This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
Presence of Birbeck granules in histopathological examination suggests: 
Select and explain. 
A. Plasmacytoma., B. Burkett lymphoma., C. Langerhan cells histiocytosis., D. All of the above
C: Langerhan cells histiocytosis.
Answer: C: Langerhan cells histiocytosis. 
Explanation: The old term histiocytosis X is replaced by new term called Langerhans cell histiocytois (LCH). The presence of birbeck granules is characteristic finding in LCH.