A 2 year old child presents with scattered lesions in the skull. Biopsy revealed Langerhans giant cells. The most commonly associated is marker with this candition will be: (A) CD 1a, (B) CD 57, (C) CD 3, (D) CD 68
Answer is A. In Langerhans cell histiocytosis,the hallmark feature is the presence of Birbeck granules on electron microscopy and positivity for S-100 protein and CD 1a. Reference:Essential pediatrics-Ghai,8th edition,page no:620.