Birbeck granules in cytoplasm is seen in -

Ans. is 'a' i.e., Langerhans cell histiocytosis Birbeck granules are characteristic of langerhans cell histiocytosisTumour cells in the laneerhan \ cell histiocytosis are derived from dendritic cells and express :-o S-100o CDlao HLA-DRo These cells are characterized by the presence of birbeck granules in their cytoplasm unde rthe electron micro-scope, Birbeck granules have pentalaminar, rodlike tuular appearance and sometimes a dilated terminal end itennis-racket appearance)