This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Haematology, Subject name: Pathology
Localised langerhans cells histiocytosis affecting head & neck is - 
Select and explain. 
A. Letterer-siwe disease, B. Pulmonary langerhans cell histiocytosis, C. Hand-schuller-christian disease, D. Eosinophilic granuloma
D: Eosinophilic granuloma
Answer: D: Eosinophilic granuloma 
Explanation: Unifocal and multifocal unisystem Langerhans cell histiocytosis(eosinophilic granuloma)is characterised by proliferation of Langerhans cells admixed with variable number of eosinophils , lymphocytes , plasma cell, and neutrophils .Eosinophils are usually , but not always a prominent component of the infiltrate .It typically arises within the medullary cavities of bones, most commonly the calvarium, ribs and femur. ref: Robbins pathologic basis of disease ; 8th edition ; pg 632