{"id":4422296,"date":"2025-01-11T12:38:54","date_gmt":"2025-01-11T18:38:54","guid":{"rendered":"https:\/\/myendoconsult.com\/learn\/topics\/langerhans-cell-histiocytosis\/"},"modified":"2025-01-13T06:49:02","modified_gmt":"2025-01-13T12:49:02","slug":"langerhans-cell-histiocytosis","status":"publish","type":"oen_topic","link":"https:\/\/myendoconsult.com\/learn\/topics\/langerhans-cell-histiocytosis\/","title":{"rendered":"Langerhans Cell Histiocytosis"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\">LANGERHANS CELL HISTIOCYTOSIS (LCH) IN CHILDREN<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Definition and Pathophysiology<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Langerhans Cell Histiocytosis (LCH)<\/strong>:\n<ul class=\"wp-block-list\">\n<li>A disorder of <strong>Langerhans cells<\/strong>, which are bone marrow\u2013derived dendritic cells involved in antigen processing.<\/li>\n\n\n\n<li>In LCH, these cells lose the ability to present antigens, leading to immunologic dysfunction.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Normal Langerhans Cells<\/strong>: Found in the epidermis, lymph nodes, thymic epithelium, and bronchial mucosa.\n<ul class=\"wp-block-list\">\n<li>Migrate to lymphoid tissues and stimulate T-cell responses.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Incidence<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Rarity<\/strong>: Affects approximately <strong>3\u20135 children per million<\/strong> each year.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Clinical Presentations<\/h3>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Localized Disease<\/strong>\n<ul class=\"wp-block-list\">\n<li>Common presenting sites include <strong>bone, skin, or lymph nodes<\/strong>.<\/li>\n\n\n\n<li><strong>Skin involvement in infants<\/strong>: Brown-purplish papules, often benign and self-healing in the first year of life.<\/li>\n\n\n\n<li>Later in infancy: Red papular rash on neck, axilla, abdomen, back, groin, and scalp.<\/li>\n\n\n\n<li>When skin-limited LCH is suspected, additional workup (CT of chest and abdomen, bone marrow biopsy) is warranted to rule out multisystem involvement.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Multisystem Disease<\/strong>\n<ul class=\"wp-block-list\">\n<li>May present later in childhood with more extensive involvement (e.g., liver, spleen, bone marrow).<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n<h3 class=\"wp-block-heading\">Bone Involvement<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Most Common Site<\/strong>: Skull (lytic lesions causing localized pain, swelling, and sometimes erythema).<\/li>\n\n\n\n<li>Other bones: Ribs, cervical vertebral bodies, humerus, femur.<\/li>\n\n\n\n<li><strong>Mass-Effect Presentations<\/strong>:\n<ul class=\"wp-block-list\">\n<li>Skull base, maxillofacial bone, or sellar involvement \u2192 hearing loss, exophthalmos, <a href=\"https:\/\/myendoconsult.com\/learn\/mnemonic-cranial-nerves-dirty-surprise\/\"  data-wpil-monitor-id=\"77\">cranial nerve<\/a> palsies, diabetes insipidus (DI).<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Skull Radiographs<\/strong>: May show irregular \u201cgeographic skull\u201d lesions.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Endocrine Manifestations<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong><a href=\"https:\/\/myendoconsult.com\/learn\/triphasic-response-of-diabetes-insipidus\/\"  data-wpil-monitor-id=\"79\">Diabetes Insipidus<\/a> (DI)<\/strong>:\n<ul class=\"wp-block-list\">\n<li>Most common endocrine manifestation.<\/li>\n\n\n\n<li>Can be the initial presenting symptom.<\/li>\n\n\n\n<li>Often associated with anterior pituitary insufficiency and thickening of the <a href=\"https:\/\/myendoconsult.com\/learn\/pituitary-stalk-thickening\/\"  data-wpil-monitor-id=\"80\">pituitary stalk<\/a> on imaging.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Lymph Node Involvement<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Isolated Lymphadenopathy<\/strong>:\n<ul class=\"wp-block-list\">\n<li>Usually in the cervical or mediastinal lymph nodes.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Diffuse Multisystem Disease<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Liver and Spleen<\/strong>:\n<ul class=\"wp-block-list\">\n<li>Clotting factor deficiencies, increased bilirubin, low albumin (liver involvement).<\/li>\n\n\n\n<li>Splenomegaly can cause cytopenias.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Lung Involvement<\/strong>:\n<ul class=\"wp-block-list\">\n<li>Cystic and nodular pattern on imaging.<\/li>\n\n\n\n<li>Pneumothorax may be an initial sign.<\/li>\n\n\n\n<li>Can lead to diffuse fibrosis, resulting in dyspnea.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Bone Marrow<\/strong>: Commonly affected in diffuse disease.<\/li>\n\n\n\n<li><strong>Central Nervous System<\/strong>: Ataxia, cognitive dysfunction if the cerebellum or basal ganglia are involved.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Historical Terminology<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Hand-Sch\u00fcller-Christian disease<\/strong>: LCH with prominent skull defects, DI, exophthalmos.<\/li>\n\n\n\n<li><strong>Letterer-Siwe disease<\/strong>: LCH with extensive multiorgan involvement.<\/li>\n\n\n\n<li><strong>Eosinophilic Granuloma<\/strong>: Localized lesion(s) confined to bone.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">LANGERHANS CELL HISTIOCYTOSIS (LCH) IN ADULTS<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Definition and Pathophysiology<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Same overall mechanism as in children: LCH is a disorder of <strong>bone marrow\u2013derived Langerhans cells<\/strong> that lose their antigen-presenting ability.