Which of the following is not a type of langerhans cell histiocytosis?
High-Yield Explanation
Ans. is `d.' i.e., Torres syndrome Langerhans cell histiocvtosis (Histiocytosis X) Histiocytosis X is characterized by proliferation of Langerhans histiocytes (tissue macrophages). It is Subdivided into three Categories:- Letterer-siwe syndrome Hand-Schuller-Christian disease Eosinophilic granuloma. Tumor cells in each are derived from dendritic cells and express S-100, CD la and HLA-DR. The presence of Birbeck granules in the cytoplasm is characteristic. Under electron microscope, Birbeck granules have a pentalaminar, rod like, tubular appearance and sometimes a dilated terminal end (tennis-rachet appearance).