In the basal ganglia, MRI shows a hyperintense T1 signal in the globus pallidus.Assessment of endocrine function and bonemarrow biopsy are also performed when indicated. S-100 protein is expressed in a cytoplasmic pattern
peanut agglutinin (PNA) is expressed on the cell surface and perinuclearly
major histocompatibility (MHC) class II is expressed (because histiocytes are macrophages)
CD1a
langerin (CD207), a Langerhans Cell–restricted protein that induces the formation of Birbeck granules and is constitutively associated with them, is a highly specific marker. Treatment
Guidelines for management of patients up to 18 years with Langerhans cell histiocytosis have been suggested. Treatment is guided by extent of disease. Solitary bone lesion may be amenable through excision or limited radiation, dosage of 5-10 Gy for children, 24-30 Gy for adults. However systemic diseases often require chemotherapy. Use of systemic steroid is common, singly or adjunct to chemotherapy. Local steroid cream is applied to skin lesions. Endocrine deficiency often require lifelong supplement e.g. desmopressin for diabetes insipidus which can be applied as nasal drop. Chemotherapeutic agents such as alkylating agents, antimetabolites, vinca alkaloids either singly or in combination can lead to complete remission in diffuse disease. Prognosis
Excellent for single-focus disease. With multi-focal disease 60% have a chronic course, 30% achieve remission and mortality is up to 10%. Prevalence
LCH usually affects children between 1 and 15 years old, with a peak incidence between 5 and 10 years of age. Among children under the age of 10, yearly incidence is thought to be 1 in 200,000; and in adults even rarer, in about 1 in 560,000.
It can appear as a single lesion in an organ, up to a large quantity of lesions in one organ. When multiple lesions are scattered throughout an organ, it can be called a multifocal unisystem variety. When found in the lungs, it should be distinguished from Pulmonary Langerhans cell hystiocytosis—a special category of disease most commonly seen in adult smokers. When found in the skin it is called cutaneous single system Langerhans cell LCH. This version can heal without therapy in some rare cases. This primary bone involvement helps to differentiate eosinophilic granuloma from other forms of Langerhans Cell Histiocytosis (Letterer-Siwe or Hand-Schüller-Christian variant). Multifocal unisystem
Seen mostly in children, multifocal unisystem LCH is characterized by fever, bone lesions and diffuse eruptions, usually on the scalp and in the ear canals. 50% of cases involve the pituitary stalk, often leading to diabetes insipidus. The triad of diabetes insipidus, exophthalmos, and lytic bone lesions is known as the Hand-Schüller-Christian triad. Peak onset is 2–10 years of age. Multifocal multisystem
Multifocal multisystem LCH, also called Letterer-Siwe disease, is an often rapidly progressing disease in which Langerhans Cell cells proliferate in many tissues. It is mostly seen in children under age 2, and the prognosis is poor: even with aggressive chemotherapy, the five-year survival is only 50%. Pulmonary Langerhans cell histiocytosis (PLCH)
Pulmonary Langerhans cell histiocytosis (PLCH) is a unique form of LCH in that it occurs almost exclusively in cigarette smokers. It is now considered a form of smoking-related interstitial lung disease.