Pediatrics C.V.S. 3c2e90e7 CD marker of histiocytosisis: A CD 1a B CD 1b C CD 1c D CD 1d High-Yield Explanation a. CD 1 a(Ref: Nelson's 20/e p 2484-2489, Ghai 8/e p 620-623)Immunohistochemistry shows: CD1a, S-100 or Langerin (CD 207) in Histiocytosis.