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Incidence and Demographics<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Rarity<\/strong>: Affects about <strong>1\u20132 persons per million<\/strong> each year.<\/li>\n\n\n\n<li><strong>Mean Age at Diagnosis<\/strong>: ~32 years.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Clinical Presentation<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Common Symptoms<\/strong> (in approximate order of frequency):\n<ol class=\"wp-block-list\">\n<li><strong>Dermatologic<\/strong> (rash)<\/li>\n\n\n\n<li><strong>Pulmonary<\/strong> (cough, dyspnea, tachypnea)<\/li>\n\n\n\n<li><strong>Bone Pain<\/strong><\/li>\n\n\n\n<li><strong>Diabetes Insipidus (DI)<\/strong> (~25% of adult patients)<\/li>\n\n\n\n<li><strong>Systemic<\/strong> (fever, weight loss)<\/li>\n\n\n\n<li><strong>Lymphadenopathy<\/strong><\/li>\n\n\n\n<li><strong>Ataxia<\/strong><\/li>\n\n\n\n<li><strong>Gingival Hypertrophy<\/strong><\/li>\n<\/ol>\n<\/li>\n\n\n\n<li><strong>Skin Lesions<\/strong>: Papular, pigmented (red, brown), possibly ulcerating in intertriginous areas.<\/li>\n\n\n\n<li><strong>Bone Involvement<\/strong>:\n<ul class=\"wp-block-list\">\n<li>Common sites: Mandible, skull, long bones, pelvis, scapula, vertebral bodies, ribs.<\/li>\n\n\n\n<li>Jaw pain and \u201cfloating teeth\u201d on dental radiographs if the mandible is involved.<\/li>\n\n\n\n<li>Lytic lesions with a beveled edge on radiographs.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Pulmonary LCH<\/strong>:\n<ul class=\"wp-block-list\">\n<li>May present with pneumothorax.<\/li>\n\n\n\n<li>Exacerbated by cigarette smoking.<\/li>\n\n\n\n<li>Imaging: Diffuse honeycomb lung appearance on chest radiographs; CT shows typical nodules and cysts.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Endocrine<\/strong>:\n<ul class=\"wp-block-list\">\n<li><strong><a href=\"https:\/\/myendoconsult.com\/learn\/topics\/diabetes-insipidus\/\"  data-wpil-monitor-id=\"78\">Diabetes Insipidus<\/a><\/strong> is irreversible in many adult LCH cases due to infiltrative damage to the hypothalamus and pituitary stalk.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Diagnosis<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Biopsy of Lesion<\/strong>:\n<ul class=\"wp-block-list\">\n<li>Mixed cellular infiltrate with immature clonal Langerhans cells (positive for S100, vimentin, CD1a, antilangerin).<\/li>\n\n\n\n<li>Eosinophils, macrophages, granulocytes, lymphocytes often present.<\/li>\n\n\n\n<li>Multinucleated giant cells (foam cells) may appear with accumulated cholesterol.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Full Laboratory and Imaging Workup<\/strong>:\n<ul class=\"wp-block-list\">\n<li>CBC, liver function tests, coagulation studies, fasting urine\/serum osmolality.<\/li>\n\n\n\n<li>Imaging: Skeletal survey, skull radiographs, chest radiograph, possibly head MRI, chest CT, pulmonary function tests, bone marrow biopsy depending on symptoms.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Prognosis<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Influenced by:\n<ol class=\"wp-block-list\">\n<li><strong>Age of Onset<\/strong> (better if older than 2 years)<\/li>\n\n\n\n<li><strong>Number of Organs Involved<\/strong><\/li>\n\n\n\n<li><strong>Degree of Organ Dysfunction<\/strong> (e.g., hyperbilirubinemia)<\/li>\n<\/ol>\n<\/li>\n\n\n\n<li>An adult with a single bone lesion may have an excellent outlook, whereas an infant with extensive multiorgan disease has a worse prognosis.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Treatment<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Stratification by Prognosis<\/strong>:\n<ul class=\"wp-block-list\">\n<li><strong>Chemotherapeutic Agents<\/strong>: Cladribine (2-chlorodeoxyadenosine), vinblastine, etoposide, methotrexate, 6-mercaptopurine.<\/li>\n\n\n\n<li><strong>Corticosteroids<\/strong>: Topical or systemic.<\/li>\n\n\n\n<li><strong>Radiotherapy<\/strong> (localized) and <strong>Surgical Curettage<\/strong> for solitary bone lesions.<\/li>\n\n\n\n<li><strong>Anticytokine Therapies<\/strong>: Under investigation.<\/li>\n\n\n\n<li><strong>Bone Marrow Transplantation<\/strong>: In refractory cases.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>LANGERHANS CELL HISTIOCYTOSIS (LCH) IN CHILDREN Definition and Pathophysiology Incidence Clinical Presentations Bone Involvement Endocrine Manifestations Lymph Node Involvement Diffuse Multisystem Disease Historical Terminology&hellip;<\/p>\n","protected":false},"featured_media":0,"template":"","oen_topic_chapter":[682],"class_list":["post-4422296","oen_topic","type-oen_topic","status-publish","hentry","oen_topic_chapter-pituitary-gland"],"_links":{"self":[{"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic\/4422296","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic"}],"about":[{"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/types\/oen_topic"}],"version-history":[{"count":3,"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic\/4422296\/revisions"}],"predecessor-version":[{"id":4422300,"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic\/4422296\/revisions\/4422300"}],"wp:attachment":[{"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/media?parent=4422296"}],"wp:term":[{"taxonomy":"oen_topic_chapter","embeddable":true,"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic_chapter?post=4422296"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}