You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is Localised langerhans cells histiocytosis affecting head & neck is - and explain in detail?
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