CD marker of histiocytosis is -

Ans. is 'a' i.e., GDI A o CDIA is a T cell surface antigen important in dendritic cell presentation of glycolipids and lipopeptide antigeno It is used to diagnose Langerhans cell histiocytosis.o The presence of Birbeck granules in the cytoplasm of tumor cells is characteristic of Langerhans cell histiocyteo As Birbeck granules are not seen in all tumor cells by election microscopy the detection of S-100 and CDla expression by immunohistochemical techniques aids in the diagnosis.o Other immunohistochemical markers of Langerhans cell histiocytosis are: -HLA-DRLangerin (CD 207)CD 68