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Nature Reviews. Disease Primers Oct 2021The historic term 'histiocytosis' meaning 'tissue cell' is used as a unifying concept for diseases characterized by pathogenic myeloid cells that share histological... (Review)
Review
The historic term 'histiocytosis' meaning 'tissue cell' is used as a unifying concept for diseases characterized by pathogenic myeloid cells that share histological features with macrophages or dendritic cells. These cells may arise from the embryonic yolk sac, fetal liver or postnatal bone marrow. Prior classification schemes align disease designation with terminal phenotype: for example, Langerhans cell histiocytosis (LCH) shares CD207 antigen with physiological epidermal Langerhans cells. LCH, Erdheim-Chester disease (ECD), juvenile xanthogranuloma (JXG) and Rosai-Dorfman disease (RDD) are all characterized by pathological ERK activation driven by activating somatic mutations in MAPK pathway genes. The title of this Primer (Histiocytic disorders) was chosen to differentiate the above diseases from Langerhans cell sarcoma and malignant histiocytosis, which are hyperproliferative lesions typical of cancer. By comparison LCH, ECD, RDD and JXG share some features of malignant cells including activating MAPK pathway mutations, but are not hyperproliferative. 'Inflammatory myeloproliferative neoplasm' may be a more precise nomenclature. By contrast, haemophagocytic lymphohistiocytosis is associated with macrophage activation and extreme inflammation, and represents a syndrome of immune dysregulation. These diseases affect children and adults in varying proportions depending on which of the entities is involved.
Topics: Erdheim-Chester Disease; Histiocytosis, Langerhans-Cell; Histiocytosis, Sinus; Humans; Inflammation; Xanthogranuloma, Juvenile
PubMed: 34620874
DOI: 10.1038/s41572-021-00307-9 -
La Clinica Terapeutica 2020To better understand the real prevalence of cutaneous manifestations, in Neurofibromatosis type 1. (Review)
Review
OBJECTIVE
To better understand the real prevalence of cutaneous manifestations, in Neurofibromatosis type 1.
MATERIALS AND METHODS
We reviewed all clinical charts of 1102 NF1 patients followed by February 1983 to February 2020 at the "Sapienza" University of Rome, Italy. NF1 patients are seen usually every year by a dermatologist.
RESULT
Café-au-lait macules were shown in 1063 patients (96.5%), axillary and inguinal freckling in 991 (90%) and neurofibromas in 861 (78.1%). Other skin manifestations included: lipoma (6.2%), nevus anemicus (3.9%), psoriasis (3.4%), spilus nevus (3.2%), juvenile xanthogranuloma (3.2%), vitiligo (2.3%), Becker's nevus (1.9%), melanoma (0.7%) and poliosis (0.5%).
CONCLUSION
Neurofibromatosis type 1 is a multisystem disorder primarily involving the skin and nervous system. The clinical manifestations are extremely variable even within a family. This study was performed to delineate the prevalence of cutaneous manifestations in NF1.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Child; Child, Preschool; Female; Humans; Italy; Male; Middle Aged; Neurofibromatosis 1; Prevalence; Skin Diseases; Young Adult
PubMed: 32901776
DOI: 10.7417/CT.2020.2242 -
Actas Dermo-sifiliograficas Nov 2020Juvenile xanthogranulomas (JXGs) are rare, benign lesions that belong to the large group of non-Langerhans cell histiocytoses. JXG presents with 1 or more erythematous... (Review)
Review
Juvenile xanthogranulomas (JXGs) are rare, benign lesions that belong to the large group of non-Langerhans cell histiocytoses. JXG presents with 1 or more erythematous or yellowish nodules that are usually located on the head or neck. Most JXG lesions are congenital or appear during the first year of life. Extracutaneous involvement is rare, but the literature traditionally suggests investigating the possibility of ocular compromise. JXG is mainly a clinical diagnosis, but a skin biopsy may sometimes be needed for confirmation. JXGs on the skin are self-limiting and usually do not require treatment. This review describes the clinical and therapeutic aspects of JXG, emphasizing available evidence and the diagnosis of extracutaneous involvement.
