<prompt> Birbeck granules in the cytoplasm is seen in:Langerhans cellsMast cellsMyelocytesThrombocytes  <response>: Langerhans cells: Ref: 701-702-R, 463-HM 467-Basicpathology tfh The presence of Birbeck granules in the cytoplasm is characteristic of Langerhans cell histiocytosis Tennis- rachet appearance As Birbeck granules are not seen in all tumours cells by electron microscopy the detection of 5-100 and CDla expression by immuno histochemical techniques aids in the diagnosis 