You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is CD marker of histiocytosis is ? and explain in detail?
Ans. is 'a' i.e., CD1A CD1A is a T cell surface antigen impoant in dendritic cell presentation of glycolipids and lipopeptide antigens. It is used to diagnose Langerhans cell histiocytosis. The presence of Birbeck granules in the cytoplasm of tumor cells is characteristic of Langerhans cell histiocytosis. As Birbeck granules are not seen in all tumor cells by election microscopy the detection of S-100 and CD1a expression by immunohistochemical techniques aids in the diagnosis. Other immunohistochemical markers of Langerhans cell histiocytosis are HLA-DR, Langerin (CD 207), and CD 68.