Topics: Biopsy; Histiocytosis, Non-Langerhans-Cell; Humans; Skin; Xanthogranuloma, Juvenile
PubMed: 32721389
DOI: 10.1016/j.ad.2020.07.004 -
Hematological Oncology Jun 2021Children with Langerhnans cell histiocytosis (LCH) develop granulomatous lesions with characteristic clonal CD207+ dendritic cells that can arise as single lesions or... (Review)
Review
Children with Langerhnans cell histiocytosis (LCH) develop granulomatous lesions with characteristic clonal CD207+ dendritic cells that can arise as single lesions or life-threatening disseminated disease. Despite the wide range of clinical presentations, LCH lesions are histologically indistinguishable based on severity of disease, and uncertain classification as an immune versus neoplastic disorder has historically challenged the development of optimal clinical strategies for patients with LCH. Recently, activating somatic mutations in MAPK pathway genes, most notably BRAFV600E, have been discovered in almost all cases of LCH. Further, the stage of myeloid differentiation in which the mutation arises defines the extent of disease and risk of developing LCH-associated neurodegeneration. MAPK activation in LCH precursor cells drives myeloid differentiation, inhibits migration, and inhibits apoptosis, resulting in accumulation of resilient pathologic dendritic cells that recruit and activate T cells. Recurrent somatic mutations in MAPK pathway genes have also been identified in related histiocytic disorders: juvenile xanthogranuloma, Erdheim-Chester disease, and Rosai-Dorfman disease. New insights into pathogenesis support reclassification of these conditions as a myeloid neoplastic disorders. Continued research will uncover opportunities to identify novel targets and inform personalized therapeutic strategies based on cell of origin, somatic mutation, inherited risk factors, and residual disease.
Topics: Amino Acid Substitution; Cell Differentiation; Cell Movement; Dendritic Cells; Histiocytosis, Langerhans-Cell; Humans; MAP Kinase Signaling System; Mutation, Missense; Precision Medicine; Proto-Oncogene Proteins B-raf; T-Lymphocytes
PubMed: 34105821
DOI: 10.1002/hon.2857 -
Cancers Jan 2021Neurofibromatosis type 1 (NF1) is a complex autosomal dominant disorder associated with germline mutations in the NF1 tumor suppressor gene. NF1 belongs to a class of... (Review)
Review
Neurofibromatosis type 1 (NF1) is a complex autosomal dominant disorder associated with germline mutations in the NF1 tumor suppressor gene. NF1 belongs to a class of congenital anomaly syndromes called RASopathies, a group of rare genetic conditions caused by mutations in the Ras/mitogen-activated protein kinase pathway. Generally, NF1 patients present with dermatologic manifestations. In this review the main features of café-au-lait macules, freckling, neurofibromas, juvenile xanthogranuloma, nevus anemicus and other cutaneous findings will be discussed.
PubMed: 33530415
DOI: 10.3390/cancers13030463 -
Indian Pediatrics Nov 2018
Topics: Child, Preschool; Diagnosis, Differential; Exanthema; Humans; Male; Skin; Xanthogranuloma, Juvenile
PubMed: 30587663
DOI: No ID Found -
AJNR. American Journal of Neuroradiology Nov 2022Juvenile xanthogranuloma is a rare clonal, myeloid, neoplastic disorder. Typically, juvenile xanthogranuloma is a self-limited disorder of infancy, often presenting as a...
BACKGROUND AND PURPOSE
Juvenile xanthogranuloma is a rare clonal, myeloid, neoplastic disorder. Typically, juvenile xanthogranuloma is a self-limited disorder of infancy, often presenting as a solitary red-brown or yellow skin papule/nodule. A small subset of patients present with extracutaneous, systemic juvenile xanthogranuloma, which may include the CNS. The goal of this retrospective study was to evaluate and categorize the neuroimaging findings in a representative cohort of pediatric patients with CNS juvenile xanthogranuloma.
