title: Immunocytochemical investigation of Langerin (CD207) is a valuable adjunct in the cytological diagnosis of Langerhans cell histiocytosis of the thyroid.
abstract: Langerhans cell histiocytosis (LCH) is an uncommon disease encompassing three clinically different entities: eosinophilic granuloma, Hand-Schüller-Christian disease, and Abt-Letterer-Siewe disease. Despite usually being a multisystemic disease affecting numerous different organs, involvement of the thyroid gland is extremely rare, and only a few cases in adults have been described in the literature. Herein, we present the case of a 28-year-old male patient presenting with LCH involving the skin, the skeletal system, and the thyroid gland. Fine needle aspiration (FNA) of the thyroid was performed and showed the typical Langerhans cells (LC) with foamy cytoplasm and slender nuclei with longitudinal grooves against a background of inflammatory cells with only a few eosinophilic granulocytes. Immunocytochemically, the LC showed positive staining with antibodies against CD1a and Langerin, a recently detected glycoprotein exclusively expressed in LC. Langerin is the major protein that makes up the so-called Birbeck granules, the electronmicroscopical hallmark of LC. Since LCH involvement of the thyroid is occasionally mistaken for papillary thyroid carcinoma cells, we propose that application of Langerin in combination with CD1a is a helpful diagnostic adjunct for the correct assessment of LCH affecting the thyroid gland.
authors.affiliation: Department of Pathology and Neuropathology, University Hospital of Essen, University of Duisburg-Essen, Hufelandstrasse 55, 45147 Essen, Germany. jeremias.wohlschlaeger@uk-essen.de
authors.forename: Jeremias
authors.initials: J
authors.lastname: Wohlschlaeger
authors.forename: Silke
authors.initials: S
authors.lastname: Ebert
authors.forename: Sien-Yi
authors.initials: SY
authors.lastname: Sheu
authors.forename: Kurt Werner
authors.initials: KW
authors.lastname: Schmid
authors.forename: Martin
authors.initials: M
authors.lastname: Totsch
mesh_terms: D000328:Adult; D015703:Antigens, CD / Q000378:metabolism*; D044963:Biopsy, Fine-Needle; D001847:Bone Diseases / Q000175:diagnosis / Q000378:metabolism; D003584:Cytological Techniques; D006646:Histiocytosis, Langerhans-Cell / Q000175:diagnosis* / Q000378:metabolism / Q000503:physiopathology; D006801:Humans; D007150:Immunohistochemistry; D037181:Lectins, C-Type / Q000378:metabolism*; D008297:Male; D037241:Mannose-Binding Lectins / Q000378:metabolism*; D012871:Skin Diseases / Q000175:diagnosis / Q000378:metabolism; D013959:Thyroid Diseases / Q000175:diagnosis* / Q000378:metabolism / Q000601:surgery
chemical_list: D015703:Antigens, CD; C121916:CD207 protein, human; D037181:Lectins, C-Type; D037241:Mannose-Binding Lectins