Diagnosis of nodal Langerhans cell histiocytosis by fine needle aspiration cytology.

Langerhans cell histiocytosis (LCH) is a rare disease and disease confined to the lymph nodes is even more uncommon. Fine needle aspiration (FNA) cytology of LCH of the lymph nodes has rarely been described. A case study of LCH of the lymph nodes in a 23-year-old man is presented. FNA smears showed high cellularity composed of many isolated Langerhans cells (LCs) with nuclear grooves admixed with numerous eosinophils, lymphocytes, giant cells, macrophages, and neutrophils. Further immunohistochemical study of the excised lymph node sections revealed that the histiocytes were positively stained with CD1a. The presence of LCs with nuclear grooves and eosinophils suggests the possibility of LCH. FNA cytology is a valuable method for diagnosis.