MATERIALS AND METHODS
The brain and/or spine MR imaging data of 14 pediatric patients with pathology-proven juvenile xanthogranuloma were categorized and evaluated for the location; the signal intensity of xanthogranulomas on T1WI, T2WI, DWI, and a matching ADC map for the pattern and degree of contrast enhancement; and the presence of perilesional edema, cysts, or necrosis.
RESULTS
Fourteen pediatric patients (8 girls, 6 boys; mean age, 84 months) were included in the study. Patients presented with a wide variety of different symptoms, including headache, seizure, ataxia, strabismus, hearing loss, facial paresis, and diabetes insipidus. Juvenile xanthogranuloma lesions were identified in a number of different sites, including supra- and infratentorial as well as intracranial and spinal leptomeningeal. Five patients were categorized into the neuroradiologic pattern unifocal CNS juvenile xanthogranuloma; 8, into multifocal CNS juvenile xanthogranuloma; and 1, into multifocal CNS juvenile xanthogranuloma with intracranial and spinal leptomeningeal disease. In most cases, xanthogranulomas were small-to-medium intra-axial masses with isointense signal on T1WI (compared with cortical GM), iso- or hyperintense signal on T2WI, had restricted diffusion and perilesional edema. Almost all xanthogranulomas showed avid contrast enhancement. However, we also identified less common patterns with large lesions, nonenhancing lesions, or leptomeningeal disease. Four cases had an additional CT available. On CT, all xanthogranulomas were homogeneously hyperdense (solid component) without evident calcifications.
CONCLUSIONS
CNS juvenile xanthogranuloma may demonstrate heterogeneous neuroimaging appearances potentially mimicking other diseases, such as primary brain neoplasms, metastatic disease, lymphoma and leukemia, other histiocytic disorders, infections, or granulomatous diseases.
Topics: Male; Female; Child; Humans; Xanthogranuloma, Juvenile; Retrospective Studies; Magnetic Resonance Imaging; Neuroimaging; Head
PubMed: 36265894
DOI: 10.3174/ajnr.A7683 -
Postepy Dermatologii I Alergologii Jun 2019
PubMed: 31333355
DOI: 10.5114/ada.2019.85643 -
American Journal of Medical Genetics.... Oct 2021Noonan syndrome (NS) is one of the common RASopathies. While the clinical phenotype in NS is variable, it is typically characterized by distinctive craniofacial...
Noonan syndrome (NS) is one of the common RASopathies. While the clinical phenotype in NS is variable, it is typically characterized by distinctive craniofacial features, cardiac defects, reduced growth, bleeding disorders, learning issues, and an increased risk of cancer. Several different genes cause NS, all of which are involved in the Ras/mitogen-activated protein kinase (Ras/MAPK) pathway. Juvenile xanthogranuloma (JXG) is an uncommon, proliferative, self-limited cutaneous disorder that affects young individuals and may be overlooked or misdiagnosed due to its transient nature. A RASopathy that is known to be associated with JXG is neurofibromatosis type 1 (NF1). JXG in NF1 has also been reported in association with a juvenile myelomonocytic leukemia (JMML). As RASopathies, both NS and NF1 have an increased incidence of JMML. We report a 10-month-old female with NS who has a PTPN11 pathogenic variant resulting in a heterozygous SHP2 p.Y62D missense mutation. She was found to have numerous, small, yellow-pink smooth papules that were histopathologically confirmed to be JXG. In understanding the common underlying pathogenetic dysregulation of the Ras/MAPK pathway in both NS and NF1, this report suggests a possible molecular association for why NS individuals may be predisposed to JXG.
Topics: Female; Genetic Predisposition to Disease; Humans; Infant; Leukemia, Myelomonocytic, Juvenile; Mutation, Missense; Neurofibromin 1; Noonan Syndrome; Phenotype; Protein Tyrosine Phosphatase, Non-Receptor Type 11; Xanthogranuloma, Juvenile; ras Proteins
PubMed: 34032360
DOI: 10.1002/ajmg.a.62353