasia of Langerhans cell but still could not support the diagnosis of LCH.&nbsp; Fine Needle Aspiration Biopsy of the enlarged submandibular lymph node after two months&nbsp; of observation suggested LCH.&nbsp; In the second case, histopathological examination revealed proliferation of round-oval nucleated cells, pleomorphic, some reniform nuclei, with amphophilic cytoplasm. S100 and CD1a immunostaining revealed a positive reaction in the proliferative cell s. Discussion: Patients aged 14 and 18 months old indicated almost similar clinical manifestations leading to LCH diagnosis, with different histopathological pictures. The first patient was presumptively diagnosedas high - risk multisystem LCH, but theinitial histopathology results did not support LCH diagnosis. On the other hand, the second patient was definitively diagnosed with high-risk multisystem LCH.&nbsp; Conclusion: Patient s with clinically suspected LCH without histopathological confirmation should be observed at least six months to reassess the necessity of a follow - up biopsy. &nbsp; Keywords :&nbsp; Langerhans Cell Histiocytosis, multisystem organ, histopathology, S100