ABSTRACT
The terms Langerhans' cell histiocytosis, histiocytosis x, Langerhans' cell granulomatosis and eosinophilic granuloma are used for a specific but variable clinico-pathology entity that are presented by proliferation of Langerhans' cell accompanied by a variable number of eosinophils, giant cells and neutrophils. Langerhans' cells usually have characteristic nuclei. The nuclei are often elongated, lobulated with prominent grooves and folds. The Cytoplasm is acidophilic and abundant. Most Langerhans' cells are mononuclear but occasionally they have several nuclei. On electron microscopic examination the Langerhans' cell shows specific intracytoplasmic organelles [Bubeck's granules]. For years this method has been used for identifying the Langerhans' cell. Today immunohistochemistry stain is a reliable method for definite diagnosis. According to Histiocyte Society even a typical clinical and light microscopic picture must be confirmed by a positive S100 or CD a immunohistochemistry stains